II.3.1 Adjustement of acidity of wine

II.3.1.1.1 Chemical acidification

Classification:

• Lactic acids, L(-): Additive
• D,L malic acid: Additive
• L(+) tartaric acid: Additive
• citric acid: Additive

Definition:

Increasing the titration acidity and the actual acidity (decreasing pH) by adding organic acids.

Objectives:

a)        Produce balanced wines from the gustatory point of view;

b)       Favor a good biological evolution and good maturation of wine

c)        Remedy insufficient natural acidity caused by:

• climatic conditions in the viticulture region, or
• oenological practices which lead to a decrease in natural acidity

Prescriptions:

a)        Lactic acids, L(-) or DL malic acid and L(+) tartaric and citric acids are the only acids that can be used;

b)       Citric acid content in wine after this procedure should not exceed the limit established in Annex C of the International Collection of Methods for Wine and Must Analysis

c)        The addition of acids should not be done to conceal fraud;

d)       The addition of mineral acids is forbidden;

e)       Chemical acidification and chemical de-acidification are mutually exclusive;

f)         The acids used must conform to the International Oenological Codex standards

g)        Acids can be only be added to wine under condition that the initial acidity is not increased by more than 54 meq/l (i.e. 4 g/l expressed as tartaric acid),

When musts and wine are acidified, the cumulated dose must not exceed a net cumulative increase of 54 meq/l (or 4 g/l expressed as tartaric acid),

Recommendation of the OIV:

Admitted

II.3.1.1.3 Treatment with ion exchangers

Definition:

Operation consisting of passing the wine through a column of polymerised resin that acts as an insoluble polyelectrolyte whose ions are able to be exchanged with ions of the wine. According to their polar groupings, ion exchange resins are categorised as cation exchangers and anion exchangers.

Objectives :

a)        Treatment with cation exchangers:

1. To stabilise the wine with regard to tartrate precipitation (see II.3.3.3 ‘Tartrate stabilisation by treatment with cation exchangers’),
2. To lower the pH of wines of low fixed acidity and high in  cations,
3. To avoid metallic hazes.

b)       Treatment with anion exchangers:

1. To reduce the titratable acidity,
2. To de-sulphite wines,
3. To reduce the sulphate content.

Recommendation of OIV :

• For objective a)1 and a)2 : Admitted
• For the other objectives: Not admitted

II.3.1.1.4 Acidification by electromembrane treatment (bipolar membrane electrodialysis)

Definition:

Physical method for ionic extraction in wine under the action of an electric field using membranes permeable only to cations on the one hand, and bipolar membranes on the other hand, and enabling an increase of titratable acidity and actual acidity (decrease of the pH).

Objectives:

a)        increase of titratable acidity and actual acidity (decrease of the pH).

b)       Obtaining wines with balanced taste characteristics.

c)        Promote a good biological evolution and proper storage of the wine.

d)       Remedy insufficient natural acidity caused by:

• climatic conditions in the viticulture region, or
• oenological practices which lead to a decrease in natural acidity.

Prescriptions:

a)        See the general sheet pertaining to separative techniques used in the treatment of wines and musts and the sheet pertaining to the use of membrane techniques applied to musts.

b)       Acidification by electro-membrane treatment should not be done to conceal fraud.

c)        Cationic membranes shall be made in such a way so as to be only adapted to the extraction of cations only and in particular cations: K⁺.

d)       Bipolar membranes are impermeable to anions and to wine cations.

e)       The acidification by bipolar electrodialysis can only be carried out if initial must acidity has not been increased more than 54 meq/l

When must and wine are acidified, the total increased acidity must not exceed 54 meq/l.

f)         The implementation of the process will be under the responsibility of an oenologist or a qualified technician.

g)        The membranes shall comply with the prescriptions of the International Oenological Codex.

Recommendation of the OIV:

Admitted

II.3.1.2.2 Chemical de-acidification

Classification :

• Potassium L(+) tartrate: processing aid
• Potassium hydrogen tartrate: processing aid
• Calcium carbonate: processing aid
• Potassium hydrogen carbonate: processing aid

Definition :

Reduction of the acidity and the actual acidity (increase of the pH) by addition of neutral potassium tartrate, potassium hydrogen carbonate or calcium carbonate possibly containing a small quantity of the calcium double salt of L(+) tartaric and L(-) malic acids

Objectives :

a)       See II.3.1.2 ‘De-acidification’

b)       To favour biological de-acidification.

Prescriptions :

a)        The de-acidified wine shall contain at least 1 g/l tartaric acid.

b)       The process of the formation of double salt (neutral calcium salt of tartaric and malic acids) is intended to produce a greater reduction in titratable acidity, when the wine has a high malic acid content and the precipitation of tartaric acid alone does not prove sufficient.

c)        Chemical de-acidification should be performed in such a way that the wines obtained do not lack acidity, taking account of a possible subsequent malolactic fermentation.

d)       The aim of chemical de-acidification shall not be to conceal fraud.

e)       The elimination of excess carbon dioxide can be achieved, if necessary, by flushing with nitrogen.

f)         Chemical acidification and chemical de-acidification are mutually exclusive

g)        The products used shall comply with the prescriptions of the International Oenological Codex.

Recommendation of OIV :

Admitted

II.3.1.2.3 Microbiological de-acidification

Definition :

Reduction of the titratable acidity and the actual acidity (increase of the pH) by malolactic fermentation.

Objective :

To produce wines :

a)       See II.3.1.2 ‘De-acidification’

b)       Biologically more stable.

Prescriptions :

To achieve the objectives, the microbiological de-acidification by lactic acid bacteria can be performed either in a spontaneous manner or by inoculation of selected strains.

a)        The sulphur dioxide content should be limited, lactic acid bacteria being very sensitive to the presence of this compound,

b)       It is desirable that malolactic fermentation takes place at the end of the alcoholic fermentation, to avoid bacterial degradation of sugars,

c)        The wine in which malolactic fermentation is to occur should be maintained at a temperature of approximately 18°C.

d)       Where selected cultures of lactic acid bacteria are used, these shall comply with the prescriptions of the International Oenological Codex

Recommendation of OIV :

Admitted

II.3.1.2.4 De-acidification using an electromembrane process

Definition:

Physical method of ionic extraction from the wine under the action of an electric field using permeable membranes with anions on the one part and bipolar membranes on the other. The combination of permeable membranes with anions and biopolar membranes is used to manage a reduction in titratable acidity and the actual acidity (increase in the pH)

Objectives:

a)        Correct excess natural acidity caused by climate conditions in the wine region by reducing titratable acidity and actual acidity (increase in the pH)

b)       Develop balanced wines in terms of taste

Prescriptions:

a)        Refer to the general file on separative techniques used in the processing of musts and wines and the file on the application of membrane techniques to wines.

b)       De-acidification using an electromembrane process should not be intended to hide a fault.

c)        The anionic membranes must be placed in such a way that they only allow the extraction of anions and in particular the organic acids from the wine.

d)       The bipolar membranes are impermeable to anions and cations in the wine.

e)       The wine from a de-acidified wine should contain at least 1g/L of tartaric acid.

f)         De-acidification by membrane process and acidification are mutually exclusive;

g)        An oenologist or qualified technician will be responsible for implementing the process.

h)       The membranes used must comply with the prescriptions contained in the “International Oenological Codex”

Recommendation of the OIV

Admitted

II.3.2 Clarification of wine

II.3.2.2 Filtration

Classification:

• Diatomite: processing aid
• Perlite: processing aid

Definition:

Physical process consisting of passing the wine through appropriate filters that retain particles in suspension.

Objectives:

a)        Clarifying the wine, if necessary by successive stages (clarifying filtration).

b)       Obtaining biological stability of the wine by elimination of microorganisms (sterilising filtration).

Prescriptions:

Filtration can be undertaken:

a)        By continuous deposition, using appropriate additives such as diatomaceous earth, perlite, cellulose…,

b)       On pads of cellulose or other appropriate materials,

c)        On mineral or organic membranes of a porosity greater than or equal to 0.2 m (microfiltration).

The filter materials used shall comply with the prescriptions of the International Oenological Codex.

Recommendation of OIV:

Refer to the practices and treatments mentioned hereafter.

II.3.2.2.1 Filtration by continuous deposition

Definition :

Filtration of the wine, after formation of a filter bed, which is then fed constantly by a continuous addition of filter material into the wine to be clarified.

Objective :

To obtain a suitable level of clarity, to a given technological stage, by the elimination of substances in suspension in the wine.

Prescriptions :

a)        The nature of the filter material (such as diatomaceous earth, perlite and cellulose) and the necessary dose are determined by the turbidity of the wine and the clarification sought.

b)       The filter materials used shall comply with the prescriptions of the International Oenological Codex. 

Recommendation of OIV:

Admitted

II.3.2.2.2 Sterilising filtration

Definition:

Filtration of wines on materials allowing the elimination of microorganisms.

Objective :

To obtain biologically stable wines for bottling.

Prescriptions :

a)        The objective can be achieved by the use of the following, having regard to conditions of pressure, flow and recommended duration:

• Special prefabricated pads of cellulose or other materials;
• Membranes having a maximum average pore diameter of 0.65 µm.

b)       The filtration equipment must be sterilised beforehand by passing hot water or steam through them.

c)        The materials used shall comply with the prescriptions of the International Oenological Codex.

Recommendation of OIV :

Admitted

II.3.2.3 Racking

Classification:

• Nitrogen: processing aid
• Argon: processing aid

Definition :

Operation involving the transfer of wine from one wine container to another by allowing the separation of solid deposits from the liquid.

Objectives:

a)        Separate wine from the lees, and/or the deposits resulting from the addition of clarifying agents, deposited at the bottom of the container

b)       Separate the wine from the micro-organisms at the end of the alcoholic and/or malolactic fermentation, or the bacterial or yeast sediment

c)        Enable the carrying out of all wine making operations, treatment or transportation of wines.

d)       Enable the tartaric stabilization by cooling and the separation of tartrate crystals (potassium bitartrate and calcium tartrate).

Prescriptions :

Racking can occur:

a)        Either in the absence of air to avoid oxidation,

b)       Or with aeration to eliminate hydrogen sulfide or to reduce carbon dioxide or to create controlled oxidation,

c)        Or at room temperature, or after cooling to avoid possible carbonic gas loss,

d)       Or using the law of interconnected vessels, either with pumps or hand containers

e)       In the case of racking in the absence of air, the container to be filled must be rendered inert with carbon dioxide, nitrogen or with argon. These gases must comply with International Oenological Codex prescriptions.

Recommendation of OIV:

Admitted

II.3.2.4 Treatment with silicon dioxide

Classification:

• Colloidal silicon dioxide solution: processing aid

Definition :

Addition to wine of a colloidal solution (gel) of silicon dioxide coupled with the addition of a gelatin solution or, possibly, with other proteinaceous finings.

Objective :

To achieve the flocculation of the gelatin and possibly other proteinaceous finings, with a view to clarification.

Prescriptions :

a)        The product is added to young white wines and rosés and occasionally to red wines.

b)       Preliminary tests are necessary to determine optimal doses of the colloidal solutions of silicon dioxide and gelatin or possibly, of other proteinaceous finings.

c)        The products shall comply with the prescriptions of the International Oenological Codex.

Recommendation of OIV:

Admitted

II.3.2.5 Decanting

Definition :

Operation consisting of transferring from one wine tank to another:

A still wine at normal pressure,

Objectives :

a)        To separate wines from their lees, deposited on the bottom of the container.

b)       To prepare for mixing or blending operations.

c)        To prepare for physical clarification by filtration, centrifugation, etc.

d)       To achieve bulk transportation of the wine.

Prescriptions :

Decanting can be performed:

a)        Either under protection from air so as to avoid all oxidation, or

b)       With aeration, to eliminate hydrogen sulphide or to reduce the carbon dioxide or to create a managed oxidation.

Recommendation of OIV:

Admitted

II.3.2.6 Tannin addition

Definition:

Addition of tannins to wine.

Objectives:

a)        To facilitate the stabilisation of wines by partial precipitation of excess proteinaceous matter;

b)       to facilitate the fining of wines in conjunction with protein-type fining agents and prevent over-fining;

c)        to contribute to the antioxidant and antioxidasic protection of compounds of the wine;

d)       to promote the expression, stabilisation and preservation of colour in red wines.

Prescription:

The tannins used should comply with the prescriptions of the International Oenological Codex .

Recommendation of OIV:

Admitted

II.3.2.7 Fining using proteins of plant origin

Classification:

• Protein of plant origin from wheat: processing aid
• Protein of plant origin from peas: processing aid
• Protein of plant origin from potatoes: processing aid

Objectives :

Use of protein matter of plant origin for the fining of wines in order to improve their clarity, stability and gustatory properties.

Prescriptions:

a)        The doses to be used are determined after a preliminary test trial. The maximum usage dose should be less than 50 g/hl. After racking, the wines are analysed (turbidity, colour, absorbance at 280nm) and tasted. The dose retained corresponds to the sample which clarifies the wine without excess and gives a better result for tasting.

b)       Proteins of plant origin can be used with other admitted products such as tannins, bentonite, silica gel

c)        Proteins of plant origin must comply with the prescriptions of the International Oenological Codex.

Recommendation of OIV:

Admitted

II.3.2.8 Use of enzymes for improving filterability of wines

Classification :

• Arabinanases : processing aid
• Cellulases: processing aid
• Pectinlyases: processing aid
• Pectinemethylesterase: processing aid
• Polygalacturonases: processing aid
• Hemicellulases: processing aid

Definition:

Addition to wine of enzymatic preparations containing activities catalysing the degradation of plugging macromolecules of grapes which went into the must and in wine during the vinification process, as well as plugging macromolecules of bacterial or fungal origin.

Enzyme activities involved in improving the filterability of wines notably include arabinanases, rhamnogalacturonases, and hemicellulases, and to a lesser extent polygalacturonases, pectin lyases and pectinmethylesterases, as well as β-glucanases if wines come from botrytised grapes or have a high glucans content from yeast cell walls

Objective:

To improve the filterability of wines by specific hydrolysis of colloids.

Prescription:

The enzymes used must comply with the prescriptions of the International Oenological Codex.

Recommendation of OIV:

Admitted

II.3.2.9 Use of enzymes for the release of flavouring compounds from glycosylated precursors

Classification :

• Glycosidases: processing aid
• Glucosidases: processing aid

Definition:

Addition to wine of enzymatic preparations containing activities catalysing the hydrolysis of the saccharide portion of the glycosylated aromatic substances (flavour precursors) of grapes which went into the must and the wine during the vinification process.

The enzymatic activities involved in the release of flavouring substances are glycosidases and glucosidases.

Objective:

to enhance the aromatic potential of wine

Prescription:

The enzymes used must comply with the prescriptions of the International Oenological Codex.

Recommendation of OIV:

Admitted

II.3.2.10 Use of enzymes for improving the solubilization of yeast compounds

Classification:

• Beta-glucanases : processing aid

Definition:

The addition to wine during winemaking on lees of enzymatic preparations notably with β-glucanase activities that catalyse the degradation of yeast cell walls.

Objectives:

a)        To facilitate the release of yeast-soluble constituents into wine.

b)       To improve the colloidal stability of wines.

Prescription:

The enzymes used must comply with the prescriptions of the International Oenological Codex.

Recommendation of OIV:

Admitted

II.3.2.11 Use of enzymes for the clarification of wines

Classification:

• Arabinanases : processing aid
• Cellulases: processing aid
• Pectinlyases: processing aid
• Pectinemethylesterase: processing aid
• Polygalacturonases: processing aid
• Hemicellulases: processing aid
• β-glucanases : processing aid

Definition:

Addition to wine of enzymatic preparations containing activities catalysing the degradation of grape macromolecules which went into the must and wine, as well as macromolecules of bacterial or fungal origin.

Enzyme activities involved in the clarification of wines notably include polygalacturonases, pectin lyases, pectinmethylesterases, and to a lesser extent arabinanases, rhamnogalacturonases, cellulases and hemicellulases, as well as β-glucanases  if wines come from botrytised grapes

Objective:

To facilitate the clarification of wines.

Prescription:

The enzymes used must comply with the prescriptions of the International Oenological Codex.

Recommendation of the OIV

Admitted

II.3.2.12 Fining using chitosan

Classification :

• Chitosan : processing aid

Definition:

Addition of chitosan of fungal origin for the purpose of fining wines

Objectives:

a)        To reduce turbidity by precipitating particles in suspension.

b)       To carry out a treatment to prevent protein haze by the partial precipitation of excess proteinaceous matter.

Prescriptions:

a)        The doses to be used are determined after preliminary testing. The maximum dose used must not exceed 100 g/hl.

b)       Sediments are eliminated by physical procedures.

c)        Chitosan of fungal origin may be used alone or together with other admitted products.

d)       Chitosan must comply with the requirements of the International Oenological Codex.

Recommendation of the OIV

Admitted

II.3.2.13 Fining using chitin-glucan

Classification:

• chitin-glucan: Processing aid

Definition:

Addition of chitin-glucan of fungal origin for the purpose of fining wines

Objectives:

a)        To reduce turbidity by precipitating particles in suspension

b)       To carry out a treatment to prevent protein haze by the partial precipitation of excess proteinaceous matter.

Prescriptions:

a)        The doses to be used are determined after preliminary testing. The maximum dose used must not exceed 100 g/hl.

b)       Sediments are eliminated by physical procedures.

c)        Chitin-glucan of fungal origin may be used alone or together with other admitted products.

d)       Chitin-glucan must comply with the requirements of the International Oenological Codex.

Recommendation of the OIV

Admitted

II.3.2.14 Fining using yeast protein extracts

Classification:

• Yeast protein extracts: processing aid

Definition:

Addition of yeast protein extracts for fining wines

Objectives:

a)        Reduce turbidity of wines by precipitating suspended particles

b)       Preserve chromatic characteristics of wines

c)        Eliminate excess tannin

d)       Improve wine filterability

Prescriptions:

a)        The doses used are determined beforehand by laboratory trials (fining point)

b)       Maximum dose to be used as determined by an efficiency test conducted in laboratory must not exceed 60 g/hl for red wine and 30 g/hl for white and rosé wine

c)        The yeast protein extracts can be used alone or associated with other authorised fining products

d)       The deposits from the fining are to be eliminated from wine by physical procedures

e)       The yeast protein extracts must comply with the prescriptions of the International Oenological Codex

Recommendation of the OIV:

Admitted.

II.3.2.15 Use of filter plates containing zeolites Y-Faujasite to adsorb halonisoles

Definition

Treatment using a filter plate containing zeolites Y-faujasite applied during filtration.

Objectives

a)        To reduce the concentration of haloanisoles responsible for off-flavour in wines, below their sensory perception threshold.

Prescriptions

a)        the treatment should be carried out on clarified wines;

b)       the filter plates should be cleaned and disinfected before filtration;

c)        the application of zeolites Y-faujasite should comply with the prescriptions in the International Oenological Codex.

Recommendation of the OIV:

Admitted

II.3.3 Physico-chemical stabilisation of wine

II.3.3.1 Removal of iron

Classification :

• Potassium hexacyanoferrate (II): processing aid
• Calcium phytate : processing aid

Definition :

Treatment designed to eliminate excess iron in wine.

Objective :

Prevention of iron hazes.

Prescription :

One of the following treatments is used, with or without a combined oxygenation:

• Tannin addition and fining,
• Addition of calcium phytate,
• Use of potassium ferrocyanide,
• Use of iron-removing carbon (not accepted),
• Use of citric acid.

Recommendation of the OIV:

Refer to the treatments and practices mentioned above.

II.3.3.2 Tartrate stabilisation by electrodialysis

Definition :

Physical method for the extraction of ions in super-saturation in the wine under the action of an electric field with the help of membranes permeable only to anions on the one hand, and membranes permeable only to cations on the other hand.

Objective :

To obtain a tartrate-stable wine:

• With respect to potassium hydrogen tartrate
• With respect to calcium tartrate (and other salts of calcium).

Prescriptions :

a)        The membranes are flat and arranged alternately in a system typical of a filter-press, that establishes compartments of processing (wine) and concentration (reject water).

b)       Cation exchange membranes shall be adapted to the extraction of only cations and in particular: K+, Ca++.

c)        Anion exchange membranes shall be adapted to the extraction of only anions and especially of tartrate anions.

d)       The equipment used will be operated under a control system that takes into account the instability of each wine in such a way that only the super-saturation in potassium hydrogen tartrate and in salts of calcium is eliminated.

e)       The implementation of the process will be under the responsibility of an oenologist or specialist technician.

f)         The membranes shall comply with the prescriptions of the International Oenological Codex and shall not to lead to excessive modifications of the physico-chemical composition and sensory characteristics of the wine.

Recommendation of OIV

Admitted

II.3.3.3 Tartrate stabilisation by treatment with cation exchangers

Definition :

Operation consisting of passing the wine through a column of polymerised resin that reacts as an insoluble polyelectrolyte whose cations are able to be exchanged with cations of the surrounding medium.

Objective :

To obtain a tartrate-stable wine:

• With respect to potassium hydrogen tartrate
• With respect to calcium tartrate (and other salts of calcium).

Prescriptions :

a)        The treatment must be limited to the elimination of excess cations.

• The wine may be initially cold treated.
• Only the minimum fraction of a wine necessary for obtaining stability will be treated with cation exchangers.

b)       The treatment will be performed using cation exchange resins regenerated in the acid cycle.

c)        The whole process will be placed under the responsibility of a oenologist or specialist technician.

d)       The resins shall comply with the prescriptions of the International Oenological Codex and shall not lead to excessive modifications of the physico-chemical composition and sensory characteristics of the wine.

Recommendation of OIV

Admitted

II.3.3.4 Cold stabilisation

Definition :

Operation that consists of chilling the wine.

Objectives :

a)        To promote the crystallisation and precipitation of potassium and calcium tartrates, the precipitation of colloids and also to improve the stability of wine.

Prescriptions :

• For objective (a), the treatment is performed using mechanical refrigeration or natural cold sources, with or without addition of potassium bitartrate crystals followed by the separation by physical techniques of the crystals and colloids precipitated.

Recommendation of OIV :

Admitted

II.3.3.5 Treatment with bentonites

Classification:

• Bentonites: processing aid

Definition

Addition of bentonites to wine.

Objective :

To prevent protein and copper hazes.

Prescription :

The substances used shall comply with the prescriptions of the International Oenological Codex

Recommendation of the OIV:

Admitted

II.3.3.6 Treatment with gum arabic

Classification :

• Arabic gum : additive

Definition :

Addition of gum arabic to wine.

Objectives :

a)        To avoid copper haze.

b)       To protect wine against light iron haze.

c)        To prevent the precipitation of substances such as pigments that, in the wine, are in the colloidal state.

Prescriptions :

a)        The product should be added to the wine after the last filtration, or just before bottling.

b)       The dose used shall not exceed 0.3 g/l.

c)        The gum arabic shall comply with the prescriptions of the International Oenological Codex

Recommendation of OIV:

Admitted

II.3.3.7 Treatment with metatartaric acid

Classification:

Metartaric acid: additive

Definition :

Addition of metatartaric acid to wine.

Objective :

To prevent the precipitation of potassium hydrogen tartrate and calcium tartrate.

Prescriptions :

a)        The addition should take place only at the last moment, before bottling.

b)       The dose used shall be less than or equal to 10 g/hl.

c)        The duration of protection depends on the storage temperature of the wine, because the acid in question hydrolyses slowly in the cold, but rapidly under hot conditions.

d)       The metatartaric acid shall comply with the prescriptions of the International Oenological Codex.

Recommendation of the OIV:

Admitted

II.3.3.8 Treatment with citric acid

Classification:

• Citric acid, monohydrate : additive

Definition :

Addition of citric acid to wine.

Objective :

To bind ferric ions in a soluble complex anion and thus to lessen the tendency to form iron hazes.

Prescriptions :

a)        The maximum citric acid content of the wine at the point of consumption shall be 1 g/l.

b)       The citric acid used shall comply with the prescriptions of the International Oenological Codex.

Recommendation of the OIV:

Admitted

II.3.3.9 Treatment with iron-removing carbon

Definition :

Addition to wine of carbon specially prepared for the removal of iron from wines.

Objective :

To prevent iron hazes.

Recommendation of OIV:

Not admitted

II.3.3.10 Treatment with potassium ferrocyanide

Classification:

• potassium ferrocyanide: Processing aid

Definition :

Addition of potassium ferrocyanide to wine.

Objective :

To lessen the wine’s content:

• Of iron to avoid iron hazes,
• Of copper to avoid copper hazes,
• And more generally of heavy metals.

Prescriptions :

a)        This procedure can be executed only by a responsible and qualified technician.

b)       The main operation must be preceded by trials to determine the amount of product to add.

c)        The main operation should be followed by an examination of the treated wine, to determine the absence of an excess of ferrocyanide or its derivatives.

d)       The potassium ferrocyanide used shall comply with the prescriptions of the International Oenological Codex .

Recommendation of OIV:

Admitted

II.3.3.11 Treatment with calcium phytate

Classification:

• calcium phytate: Processing aid

Definition :

Addition to wine of calcium phytate (or the calcium salt of the hexaphosphoric ester of inositol).

Objective :

To prevent iron hazes in the case of wines high in iron, but having no excess copper.

Prescriptions :

a)        It is necessary to perform preliminary tests and performance trials, given that the treatment gives uncertain results.

b)       The use of hydrochloric acid to dissolve calcium phytate before its addition to the wine is positively forbidden.

c)        The calcium phytate used shall comply with the prescriptions of the International Oenological Codex.

Recommendation of the OIV:

Admitted

II.3.3.12 Calcium tartrate treatment

Classification:

• Calcium tartrate: processing aid

Definition:

Addition of calcium tartrate to wine.

Objective:

to contribute to the tartaric stabilisation of wine by decreasing the content of potassium hydrogenotartrate and calcium tartrate.

Prescriptions:

a)        The dose used must be inferior to 200g/hl.

b)       The treatment is carried out by calcium tartrate addition, stirring and artificial cooling of the wine followed by the separation with crystals formed by physical means.

c)        Calcium tartrate must conform to the prescriptions of the International oenological codex.

Recommendation of the OIV:

Admitted

II.3.3.13 Treatment of wines with yeast mannoproteins

Classification:

• Yeast mannoproteins: additive

Definition:

Treatment of wines by using mannoproteins from yeast wall degradation.

Objective:

Improve stability of wine only with regards to tartaric salts and/or its proteins in the case of white or rosé wines

Prescriptions:

a)        The doses that should be used will be established by the person in charge of the treatment;

b)       for certain young red and rosé wines the person in charge of the treatment should consider a pre-treatment using yeast cell walls if the mannoproteins alone do not present the sought after efficiency;

c)        Mannoproteins must comply with the provisions of the International Oenological Codex.

Recommendation of OIV:

Admitted

II.3.3.14 Treatment with Cellulose gums (Carboxymethylcellulose)

Classification:

• Sodium Carboxymethylcellulose: additive

Definition:

Addition of cellulose gums to white, rosé and sparkling wines

Objective:

Contribute to the tartaric stabilisation of white wine and sparkling wine

Prescriptions:

a)        The dose of carboxymethylcellulose to be used should be below 200 mg/

b)       For questions of incorporation, it is preferable to use products in granulated form or less viscous products.

c)        Carboxymethylcellulose may cause instability in the presence of proteins and polyphenols

d)       Cellulose gums used must be in accordance with the provisions of the International Oenological Codex.

Recommendation of the OIV:

Admitted.

II.3.3.15 Treatment with potassium polyaspartate

Classification:

• Potassium polyaspartate: additive

Definition:

Addition of potassium polyaspartate to wines

Objective:

Contribute to the tartaric stabilization of wines

Prescription:

a)        The optimum dose of potassium polyaspartate used to stabilize wines, also those with a high degree of tartaric instability, must not exceed 10 g/hL. At higher doses, the potassium polyaspartate’s (KPA) stabilizing performance is not improved and, in some cases, an increase of wine turbidity could be induced;

b)       for red wines with high colloidal instability, prior treatment with bentonite is recommended;

c)        the application of potassium polyaspartate must be in accordance with the prescriptions of the International Oenological Codex.

Recommendation:

Admitted

II.3.3.16 Use of Aspergillopepsin I to remove haze-forming proteins

Definition:

The addition to wine of Aspergillopepsin I from Aspergillus spp. to remove haze-forming proteins

Objective:

To prevent protein haze in still white and rosé wines and sparkling wines.

Prescription:

a)        After addition of Aspergillopepsin I preparation, one short-term wine heating must be applied as it contributes to the unfolding of haze-forming proteins and facilitates their enzymatic degradation by proteases, as well as leads to a denaturation of the protease itself.

This single heat treatment must take into account:

• the activity of the Aspergillopepsin I preparation as regards temperature
• the quantity of Aspergillopepsin I used
• The minimum temperature of treatment should be at or above the denaturation temperature of the proteins, generally comprised between 60 and 75 °C.
• the heating time, generally around 1 minute. Too long heating time could induce negative organoleptic impact.

This loss of three-dimensional conformation of TLPs (Thaumatin Like Proteins) is reversible, so the heating has to be simultaneous to the addition of enzymes for optimal efficiency.

b)       The wine is immediately cooled to an appropriate temperature.

c)        A filtration must be performed to remove the residual proteins (including added proteases and other proteins).

d)       The enzymes used must comply with the prescriptions of the International Oenological Codex.

Recommendation:

Admitted

II.3.4 Protection and preservation of wine

II.3.4.1 Topping up

Definition :

Operation consisting of the addition of wine to a wine container in order always to keep it full and to compensate for normal storage losses.

Objective :

To avoid all contact of the wine with air which could lead to oxidation or aerobic microbial growth.

Prescription :

The wine used for topping up should be the same wine or to have similar characteristics to those of the wine to which it is added so as not to modify its quality.

Recommendation of OIV :

Admitted

II.3.4.3 Pasteurisation

Definition :

Heating wine to a specified temperature for a given time.

Objectives :

a)        To inhibit the activity of microorganisms present in the must at the time of treatment.

b)       To inactivate enzymes present in the wine.

Prescriptions :

a)        Pasteurisation can be performed :

• In bulk (see II.3.4.3.1 ‘Bulk pasteurisation’);
• In bottle (see II.3.5.10 ‘In-bottle pasteurisation’).

b)       Pasteurisation can be achieved using different techniques.

• By passage of the wine through a heat exchanger followed by rapid cooling.
• By bottling and corking the wine hot, followed by natural cooling (see II.3.5.4 ‘Hot bottling’)
• By heating the wine in bottles, followed by cooling.

c)        The increase in temperature and the techniques used shall cause no alteration in the appearance, colour, odour or taste of the wine.

Recommendation of OIV:

Refer to the practices and treatments mentioned above.

II.3.4.3.1 Bulk pasteurisation

Classification :

• Liquide sulphur dioxide: additive

Definition :

Heating wine to a specified temperature for a given time.

Objectives :

a)       See II.3.4.3 ‘Pasteurisation’

b)       To inactivate oxidative enzymes when they are present in the wine.

Prescriptions :

a)        Bulk pasteurisation is performed by passing the wine through a heat exchanger followed by cooling.  It can take two forms:

• Simple pasteurisation,
• Flash pasteurisation.
• Flash pasteurisation is distinguished from simple pasteurisation by rapid heating, to a higher temperature, for a very short time, followed by rapid cooling.

b)       The treatment should not produce any alteration in the clarity, colour, odour or taste of the wine.

Recommendation OIV:

Admitted

II.3.4.4 Sulphiting

Classification:

• Sorbic acid: additive
• Potassium sorbate: additive

Definition:

The addition of gaseous sulphur dioxide, sulphuric solutions or potassium metabisulphite solutions to wine.

Objectives:

a)        To obtain the microbiological stabilisation of wine by limiting and/or preventing the growth of yeast and technologically unwanted bacteria,

b)       To use its reducing and antioxidant properties,

c)        To combine certain molecules that give undesirable odours,

d)       To inhibit possible oxidasic activities.

Prescriptions:

a)        The total sulphur dioxide contents when marketed must at least comply with the limits set by Annex C of the Compendium of International Methods of Analysis of Wine and Musts.

b)       The addition of sulphur dioxide can be carried out by:

• the direct addition to wine during the wine making process,
• the direct addition to the wine prior to bottling,
• the direct injection to the wine prior to filling,
• the direct injection in the empty bottle prior to filling.

c)        The products used must comply with the prescriptions of the International Oenological Codex.

Recommendation of the OIV:

Admitted.

II.3.4.5 Treatment with sorbic acid

Classification:

• Sorbic acid: Additive

Definition :

Addition to wine of sorbic acid or potassium sorbate.

Objectives :

a)       See II.3.4.2 ‘Biological stabilisation’

b)       To prevent the re-fermentation of wines containing fermentable sugars.

c)        To prevent the development of undesirable yeasts.

Prescriptions :

a)        The addition should take place only a shortly before bottling.

b)       The dose used shall not exceed 200 mg/l expressed as sorbic acid.

c)        The sorbic acid and potassium sorbate shall comply with the prescriptions of the International Oenological Codex

Recommendation of the OIV:

Admitted

II.3.4.6 Treatment with oils

Definition :

Use of mineral oils.

Objective :

To eliminate accidental taints in wine by intimate mixing of the oil and the wine.

Recommendation of the OIV:

Not admitted

II.3.4.8 Treatment with diethyl decarbonate

Definition :

Addition of diethyl dicarbonate to wine.

Objective :

To stabilise wine from a biological point of view by chemical treatment.

Recommendation of OIV :

Not admitted

II.3.4.9 Treatment with polyvinylpolypyrrolidone (PVPP)

Classification:

• Polyvinylpolypyrrolidone: processing aid

Definition:

Addition to wine of polyvinylpolypyrrolidone (PVPP).

Objectives :

To reduce the content of tannin and other polyphenols in the wine with a view:

• To overcoming the tendency to brown,
• To reducing the astringency,
• To correcting the colour of slightly discoloured white wine.

Prescriptions :

a)        The dose of PVPP used shall not exceed 80 g/hl.

b)       The PVPP used shall comply with the prescriptions of the International Oenological Codex .

Recommendation of OIV :

Admitted

II.3.4.10 Treatment with polyamides

Definition :

Addition to wine of a powder or paste of polyamide.

Objectives :

a)        To reduce the content of tannin and other polyphenols in wine.

b)       To combat the tendency to browning.

Recommendation of OIV:

Not admitted

II.3.4.11 Treatment of wines with urease

Classification:

• Urease: processing aid

Definition:

Addition to wine of an active acid urease, produced from Lactobacillus fermentum.

Objective :

To reduce the level of urea in wines, when this is excessive, in order to avoid the formation of ethyl carbamate during ageing.  The enzyme transforms urea into ammonia and carbon dioxide.

Prescriptions :

a)        It is preferable to add the urease to wine already clarified by spontaneous sedimentation of the lees.

b)       A knowledge of the level of urea in the wine will allow assessment of the dose of urease to be added.

c)        The urease will be eliminated during the filtration of the wine.

d)       The urease shall comply with the prescriptions of the International Oenological Codex.

Recommendation of OIV:

Admitted

II.3.4.12 Lysozyme treatment

Classification :

• Lysozyme: additive

Definition:

Addition of lysozyme to the wine.

Objectives:

a)        Control of the growth and activity of the bacteria responsible for malolactic fermentation of the wine.

b)       Reduction of the rate of sulphur dioxide.

Prescriptions:

a)        According to experiments, the maximum dose of 500 mg/l appears to be sufficient to control the growth and the activity of the bacteria responsible for malolactic fermentation.

b)       Lysozyme cannot totally substitute itself to SO₂ which possesses antioxidant properties. A SO₂ + lysozyme association provides more stable wines.

c)        When must and wine are treated with lysozyme, the cumulative dose must not exceed 500 mg/l.

d)       The product must conform to the prescriptions of the International oenological codex.

Recommendation of the OIV:

Admitted

II.3.4.13 Treatment with dimethyl dicarbonate (DMDC)

Definition:

Addition of dimethyl dicarbonate to wine.

Objectives:

a)        Obtain microbiological stability of bottled wine containing fermentable sugars;

b)       Prevent the development of unwanted yeast and lactic bacteria.

c)        Block fermentation of sweet, medium sweet, and medium dry wines

Prescriptions:

a)        For objective a), should only be added shortly before bottling;

b)       The dosage should be no more than 200 mg/l expressed as dimethyl dicarbonate;

c)        The addition of dimethyl dicarbonate must not lead to surpassing the maximum content level for methanol in wine, as recommended by the OIV.

d)       The wine should not be placed on the market as long as dimethyl dicarbonate is detectable.

e)       The dimethyl dicarbonate used, must comply with the provisions of the International Oenological Codex.

Recommendation of the OIV:

Admitted

II.3.4.14 Adsorbant copolymer treatment (PVI/PVP)

Classification:

• PVI/PVP copolymer: processing aid

Definition:

The addition of polyvinylimidazole – polyvinylpyrrolidone copolymers (PVI/PVP) in order to reduce copper, iron and heavy metal contents.

Objectives:

a)        To prevent defects caused by too high metal contents (for example ferric casse).

b)       To reduce undesirable, high concentration of metals due to:

• Must contaminated by metal cations
• Metal cation contamination during must or wine treatment from winemaking equipment
• Enrichment in copper following the treatment of wines by copper sulphate.

Prescriptions:

a)        The amount used should be less than 500 mg/l.

b)       When musts and wine are treated with PVI/PVP polymers, the accumulated dosage should be less than 500 mg/l.

c)        The copolymers should be eliminated after no more than 2 days after the addition taking into account the precautionary principle and separated from the wine by filtering before bottling

d)       The adsorbant copolymers used should comply with the prescriptions of the International Oenological Codex and in particular monomers limits.

e)       The  implementation of the procedure shall be placed under the responsibility of an oenologist or a specialised technician.

Recommendation of the OIV:

Admitted.

II.3.4.15 Treatment with D,L-Tartaric acid

Classification:

• D,L-tartaric acid: processing aid
• Potassium D,L-tartrate: processing aid

Definition:

Addition of D,L-tartaric acid or the potassium-salts of D,L-tartaric acid in wine

Objectives:

Reduction of excessive levels of calcium

Prescriptions:

a)        The treatment yields particularly insoluble salts. The use of D,L-tartaric acid is subject to certain regulations.

b)       The treatment will be placed under the responsibility of an oenologist or a specialist technician.

c)        The products added shall comply with the prescriptions of the International Oenological Codex.

Recommendation of the OIV:

Admitted

II.3.4.16 Treatment using chitosan

Classification:

• Chitosan: processing aid

Definition:

Addition of chitosan of fungal origin to wines

Objectives:

a)        To reduce heavy metal content, notably iron, lead, cadmium, copper,

b)       To prevent iron haze, copper haze,

c)        To reduce possible contaminants, especially ochratoxin A,

d)       To reduce undesirable micro-organisms, notably Brettanomyces.

Prescriptions:

a)        The doses to be used are determined after preliminary testing. The maximum dose used must not exceed :

• 100 g/hl for the objectives a) and b)
• 500 g/hl for the objective c)
• 10 g/hl for the objective d)

b)       Sediments are eliminated by physical procedures.

c)        Chitosan of fungal origin may be used alone or together with other admitted products.

d)       Chitosan must comply with the requirements of the International Oenological Codex.

Recommendation of the OIV:

Admitted

II.3.4.17 Treatment using chitin-glucan

Classification:

• Chitin-Glucan: processing aid

Definition:

Addition of chitin-glucan of fungal origin to wines

Objectives:

a)        To reduce heavy metal content, notably iron, lead, cadmium, copper,

b)       To prevent iron haze, copper haze,

c)        To reduce possible contaminants, especially ochratoxin A.

Prescriptions:

a)        The doses to be used are determined after preliminary testing. The maximum dose used must not exceed:

• 100 g/hl for the objectives a) and b)
• 500 g/hl for the objective c)

b)       Sediments are eliminated by physical procedures.

c)        Chitin-glucan complex of fungal origin may be used alone or together with other admitted products.

d)       Chitin-glucan complex must comply with the requirements of the International Oenological Codex.

Recommendation of the OIV:

Admitted

II.3.4.18 Treatment with glutathione

Classification:

• Glutathione: Additive

Definition:

Addition of glutathione to wine.

Objectives:

a)        To protect aromatic substances present in wines (and particularly those of the thiol family) from oxidation, thanks to the antioxidant properties of the product;

b)       to limit the formation of compounds responsible for ageing defects resulting from oxidation;

Prescriptions:

a)        The addition of glutathione on storage and/or packaging, including the bottling of wine, is recommended;

b)       the dose used should not exceed 20 mg/L;

c)        the glutathione must be in a reduced form and comply with the prescriptions of the International Oenological Codex.

Recommendation of the OIV:

Admitted

II.3.4.19 Treatment of wines using inactivated yeasts with guaranteed glutathione levels

Classification

• Inactivated yeasts with guaranteed glutathione levels: Processing aid

Definition:

Addition of inactivated yeasts whose cells have guaranteed reduced-glutathione levels.

Objectives:

a)        To limit the oxidation in wines of certain varietal aromatic compounds revealed by the metabolism of yeasts (particularly thiols).

Prescriptions:

a)        The addition of inactivated yeasts with guaranteed glutathione levels at the start of maturing or during storage of wines is recommended;

b)       the dose used of glutathione, supplied directly or via yeasts with guaranteed glutathione levels, should not exceed 20 mg/L, in order to avoid any risk of reduction and the emergence of a yeast taste;

c)        the inactivated yeasts with guaranteed glutathione levels should contain a reduced form of glutathione; this may be accompanied by the presence of its precursors (cysteine and particularly gamma-glutamylcysteine);

d)       the inactivated yeasts with guaranteed glutathione levels should comply with the prescriptions of the International Oenological Codex.

Recommendation of the OIV:

Admitted

II.3.4.20 Use of selective vegetal fibres

Definition:

Use of a selective adsorbent composed of vegetal fibres, during wine filtration.

Objectives:

a)        To reduce the ochratoxin A levels in wines;

b)       to reduce the number and levels of phytosanitary products detected in wines.

Prescriptions:

a)        Selective vegetal fibres are incorporated as processing aids, either during filtration with continuous deposition, or as a constituent of a filter sheet;

b)       the recommended dosage is determined according to the filtration technique used, without exceeding 1.5 kg/m² of the filter sheet surface area;

c)        selective vegetal fibres are used on wines in compliance with regulatory requirements, particularly the permitted residue limits for phytosanitary products;

d)       selective vegetal fibres must comply with the prescriptions of the International Oenological Codex.

Recommendation of OIV:

Admitted

II.3.4.21 Malolactic fermentation activators

Definition:

Addition of malolactic fermentation activators at the end or after the alcoholic fermentation to facilitate malolactic fermentation.

Objective:

Promote the initiation, kinetics or completion of malolactic fermentation:

• by enriching the environment with nutrients and growth factors for acid lactic bacterias,
• by the adsorption of some bacteria inhibitors.

Prescriptions:

a)        Activators are microcrystalline cellulose or products derived from the degradation of yeasts (autolysates, inactivated yeasts, yeast walls);

b)       activators can be added to wine or fermenting wine before or during malolactic fermentation;

c)        the activators do not have to induce to organoleptic deviations in wine

d)       Malolactic fermentation activators must comply with the prescriptions contained in the International Oenological Codex.

Note: The use of malolactic fermentation activators might foster the growth of undesirable microorganisms with the production of undesirable compounds.

Recommendation of the OIV:

Admitted

II.3.4.23 Treatment with fumaric acid to inhibit malolactic fermentation

Classification:

• Fumaric acid : Additive

Definition:

Addition of fumaric acid to wine.

Objective:

a)        Control of the growth and activity of the lactic acid bacteria responsible of the malolactic fermentation of wine;

b)       reduction of the dose of sulphur dioxide;

c)        preserve malic acidity.

Prescriptions:

a)        Doses of 300-600 mg/L to control malolactic fermentation, even in the presence of high quantities of inoculum and during tumultuous fermentation;

b)       fumaric acid must comply with the prescriptions of the International Enological Codex.

Recommendation of the OIV:

Admitted

II.3.5 Preparation for packaging and packaging

II.3.5.1 Fortification

Definition :

Addition to wines of wine spirit, rectified alcohol of viticultural origin or rectified food alcohol.

Objectives :

a)        Increase the actual alcohol content of the wine,

b)       Production of special wines (flor or film wines, fortified wines), mistelles and beverages based on must and/or wine.

Prescription :

The rectified food alcohol, rectified alcohol of viticultural origin or wine spirits shall comply with the production conditions fixed for these products by the present Code and to the prescriptions of the International Oenological Codex. 

Recommendation of OIV:

For objective (a), not admitted

For objective (b), admitted

II.3.5.2 Aromatisation

Definition :

Addition to wine of artificial or natural aromatic substances.

Objective :

To improve aromatic characters of wine or to confer such characters to wines that are devoid of them.

Prescriptions :

The objectives are achieved by addition:

a)        Of natural or artificial flavourings;

b)       Of extracts of natural aromatic substances.

Recommendation of OIV :

Not admitted

II.3.5.4 Hot bottling

Definition:

Bottling of wine heated prior to the immediate corking of the bottle.

Objectives:

a)        Biological stabilisation of the wine;

b)       Elimination of oxygen;

c)        Physico-chemical stabilisation.

Prescription:

The wine should not be heated above 45°C.

Recommendation of the OIV:

Admitted

II.3.5.5 Oxygenation

Classification:

• Oxygen : processing aid

Definition:

Addition of oxygen or air to wine

Objectives:

a)        To use "micro-oxygenation", “macro-oxygenation” and "nano-oxygenation" technologies on wines;

b)       to initiate oxidation phenomena with the aim of:

contributing to stabilisation of colour and maturation of red wines by encouraging in particular the production of acetaldehyde, which can react with flavanols and anthocyanins to cause the formation of new pigments that are more stable and more intensely coloured (hyperchromic and bathochromic effect) than native anthocyanins,

preparing wines used in treatments to eliminate excess iron (file II.3.3.1 ‘Removal of iron’) through oxidation of ferrous iron into ferric iron;

c)        to reduce the concentration of "volatile sulphur compounds" such as hydrogen sulphide, methane-thiol, etc.;

d)       to reduce aroma compounds related to vegetal sensory characters;

e)       to facilitate fining of wines.

Prescriptions:

a)        In the case of “micro-oxygenation”, the rate at which the quantity of oxygen is added should be lower than that of the oxygen consumption by the treated wine; in other words, oxygen should not be accumulated in the wines during treatment. It is preferable to use this technique when wines have a high concentration of free anthocyanins.

b)       “Macro-oxygenation” is defined by the addition of higher doses of oxygen compared to “micro-oxygenation” and by a shorter addition period. This is specifically practiced at the end of fermentation, at a post-fermentative stage and up until the first racking off lees.

c)        In the case of “nano-oxygenation”, oxygen is added at regular intervals in very small quantities, such as 10 to 100 µg oxygen per litre of wine.

d)       In the case of treatment of excess iron (file 3.3.1), oxygenation should be followed by an addition of tannin in proportion to the iron concentration of the wine, followed by fining, preferably with casein. The addition of oxygen should always precede the removal of iron by calcium phytate.

e)       For stabilisation of the colour and improvement of the quality of a red wine during maturation, the doses to be added to the wine, in the case of “micro-oxygenation”, are around 1-5 mg/L per month – depending, mainly, on their initial anythocyanin and polyphenol concentration and concentration of free SO₂. In the case of treatment using “macro-oxygenation”, the oxygen doses added are higher to take into account the oxygen consumption by the yeast lees.

f)         Due to the potential for the development of oxidative aromas, wine that undergoes oxygenation should be tasted regularly in order to define an optimum duration and temperature depending on the desired aromatic profile of the wine. Micro-oxygenation is not recommended above 22 °C to avoid excessive oxidation or below 8 °C to avoid oxygen accumulation.

g)        The aim of oxygenation should not be a reduction in sulphite of wines containing excess sulphur dioxide.

h)       Microbiological stability (especially where Brettanomyces bruxellensis is concerned) should be monitored to avoid organoleptic deviations in wines.

Recommendation of OIV:

Admitted

II.3.5.6 Treatment with caramel

Definition :

Addition of caramel to wine.

Objectives :

a)        To colour the wine.

b)       To modify the taste of the wine.

Recommendation of OIV :

Not admitted

II.3.5.7 Treatment with β-glucanases

Classification:

• Beta-glucanase  (β1-3, β1-6)β: processing aid

Definition :

Addition to wine of an enzyme preparation containing activities catalysing the degradation of beta-glucans produced in the grape berry by the fungus Botrytis cinerea (noble rot, grey rot).

Enzyme activities involved in the degradation of β–glucans of botrytis cinerea are β-glucanases type β-1,3 and 1,6. The β-glucanases including β–1.3-glucanases are also able to degrade β-glucans released by saccharomyces type yeasts during alcoholic fermentation and during wine aging on lees.

Objective :

To improve the clarification and filterability of wines.

Prescription :

The glucanase preparation shall comply with the prescriptions of the International Oenological Codex .

Recommendation of OIV:

Admitted

II.3.5.8 Treatment with copper sulphate

Classification :

• Copper sulphate, pentahydrate : processing aid

Definition :

Addition of copper sulphate pentahydrate (CuSO4 5H2O) to wine

Objective :

To remove the bad taste and odour due to hydrogen sulphide and possibly to its derivatives.

Prescriptions :

a)        The dose of copper sulphate pentahydrate necessary to comply with the objective should be determined by a preliminary test. It shall not exceed 1 g/hl.

b)       The colloidal cupric precipitate formed must be eliminated from the wine.

c)        After treatment, the copper content of the wine should be checked and reduced to a level less than or equal to 1 mg/l by an appropriate procedure, complying with the specifications of Annex C of the Recueil of International Methods of Analysis for Wines and Musts.

d)       The copper sulphate used shall comply with the prescriptions of the International Oenological Codex.

Recommendation of OIV :

Admitted

II.3.5.9 Carbon treatment of slightly coloured wine

Classification :

• Oenological carbon : processing aid

Definition :

Addition of carbon to wine.

Objectives :

Correction of the colour:

• Of white wines produced from red vine varieties with white juice,
• Of white wines accidentally discoloured by contact with containers that have held red wines,
• Of very yellow wines prepared from white varieties,
• Of oxidised wines.

Prescriptions :

a)        The processing shall not:

• Serve to de-colour red wine or rosé,
• Be applied successively to must and to the wine that results from it.

b)       The quantity of dry carbon used shall be less than 100 g/hl of wine.

c)        The carbon used shall comply with the prescriptions of the International Oenological Codex .

Recommendation of OIV:

Admitted

II.3.5.10 In-bottle pasteurisation

Definition :

Heating wine in bottles to a temperature and for a duration sufficient to prevent subsequent activity of microorganisms in the bottle.

Objective :

See 3.4.3

Prescriptions :

a)        Pasteurisation can be performed :

• By immersing bottles in hot water,
• By running hot water onto bottles.

b)       The increase in temperature shall cause no alteration in the appearance, colour, odour or taste of the wine.

c)        A sufficient headspace will be provided under the cork to allow for the expansion in volume of the wine and precautions will be taken to avoid explosion of bottles due to excessive pressure.

Recommendation of the OIV:

Admitted

II.3.5.11.1 Wine concentration by freezing/ Cryoconcentration

Definition:

Prescriptions for concentrating wine by partial freezing and physical removal of the ice thus formed.

Objective:

See the sheet II.3.5.11 “Partial dehydration of wines”.

Prescription:

a)        See the sheet “Partial dehydration of wine”;

b)       Concentration can lead to a reduction of 20% of initial volume and should not be increased by more than 2% by volume of the initial alcohol strength of wine.

Recommendation of the OIV:

Admitted

II.3.5.11.1 Wine concentration by freezing/ Cryoconcentration

Definition:

Prescriptions for concentrating wine by partial freezing and physical removal of the ice thus formed.

Objective:

See the sheet II.3.5.11 “Partial dehydration of wines”.

Prescription:

a)        See the sheet “Partial dehydration of wine”;

b)       Concentration can lead to a reduction of 20% of initial volume and should not be increased by more than 2% by volume of the initial alcohol strength of wine.

Recommendation of the OIV:

Admitted

II.3.5.12 Fermenting must or wines in contact with wood

Definition:

Allow fermenting must or wine to come into contact with wood.

Objective:

Put fermenting must or wine in contact with wood to achieve physical and chemical changes.

Prescriptions:

The objective will be achieved by having the fermenting musts or wines come into contact with wood

Recommendation of the OIV:

Admitted

II.3.5.12.1 Ageing in small capacity wooden containers

Definition:

Ageing of wine in small capacity wooden casks during a set period of time, of a wine suited for an evolution through a natural process, in compliance with the usual practices of each viticulture region.

Objectives:

a)        To obtain a natural evolutionary process of wine, with improvement of its sensory characteristics through an oxidative and/or biological or diffusion pathway, according to usual practices for each wine,

b)       To favour natural physical and chemical mechanisms through the controlled and continuous oxygenation and the progressive contribution of substances released by wood.

c)        To obtain a total or partial physico-chemical stabilisation of the wine.

Prescriptions

a)        It is recommended, in order for the ageing to be efficient, that the volume of the recipient not exceed 600 litres;

b)       The most commonly used botanical species are: Quercus petrea (sissile oak), Quercus robur (pedunculated oak) and their hybrids and Quercus alba (white American oak). Locally, other botanical species than oak may be used. The traceability of wood origin is recommended

c)        For the making of the container, one will only use woods that retain their natural structure. Cooperage techniques defined for the making of new casks will be used to optimise the objectives. The traceability of wood is recommended, and at the very least, the manufacture date should be visibly engraved;

d)       The inside surface of the containers may be regenerated with usual cooperage techniques. In that case, the date on which this is carried out will have to be visibly engraved;

e)       Environmental conditions (temperature, humidity, and isolation) allow for the modulation of oxygen supply to the wine to take place;

f)         During the ageing process, continuous control of the casks’ condition, their level of filling and the degree of modification of the produced sensory characteristics are recommended. The casks are maintained in compliance with hygiene rules and are eliminated after a few years.

Recommendation of the OIV:

Admitted

II.3.5.12.2 Usage of pieces of oak wood in winemaking

Definition:

Usage of pieces of oak wood in winemaking.

Objective:

To introduce the characteristics of certain oak wood constituents into wine.

Prescriptions:

a)        The pieces of wood (from Quercus species) will have to be of an appropriate size.

b)       The pieces of oak wood may be grilled or burnt but not charred, including on the surface.

c)        The quantity of pieces of oak wood to be used in the wine is at the discretion of the winemaker.

d)       The pieces of oak wood shall comply with the prescriptions of the International Oenological Codex.

Recommendation of the OIV:

Admitted

II.3.5.14 Treatment with copper citrate

Classification :

• Copper citrate : processing aid

Definition:

Addition of hydrated copper citrate alone or mixed with clarifying agents (for example bentonite)

Objective:

Remove bad taste and odour due to hydrogen sulfide and possibly its derivatives.

Prescriptions :

a)        The dose of hydrated copper citrate necessary for fulfilling the objective must be determined by a prior trial test. This dose must not exceed 1 g/hl.

b)       Copper colloidal precipitate formed must be eliminated from wine by  filtration

c)        Following all treatments, the copper content of wine must be monitored and returned to levels equal to or under the residual level of wine set by the OIV in accordance with the specifications of Annex C of the International Compendium of Methods of Analysis of Wines and Musts.

d)       The copper citrate used must be in accordance with the provisions of the International oenological Codex.

Recommendation of the O.I.V:

Admitted.

II.3.5.15 Treatment with silver chloride

Definition:

Addition of silver chloride to wine

Objective:

To reduce odour defects due to hydrogen sulphide and some mercaptans.

Prescriptions

a)        The dose used must not be over 1 g/hl

b)       The silver chloride must be previously applied to an inert support, like kieselguhr (diatomaceous earth) or kaolin

c)        The main operation must be preceded by trials to determine the amount of product to add.

d)       The precipitate must be eliminated by any appropriate physical procedure

e)       Residues must be treated by specialised sector

f)         Treated wine must be analysed to insure that the maximal residue level do not exceed 0.1 mg/L in silver

g)        The treatment must  be carried out under the responsibility of an oenologist or a specialised technician

h)       Silver chloride must comply with the provisions of the International Oenological Codex

Recommendation of the OIV:

Admitted

II.3.5.17 Management of dissolved gas in wine using membrane contractors

Definition:

Physical method for the management of dissolved gas concentrations in wine using membrane contactors (hydrophobic membranes) and gases applied in oenology.

Objective:

a)      Reduction of the dissolved oxygen level in wine

b)      Increase of the dissolved oxygen level in wine;

c)      Reduction of the dissolved carbon dioxide level in wine;

d)      Adjustment of the dissolved carbon dioxide level in still or semi-sparkling wines according to the definition in the International Code of Oenological Practices;

e)      Increase of the dissolved carbon dioxide level in order to obtain carbonated wines according to the definition in the International Code of Oenological Practices.

Prescription:

a)      See the general sheet on separative techniques used in the treatment of musts and wines as well as the sheet on the application of membrane techniques in wine.

b)      This technique can be used from the end of alcoholic fermentation to packaging to replace the use of bubbling  device or venturi type systems.

c)      This practice shall be carried out by an oenologist or a qualified technician.

d)      For objective b) see the prescriptions of the resolution related to oxygenation of wine.

e)      The wine treated or to be treated must comply with the definitions and limits of the OIV.

f)      The membranes used must comply with the provisions of the International Oenological Codex.

g)      The gases used must comply with those allowed and defined in the International Oenological Codex.

Recommendation of OIV:

Admitted

II.3.5.18 Treatment of wines using a membrane technology coupled with activated carbon to reduce excess 4-ethylphenol and 4-ethylguaiacol

Definition:

Process that consists of reducing the excess content of 4-ethylphenol and 4-ethylguaiacol in wine using a coupling of technologies combining nanofiltration and treatment with activated carbon deodoriser

Objective:

a)      Reduce the content of 4-ethylphenol and 4-ethylguaiacol of microbial origin that constitutes organoleptic defects and masks the aromas of the wine..

Prescription:

a)      Refer to the general file on separative techniques used in the treatment of wines (Chapter 3.0) and the file on the application of membrane techniques applied to wines (Chapter 3.01).

b)      The objective of the first step of the process is to produce an ultrafiltrate containing some of the volatile phenols. This is achieved through nanofiltration.

c)      The ultrafiltrate obtained during the first step of the process is treated continuously on a column of activated carbon with deodorizing properties, then continuously and fully reincorporated into the initial tank of wine to be treated.

d)      The volume of ultrafiltrate extracted and treated with the column of activated carbon is dependent on the quantity of 4-ethylphenol and 4-ethylguaiacol to be removed.

e)      An oenologist or a qualified technician will be responsible for implementing the treatment.

f)      The activated carbon with deodorizing properties and nanofiltration membranes used must comply with the prescriptions contained in the “International Oenological Codex”.

Recommendation of OIV:

Admitted