II.2.1 Preparation of musts for either preservation or alcoholic fermentation

II.2.1.1 Oxygenation

Classification:

Oxygen: processing aid

Definition:

Addition of oxygen or air to must

Objectives:

a)        To accelerate the oxidation process in musts in white or rosé winemaking with the aim of provoking browning reactions in phenolic compounds, which are formed by polymerisation, then precipitate and are removed during clarification of musts, to improve the stability of wines in relation to oxidation. This practice, which provides for the addition of high levels of oxygen to musts, equivalent to several saturations, is called “hyperoxygenation”;

b)       to contribute to the reduction of aromas compounds related to vegetal sensory character and the disappearance of reductive aromas;

c)        to ensure alcoholic fermentation occurs smoothly and to avoid stuck fermentations.

Prescriptions:

a)        In the case of reduction of the level of phenolic compounds involved in browning phenomena, oxygen should be added before clarification of must;

b)       in the case of management of fermentation kinetics, the addition of oxygen at the recommended dose of 5-10 mg·L^-1 is sufficient provided that this is carried out at the end of the yeast growth phase, namely after the reduction of the sugar concentration of the must by around 50 g·L^-1;

c)        the aim of oxygenation should not be a reduction in sulphite of musts containing excess sulphur dioxide.

Recommendation of OIV:

Admitted

II.2.1.3 Adjustement of acidity of must

II.2.1.3.1.1 Chemical acidification

Classification:

• Malic acid (D,L-, L-): additive
• Lactic acid: additive
• Tartaric 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 viticultural region, or
• oenological practices which lead to a decrease in natural acidity

Prescriptions:

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

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

c)        The addition of mineral acids is forbidden;

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

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

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

When must and wine are acidified, the net cumulative increase must not exceed 54 meq/l (or 4 g/l expressed in tartaric acid),

Recommendation of the OIV:

Admitted

II.2.1.3.1.1.1 Calcium sulfate

Classification:

Calcium sulphate: additive

Definition:

Addition of calcium sulphate (CaSO₄.2H₂0) to the must prior to fermentation in combination with tartaric acid for the elaboration of liqueur wines.

Objective:

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

b)       Favour a good biological evolution and good storage of liqueur wine;

c)        Remedy insufficient natural acidity of liqueur wines caused by:

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

Prescriptions:

a)        The use of calcium sulfate is used in combination with lower tartaric acid level

b)       It is suggested to make laboratory preliminary tests to calculate the doses of calcium sulfate and tartaric acid needed to reduce the pH required;

c)        The dose must not exceed 2 g/L of calcium sulfate because it allows to reach the adequate pH 3.2 in the winemaking of these musts and to obtain equilibrated wines even in years of adverse weather conditions;

d)       The residual level of sulfates in wines must not exceed the OIV limit;

e)       The practice should not be done to conceal fraud;

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

g)        Calcium sulfate used must comply with the prescription of the International Oenological Codex standards.

Recommendation of the OIV:

Admitted only for liqueur wines

II.2.1.3.1.2 Microbiological acidification

Definition:

Increase of titratable acidity and real acidity (decrease in pH) by using yeasts.

Objective:

a)        see general sheet “acidification” (II.2.1.3.1)

Prescriptions:

In order to achieve this objective, microbiological acidification by yeasts may be carried out by inoculation of selected strains.

Recommendation of the OIV.:

See sheet: acidification by yeasts (Saccharomyces and non-Saccharomyces)( II.2.1.3.1.2.1)

II.2.1.3.1.2.1 Acidification by yeasts

Definition:

Increase of titration acidity and real acidity (decrease in pH) during alcoholic fermentation with yeasts (Saccharomyces and non-Saccharomyces)”.

Objectives:

a)        To make balanced wine from a sensory point of view;

b)       To obtain a production of D or L-malic acid and/or D or L-lactic and/or succinic acid during alcoholic fermentation.

Prescriptions:

Acidification by musts can operate:

a)        on musts (see file II.2.1.3.1);

b)       with pure strains or successive fermentations using yeast strains capable of producing D or L-malic acid and/or D or L-lactic and/or succinic;

c)        the yeast must comply with the prescriptions of the International Oenological Codex.

Recommendation of the OIV:

Admitted.

II.2.1.3.1.3 Acidification by electromembrane treatment (bipolar membrane electrodialyse)

Definition:

Physical ionic must extraction method under action of electric field using permeable cation membranes and bipolar membrane giving rise to increased titratable acidity and actual acidity (decrease in pH).

Objectives:

a)        Increase titration acidity and actual acidity (decrease in pH).

b)       Promote good biological characteristics and favour good vinification.

c)        Favour good maturation of 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 on separative techniques used in the treatment of musts and wines and the sheet concerning 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 a way so as to only enable them to be adapted to the extraction of cations only and in particular cations: K+.

d)       Bipolar membranes are impermeable to anions and cations of musts.

e)       Acidification by bipolar electrodialysis must only be carried out provided that initial must acidity is not increased more than 54 meq/l (that being 4 g/l expressed in tartaric acid).When musts and wine are acidified, the net accumulated increase must not be over 54 meq/l (that being 4 g/l expressed in tartaric acid).

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.2.1.3.1.4 Acidification by cation exchanger treatment

Definition:

Physical partial extraction of cations of the musts to increase titration acidity and actual acidity (decrease in pH). through a cation exchanger.

Objectives:

a)        Increase titration acidity and actual acidity (decrease in pH)

b)       Refer to the objectives in the general file II.2.1.3.1 Acidification

Prescriptions:

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

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

c)        To avoid the production of fractions of must, the treatment will be performed continuously, with in-line incorporation of the treated must into the original must.

d)       As an alternative, the resin could be directly introduced into the tank of must, in the quantities required, then separated by all appropriate technical methods.

e)       The acidification must be carried under condition that the initial acidity is not raised by more than 54 meq/L. When must and wine are acidified, the cumulative net increase must not exceed 54 meq/L

f)         All operations will be placed under the responsibility of an oenologist or qualified technician

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

Recommendation of the OIV:

Admitted

II.2.1.3.2.2 Chemical de-acidification

Classification :

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

Definition:

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

Objectives :

a)       See II.2.1.3.2 ‘De-acidification’

b)       To favour biological de-acidification.

Prescriptions :

a)        The wine produced from a de-acidified must shall contain at least 1 g/l tartaric acid;

b)       The process of the formation of the double salt (neutral calcium salts of tartaric and malic acids) should be applied in the case of musts very rich in malic acid for which precipitation of the tartaric acid alone does not provide a satisfactory reduction of the titratable acidity,

c)        The aim of chemical de-acidification shall not be to conceal fraud,

d)       Chemical de-acidification and chemical acidification are mutually exclusive.

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

Recommendation of OIV:

Admitted

II.2.1.3.2.3 Microbiological de-acidification

Definition:

Lowering of total acidity and real acidity (increase in pH) by using yeasts or lactic acid bacteria.

Objective:

See sheet II.2.1.3.2 De-acidification

Prescriptions:

In order to achieve this objective, microbiological de-acidification by microorganisms is carried out by inoculation of selected strains.

Recommendation of the OIV:

See sheets:

• II.2.1.3.2.3.1 ‘De-acidification by yeasts (Saccharomyces and non-Saccharomyces)’ and / or
• II.2.1.3.2.3.2 ‘De-acidification by lactic acid bacteria’.

II.2.1.3.2.3.1 De-acidification by yeasts

Definition:

Lowering of total acidity and real acidity (increase in pH) by using selected yeasts (Saccharomyces and non-Saccharomyces)

Objectives:

a)        To make balanced wine from a gustatory sensation point of view;

b)       To obtain a partial or total breakdown of malic acid by a biological pathway

Prescriptions:

Biological decrease of malic acid by yeasts can operate:

a)        On musts (see file II.2.1.3.2.3 ‘Microbiological de-acodification’);

b)       The objective under b) can be achieved during alcoholic fermentation using selected Saccharomyces or non-Saccharomyces strains. Strains of Saccharomyces genus are known for their partial breakdown capabilities. Strains of Schizosaccharomyces pombe are known for their total malic acid breakdown capabilities;

c)        The use of Schizosaccharomyces yeasts has shown its efficiency for obtaining a rapid breakdown, whether partial or complete, of L-malic acid in musts and wines. Due to the great decrease of titratable acidity and the concentration of hydrogen ions, induced by the activity of these yeasts, their development can be undesirable for certain wines. So precautions should be taken to avoid contamination of the vats for which the development of these yeasts is undesirable.

d)       Yeasts must comply with the prescriptions of the International Oenological Codex.

Recommendation of the OIV:

Admitted.

II.2.1.3.2.3.2 De-acidification by lactic acid bacteria

Definition:

Reduction of the total acidity and real acidity (increase in pH) through the use of lactic acid bacteria of the Lactobacillus, Leuconostoc, Pediococcus and Oenococcus genera.

Objectives:

a)        To develop balanced wines in terms of taste sensations;

b)       to obtain the total or partial degradation of malic acid by biological means.

Prescriptions:

a)        To achieve the objective, de-acidification by lactic acid bacteria is conducted by addition of at least 10⁶ CFU/mL of selected strains of lactic acid bacteria to must, which may or may not be in the process of alcoholic fermentation.

b)       the selected strains must comply with the prescriptions of the International Oenological Codex.

OIV recommendation:

Admitted

II.2.1.3.2.4 De-acidification using an electromembrane process

Definition:

Physical method of ionic extraction from the must 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 bipolar 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

c)        Promote a smooth wine maturing operation

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 musts.

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

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

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

e)       The wine from a de-acidified must should contain at least 1g/L^-1 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”

OIV recommendation:

Admitted

II.2.1.3.2.5 Treatment with potassium carbonate

Classification:

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

Definition:

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

Objective:

a)       See II.2.1.3.2 ‘De-acidification’

b)       For de-acidification of must.

Prescriptions:

a)        The wine produced from a de-acidified must should contain at least 1 g/l tartaric acid for wine quality reasons;

b)       The process of the formation of the double salt (neutral calcium salts of tartaric and malic acids) should be applied in the case of musts very rich in malic acid for which precipitation of the tartaric acid alone does not provide a satisfactory reduction of the titratable acidity;

c)        The aim of chemical de-acidification shall not be to conceal fraud;

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

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

Recommendation of OIV:

Admitted

II.2.1.4 Use of enzymes for the clarification

Classification:

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

Definition :

Addition to must of enzymatic preparations containing activities catalysing the degradation of grape macromolecules which went into the must during the juice extraction operations, as well as beta-glucans produced by the fungus Botrytis cinerea.

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

Objective:

To facilitate the clarification of musts.

Prescription:

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

Recommendation of OIV:

Admitted

II.2.1.5 Settling

Definition :

Separation, before fermentation, of the more or less clear liquid from the solid matter suspended in the must.

Objectives :

a)        To eliminate soil particles.

b)       To eliminate organic particles so as to reduce phenoloxidase activity.

c)        To reduce the indigenous microbial flora.

d)       To reduce colloid content and turbidity.

Prescriptions :

a)        To achieve these objectives, one can use :

• Static settling, either spontaneously or facilitated by the use of appropriate additives, consisting of leaving the must for a few hours in a tank, then separating the deposit by decanting.
• Dynamic settling by centrifugation or filtration.

b)       To avoid the commencement of fermentation, the must may be initially cooled and/or sulphited.

Recommendation of OIV:

Admitted

II.2.1.6 Gelatin treatment

Classification

• Gelatin: processing aid

Definition:

Addition of gelatin to the must

Objectives:

a)        Reduction of polyphenolic compounds in the must, in order to decrease must astringency before fermentation.

b)       Reduction of the particles which are insoluble in the must.

Prescription:

This gelatin must conform to the prescriptions of the International oenological codex.

Recommendation of the OIV:

Admitted

 II.2.1.7 Tanin addition

Definition :

Addition of tannin to must.

Objectives :

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

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

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

d)       to promote the expression of colour in red wines obtained from musts to which tannins have been added.

Prescription :

a)        To facilitate rapid incorporation into must, tannins may be added immediately after harvesting;

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

Recommendation of the OIV:

Admitted

II.2.1.8 Treatment with bentonites

Classification:

• Bentonites : processing aid

Definition :

Addition of bentonites to must.

Objective :

Preventive treatment for protein and copper hazes.

Prescription :

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

Recommendation of OIV:

Admitted

II.2.1.9 Treatment with carbon

Classification:

• Oenological carbon: processing aid

Definition :

Addition of carbon to musts.

Objectives :

a)        To correct organoleptic characteristics of wine coming from musts affected by fungi such as grey rot or oidium;

b)       To eliminate possible contaminants;

c)        To correct the colour :

• white musts derived from the white juice of red grapes,
• very yellow musts derived from white grape varieties,
• oxidized musts.

Prescriptions :

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

b)       The carbon added shall comply with the prescriptions of the International Oenological Codex.

Recommendation of OIV:

Admitted

II.2.1.10 Treatment with silicon dioxide

Classification

• Colloidal solution of silicon dioxide: Processing aid

Definition :

Addition to must of a colloidal solution of silicon dioxide coupled with the addition of a gelatin solution.

Objective :

To achieve the flocculation of the gelatin with a view to clarification.

Prescriptions :

a)        The product is added to the must.

b)       Preliminary tests are necessary to determine optimal doses of colloidal silicon dioxide and of gelatin.

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

Recommendation of OIV:

Admitted

II.2.1.11 Filtration

Definition :

Physical process by which must is passed through appropriate filters that retain particles in suspension.

Objective :

Clarification of the must.

Prescriptions :

a)        Filtration is practised with or without additives.

b)       Additives used, such as diatomaceous earth and cellulose paste and powder, shall comply with the prescriptions of the International Oenological Codex

Recommendation of OIV:

Refer to the practices and treatments mentioned above.

II.2.1.11.1 Filtration on a filter bed

Classification:

• Diatomite: processing aid
• Perlite : processing aid

Definition :

Filtration of the must through a bed of auxiliary filter material.

Objective :

See II.2.1.11 ‘Filtration’

Prescriptions :

The filtration can be undertaken :

a)        By continuous deposition of the bed on appropriate supports;

b)       On a filter bed formed on a rotary drum under vacuum with continuous elimination of the external skin containing the filtered particles.

Auxiliary filter materials, such as diatomaceous earth, perlite and cellulose, are chosen as a function of the degree of clarification desired. They shall comply with the prescriptions of the International Oenological Codex.

Recommendation of the OIV:

Admitted

II.2.1.12 Partial dehydratation of musts

Definition:

Process consisting in the elimination of a certain quantity of water in grape must.

Objectives:

a)        To increase the sugar level of a must intended to be fermented;

b)       To produce caramelized musts;

c)        To produce concentrated musts;

d)       To prepare grape sugar.

Prescritions:

a)        The objectives can be reached by various techniques called subtractive richness techniques:

• cold concentration;
• Inverse osmosis
• Partial evaporation by vacuum;
• Partial evaporation by atmospheric pressure;

b)       For objective under a), concentration cannot lead to a reduction of more than 20% of initial volume nor increase more than 2% of the initial, potential alcoholic strength of the must.

c)        The elimination of water in the must cannot be cumulated with the elimination of water in the corresponding wine (only for objective a).

Recommendations of the OIV:

To refer to the sheets concerning the above-mentioned practices and treatments.

II.2.1.12.1 Concentration

Definition :

Process consisting of concentrating must by elimination of part of the water through specific membranes under the action of a pressure greater than the osmotic pressure of the must.

Objective :

To obtain an enrichment of the must, especially in sugars.

Prescriptions :

a)        The concentration can be performed on all or part of the must.

b)       The concentration shall not be undertaken to reduce the initial volume of the must by more than 20% nor to increase the initial potential alcohol content of the must by more than 2% (vol.).

c)        Since this procedure entails a concentration of all must constituents, its application shall be limited to musts where its use is justified.  It should not be used to modify the type of wine produced.

d)       The procedure shall be conducted under the responsibility of an oenologist or a specialist technician.

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

Recommendation of OIV

Admitted

II.2.1.12.2 Partial evaporation

Definition:

Prescriptions to concentrate musts at a moderate temperature by evaporation of a portion of the water in the thermal exchanger under a high vacuum.

Objective:

See the sheet on II.2.1.12 “Partial dehydration of musts”.

Prescriptions:

a)        Select a continuous, rather than a re-circulating, unit;

b)       The prescription concentrates all ingredients and should thus be limited to must justifying this technique and should not modify the type of wine produced;

c)        This prescription is not recommended for musts from grape varieties with significant free varieties of odour;

d)       A volume counter will measure the amount of water eliminated.

Recommendation of OIV:

Admitted

II.2.1.12.3 Partial evaporation under atmospheric pressure

Definition:

Process consisting in eliminating a certain quantity of water from grape must in an evaporational system under atmospheric pressure.

Objectives:

See II.2.1.12. b, c, and d ‘Partial dehydratation of musts’

Prescriptions:

a)        Evaporation may be done in open cauldrons, with or without stirring, heated:

• by direct fire, or
• by steam sleeves or in another calorific fluid

b)       These processes must be conducted in such a way as to obtain the desired degree of concentration and caramelization of sugar without obtaining undesirable changes in taste.

Recommendation of the OIV:

Admitted

II.2.1.12.4 Concentration of must by cold

Definition:

Process consisting in concentrating must by partial freezing and elimination of the ice thus formed.

Objective:

See II.2.1.12 a and c ‘Partial dehydratation of musts’

Prescriptions:

A light sulfiting of the must before freezing is recommended.

Recommendation of the OIV:

Admitted

II.2.1.13 Desulphiting

Definition :

Operation designed to remove from the must, completely or partially, the sulphur dioxide that had been introduced by sulphiting.

Objectives :

a)        To render the must suitable for the production of different products, notably concentrated must, grape juice and special wines.

b)       To render fermentable a must preserved with sulphur dioxide.

Prescription :

Only physical processes may be employed.

Recommendation of OIV:

Admitted

II.2.1.14 Flotation

Definition:

An operation consisting of injecting gas into a must in such a way as to cause particles or microorganisms to rise to its surface.

Objectives:

a)        Obtain rapid clarification with or without adding clarifying agents;

b)       Reduce the indigenous population of microorganisms prior to alcoholic fermentation for the subsequent use of selected yeasts;

c)        To continuously clarify in order to regularize the quantity of items to eliminate;

d)       And possibly, enhance oxygenation during clarification.

Prescriptions:

Clarification can be done:

a)        Protected from air by using nitrogen or carbon dioxide, or by aerating to encourage the oxidation of oxidable compounds and render the color of the wine more stable by aeration;

b)       At ambient temperature, after chilling or by using continuous systems which allow real-time control of clarifying agents and clarification speed;

c)        Or in a static manner using appropriate containers

d)       The products used must conform to the International Oenological Codex standards

Recommendation of the OIV:

Admitted

II.2.1.15 Treatment with potassium caseinate

Classification :

• Potassium caseinate: processing aid

Definition:

Addition of potassium caseinate to musts in the form of a colloidal suspension or in association with other fining agents.

Objective:

Eliminate oxidized polyphenolic compounds or those compounds likely to oxidize

Prescription:

Potassium caseinate must comply with prescriptions of the International Oenological Codex.

Recommendation of the OIV:

Admitted

II.2.1.16 Treatment with casein

Classification :

• Casein (calcium caseinate): processing aid

Definition:

Addition of casein to musts in the form of a colloidal suspension or in association with other fining products.

Objective:

Elimination of polyphenolic compounds or those susceptible to oxidation

Prescription:

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

Recommendation of the OIV:

Admitted

II.2.1.17 Fining using proteins of plant origin

Objectives

Use of protein matter of plant origin for the fining of musts in order to improve their clarity, stability and taste.

Prescriptions:

a)        The dose to be used is determined after a preliminary test trial. The maximum usage dose should be less than 50 g/hl. The dose retained corresponds to the sample which produces the sought after clarity and gives a better result for tasting.

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

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

Recommendation of the OIV:

Admitted

II.2.1.18 Use of enzymes for improving the filterability

Classification:

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

Definition:

Addition to must of enzymatic preparations containing activities catalysing the degradation of plugging macromolecules of grapes which went into the must during the juice extraction operations.

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

Objective:

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

Prescription:

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

Recommendation of the OIV:

Admitted

II.2.1.19 Use of enzymes for the release of flavouring substances

Classification:

• Glycosidases: processing aid
• Glucosidases: processing aid

Definition:

Addition to must of enzymatic preparations containing activities catalysing the hydrolysis of the saccharide portion of the glycosylated aromatic substances (flavour precursors) of the grape, such as glycosylated terpenes.

Enzyme activities involved in the release of flavouring substances are glycosidases and glucosidases. Depending on the degree of inhibition by glucose, these enzymes may become active only after the fermentation has concluded.

Objective:

to enhance the aromatic potential of the must.

Prescription:

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

Recommendation of the OIV:

Admitted

II.2.1.20 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 (for example by residues from phytosanitary products containing copper),
• Metal cation contamination during must treatment from winemaking equipment.

Prescriptions:

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

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

c)        The copolymers should be eliminated by filtration no later than two days after the addition taking into account the precautionary principle. In the case of cloudy musts, the copolymer must be added no earlier than a maximum of two days before filtration.

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.2.1.21 Treatment with D,L-Tartaric acid

Classification:

• D,L-tartaric acid: processing aid

Definition:

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

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.2.1.22 Fining using chitosan

Classification:

• Chitosan: processing aid

Definition:

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

Objectives:

• To facilitate settling and clarification
• To carry out a treatment to prevent protein haze

Prescriptions:

a)        The doses to be used are determined after preliminary testing. The recommended dose used should be less than or equal to 100 g/hl.

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

Recommendation of the OIV

Admitted

II.2.1.23 Fining using chitin-glucan

Classification:

• chitin-glucan: processing aid

Definition:

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

Objectives:

a)        To facilitate settling and clarification

b)       To carry out a treatment to prevent protein haze

Prescriptions:

a)        The doses to be used are determined after preliminary testing. The recommended dose used should be less than or equal to 100 g/hl.

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

Recommendation of the OIV

Admitted

II.2.1.24 Fining using yeast protein extracts

Classification :

• Yeast protein extracts: processing aid

Definition:

Addition of yeast protein extracts for fining musts

Objectives:

a)        Facilitate racking of musts

b)       Reduce turbidity of musts by precipitating suspended particles

c)        Reduce quantity of tannin

d)       Improve filtrability of wine derived from fined musts

Prescriptions:

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

b)       Maximum dose to be used, determined by a test of efficiency in laboratory must not exceed 30 g/hl

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

d)       The deposits from the fining of musts are eliminated from the musts by physical processes

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

Recommendation of the OIV:

Admitted

II.2.1.25.1 Reduction of the sugar content in musts through membrane coupling

Definition:

Process that consists in extracting the sugar from musts, by using membrane coupling combining microfiltration or ultrafiltration with nanofiltration or inverted osmosis.

Objectives:

a)        Reducing the sugar content of musts destined for fermentation, with the purpose of obtaining a wine with reduced ethanol content;

Prescriptions:

a)        Refer to the general sheet concerning the reduction of sugar content in musts (sheet II.2.1.25 ‘Reduction of the sugar content in musts Fining using yeast protein extracts’)

b)       The treatment is carried out on a volume of must that is determined according to the required result in terms of sugar content reduction.

c)        The objective of the first step is to prepare the must for the second concentration step and to filter out all the macromolecules smaller than the membrane’s cut-off size.  This step may be done by ultrafiltration.

d)       The ultrafiltrate obtained during the first step of the treatment is then concentrated by nanofiltration or inverted osmosis. The water and the organic acids filtered out by the nanofiltration process can be reintroduced into the treated must

e)       The treatment is to be conducted under the responsibility of an oenologist or of a qualified technician

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

Recommendation of the OIV:

Admitted

II.2.1.16 Treatment by discontinuous high pressure processes

Definition:

Process that consists in the reduction of indigenous organisms in musts by the use of discontinuous high pressure processes, with pressures higher than 150 MPa (1500 bar).

Objective

a)        To reduce the microbial loads of indigenous microorganisms, especially yeasts,

b)       To reduce SO2 levels used in winemaking,

c)        To accelerate maceration in red winemaking.

Prescriptions

a)        The high hydrostatic pressure (HHP) technique relates to the use of pressure levels of higher than 150 MPa (1500 bar) during a discontinuous process.

b)       The elimination of yeasts in grapes and musts requires pressure levels of 200-400 MPa.

c)        The elimination of bacterial cells needs pressure levels of 500-600 MPa.

d)       The treatment time range is 2-10 minutes.

e)       If necessary, the increase in temperature may be controlled by supplementary refrigeration.

f)         The increase in temperature and the techniques used should not entail any alteration in the appearance, colour, flavour or taste of the wine.

Recommendation of OIV

Admitted

II.2.1.27 Treatment of grapes by pulsed electric fields

Definition:

A process that consists on the application of sufficiently high pulsed electric fields (PEF) to destemmed and crushed grapes that causes the permeabilization of the cell membranes especially of the grape skins.

Objective

a)        Treatment of red grapes destemmed and crushed by PEF in order to

• Facilitate and increase the extraction of valuable substances such as polyphenols, yeast available nitrogen, aroma compounds including precursors, and other substances located inside the grape cells
• Reduce maceration time

b)       Treatment of white grapes destemmed and crushed by PEF in order to

• Facilitate and increase the extraction of valuable substances such as yeast available nitrogen, aroma compounds including precursors, and other substances located inside the grape cells.

Prescriptions

The technique consists on the application of pulsed electric fields in the range of nanoseconds to milliseconds which are sufficiently high to permeabilize the cell membranes. The destemmed and crushed grapes are treated in at least one treatment chamber with at least one pair of electrodes.

Recommendation of OIV

Admitted

II.2.2 Preservation of musts

II.2.2.1 Treatment with sorbic acid

Definition:

Addition of sorbic acid or potassium sorbate to must.

Objective:

To prevent the alcoholic fermentation of the must.

Recommendation of OIV:

Not admitted.

II.2.2.2 Preservation with alcohol before or during fermentation

Definition:

Addition of rectified alcohol of viticultural origin, wine spirit, alcohol of viticultural origin or rectified food alcohol to the must before or during alcoholic fermentation.

Objectives:

a)        To prevent alcoholic fermentation of a must with a view to producing either a mistelle (see Part I, chap. 5 Mistelles), or a must preserved with alcohol

b)       To stop alcoholic fermentation with a view to obtaining a fortified wine (see Part I, chap. 4.3 Fortified wines).

Prescriptions:

a)        Spirits of viticultural origin shall comply with the prescriptions of the International Oenological Codex and shall conform to the production conditions for these products specified in the present Code.

b)       The nature of the alcohols and spirits added depends on the final product to be produced (see the sections corresponding to the different products).

Recommendation of OIV:

Admitted

II.2.2.3 Preservation by addition of carbon dioxide to must or carbonation of must

Definition:

Addition of carbon dioxide under pressure to must, so as to hinder its fermentation.

Objectives :

a)        Preservation of must destined for the manufacture of juice.

b)       Slowing or stopping fermentation without other intervention.

Prescription :

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

Recommendation of OIV:

Admitted

II.2.2.4 Pasteurisation

Definition :

Heating must to a specified temperature for a given time.

Objectives :

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

b)       To inactivate enzymes present in the must.

Prescriptions :

a)        Pasteurisation is performed in bulk by passing the must through a heat exchanger followed by rapid cooling.

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

Recommendation of OIV:

Admitted

II.2.2.5 Protection under inert atmosphere

Classification:

• Nitrogen : processing aid
• Argon : processing aid

Definition :

Operation consistent with creating an inert atmosphere using nitrogen, carbon dioxide and/or argon.

Objective:

To keep the must protected from air to avoid oxidation and the growth of aerobic organisms.

Prescriptions :

The nitrogen, carbon dioxide and argon shall comply with the prescriptions of the International Oenological Codex.

Recommendation of OIV:

Admitted

II.2.2.6 Lysozyme treatment

Classification

• Lysozyme: Processing aid

Definition:

Addition of lysozyme to the must.

Objectives:

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

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 during alcoholic 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 accumulated dose must not exceed 500mg/l.

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

Recommendation of the OIV:

Admitted

II.2.2.7 Treatment with ascorbic acid

Classification:

• Ascorbic acid: additive
• Erythorbic acid: additive

Definition:

Addition of ascorbic acid to must.

Objectives:

a)        Protect the aromatic substances of the grape, through the antioxidant properties of the product, against the influence of oxygen in the air.

b)       Limit the formation of ethanal during alcoholic fermentation, through the combination with sulphur dioxide.

c)        Limit the formation of hydrogen sulphide and volatile thiols of fermentation origin.

Prescriptions:

a)        It is recommended to add ascorbic acid immediately after the grape’s crushing.

b)       The dose used, cumulated if necessary, with that used on the grapes, shall not exceed 250 mg/l.

c)        It is advisable to use ascorbic acid with sulphur dioxide.

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

Recommendation of OIV:

Admitted

II.2.2.8 Treatment of must with glutathione

Classification:

• Glutathione: additive

Definition:

Addition of glutathione to musts.

Objective:

To limit the intensity of oxidation phenomena in musts, thanks to the ability of glutathione to trap quinones and reduce their oxidative activity.

Prescriptions:

a)        It is advised to add the glutathione while obtaining the musts or at the start of alcoholic fermentation, ensuring that, prior to and during alcoholic fermentation, the assimilable nitrogen level is sufficient to avoid the metabolism of glutathione by the yeast;

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.

OIV recommendation:

Admitted

II.2.2.9 Treatment using inactivated yeasts with guaranteed glutathione levels

Classification:

inactivated yeasts with guaranteed glutathione levels: processing aids

Definition:

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

Objectives:

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

b)       to promote yeast metabolism through the provision of naturally-occurring nutritional compounds.

Prescriptions:

a)        The addition of inactivated yeasts with guaranteed glutathione levels at the start or during the alcoholic fermentation is recommended, ensuring that the assimilable nitrogen level is sufficient to avoid the use of glutathione by the fermentative yeasts;

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.2.2.10 Treatment by continuous high pressure processes

Definition:

Operation for the elimination of wild microorganisms in musts by high pressure processing (above 200 MPa or 2000 bar) in continuous. In UHPH, the pressure is usually ranging 300-400 MPa.

Objectives:

• To reduce or eliminate the load of wild microorganisms, mainly yeasts, preserving the organoleptic quality.
• To reduce the amount of SO2 used in winemaking.
• To reduce or inactivate the activity of oxidative enzymes.
• To get grape must stable from the microbiological point of view.
• To obtain partially fermented musts.

Prescriptions:

a)        The ultra high pressure homogenization technique (UHPH) consists in the application of pressures higher than 200 Mpa (2000 bar) by continuous pumping.

• UHPH: continuous process that could be better integrated in the pretreatment of musts.

b)       To eliminate the yeasts of the musts, pressures of 200-400 Mpa are needed.

c)        To eliminate bacteria, pressures of 200-400 Mpa are needed.

d)       The treatment speed can range from 40 L / h to 40,000 L / h.

e)       If necessary, the increase in temperature can be controlled with additional refrigeration.

f)         Neither the increase in temperature nor the techniques used should produce significant alterations in the appearance, color, smell or taste of the wine.

g)        The procedures must conform to the specifications of the International Oenological Codex.

Recommendation of the OIV:

Admitted

II.2.2.11 Treatment of musts using adsorbent styrene-divinylbenzene beads

Definition:

Physical process of reduction or elimination of organoleptic deviations characterised as “earthy-musty” by the appropriate and controlled percolation of musts at a high flow rate through adsorbent styrene-divinylbenzene beads.

Objectives:

a)        To eliminate the perception of organoleptic deviations characterised as “earthy-musty” by the reduction in concentration or elimination of one of the main molecules responsible, geosmine.

Prescriptions:

a)        Treatment should be carried out on clarified musts with turbidities of less than 30 NTU (nephelometric turbidity units). With regard to red grapes, a preliminary treatment separating the liquid phase from the solid parts should be envisaged.

b)       The quantity of adsorbent beads to be used in the column and the must flow rate are to be determined based on the initial geosmine content.

c)        The adsorbent beads are placed in a column that is compliant with standards for food contact materials.

d)       The adsorbent beads implanted and the condition of their use should comply with the prescriptions of the International Oenological Codex.

Recommendation of the OIV:

Admitted

II.2.2.12 Use of Aspergillopepsin I to remove haze-forming proteins

Definition:

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

Objectives:

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

Prescriptions:

a)        Addition of Aspergillopepsin I preparation to must prior to initiation of fermentation

b)       After addition of Aspergillopepsin I preparation, one short-term must 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 Aspergillopepsin I preparation as regards the 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.

c)        The must is cooled to an appropriate temperature prior to yeast inoculation.

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

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

Recommendation of the OIV:

Admitted

II.2.3 Alcoholic fermentation

Definition:

Transformation of grape sugars into ethanol, carbon dioxide and secondary products.

Objective :

Production of wine.

Prescriptions :

a)        Fermentation can take place:

• Spontaneously by means of yeasts naturally present on the skins of the grapes, in the musts and in cellars ;
• By inoculation of must or of crushed grapes with selected yeasts, before or during the fermentation (see II.2.3.1 ‘Inoculation with yeasts’). 

b)       The progress of the alcoholic fermentation can be influenced:

• By addition of activator substances (see Activation of alcoholic fermentationII.2.3.2 and II.2.3.4 ‘Treatment with yeast ghosts’):
• By aeration of the crushed grapes or of the fermenting must (see Aeration II.2.3.5);
• By control of the fermentation temperature as a function of the type of wine desired (see II.2.3.6 ‘Interruption of alcoholic fermentation by physical processes’);
• By all other acceptable interventions aiming to favour alcoholic fermentation, to restrain it or to stop it.

Recommendation of OIV:

Admitted

II.2.3.1 Inoculation with yeasts

Definition :

Inoculation of a must, before or during its fermentation, with the help of a starter inoculum prepared either from indigenous yeasts or from selected yeasts.

Objectives :

a)        To initiate, regulate and accelerate fermentation, especially in the case of vinifications, which are proceeding too slowly.

b)       To re-activate an interrupted fermentation.

c)        To facilitate the depletion of glucose and fructose.

d)       To change the wine acidity by synthesis or breakdown of organic acids.

e)       To produce less volatile acidity, especially in the case of musts with high sugar levels.

f)         To impact on the wine’s sensorial properties (aromas, mouthfeel).

Prescriptions :

a)        Use the yeast or mixture of yeasts appropriate for the objective pursued. Use the yeast appropriate to the objective pursued.

b)       In the case of non-Saccharomyces, the addition occurs before or at the same time as for the Saccharomyces.

c)        The commercial starters added may be pure cultures or blends of Saccharomyces strains and non-Saccharomyces strains.

d)       Where active, selected yeasts (Saccharomyces and non-Saccharomyces) are used, these shall comply with the prescriptions of the International Oenological Codex.

Recommendation of OIV:

Admitted

II.2.3.2 Fermentation activators

Classification:

• Yeast auto lysates: processing aid
• Microcrystalline Cellulose: processing aid
• food-grade cellulose: processing aid
• Inactivated yeasts: processing aid
• Fatty acid mono- and diglycerides: processing aid

Definition:

Addition to the harvest or the must, before or during the alcoholic fermentation, of fermentation activators.

Objective:

Favour the beginning or the completion of alcoholic fermentation;

a)        By enriching the environment with nutritive elements (ammoniacal nitrogen, aminated and peptidic nitrogen) and growth factors (thiamine, long chain fat acids),

b)       In detoxifying the environment by rapid release of carbon dioxide at the start of alcoholic fermentation and/or by adsorption of yeast inhibitors such as medium chain fat acids (supporting role of inactivated yeasts, food-grade cellulose).

Prescriptions :

a)        The activators can be microcrystalline cellulose, food-grade cellulose, ammoniacal salts, thiamine or products coming from the degradation of yeasts (autolysates, cell skins, inactivated yeasts).

b)       Fermentation activators must conform to the prescription of the International oenological codex.

Recommendation of the OIV:

Admitted

II.2.3.3 Treatment with thiamin

Classification:

• Thiamine hydrochloride: processing aid

Definition :

Addition of thiamin to must.

Objectives :

a)        To accelerate the alcoholic fermentation.

b)       To reduce the formation, during the alcoholic fermentation, of substances capable of combining with sulphur dioxide and also to allow a reduction in the dose.

Prescriptions :

a)        According to experiments conducted to date, a dose of 60 mg/hl proves sufficient.

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

Recommendation of the OIV :

Admitted

II.2.3.4 Treatment with yeast ghosts

Classification :

• Yeast hulls: processing aid

Definition :

Addition to the must, to the fermenting must or to the wine of a preparation of yeast ghosts.

Objectives :

a)        To prevent sticking of the alcoholic fermentation

b)       To facilitate the completion of slow fermentations.

c)        To treat “stuck” fermentations.

Prescriptions :

a)        Yeast ghosts are added before or at the start of fermentation for objective (a); at the end of the fermentation for objective (b); before the yeast inoculation for objective (c).

b)       The doses used shall not be greater than 40 g/hl.

c)        The yeast ghosts shall comply with the prescriptions of the International Oenological Codex

Recommendation:

Admitted

II.2.3.6 Interruption of alcoholic fermentation by physical procedures

Definition :

Arresting the alcoholic fermentation.

Objective :

To obtain a product containing endogenous sugar.

Prescriptions :

a)        Only the physical techniques: heat, cold, filtration and centrifugation may be used.

b)       The product obtained shall remain fermentable.

Recommendation of OIV:

Admitted

II.2.3.8 Fermentation in small capacity wooden containers

Definition:

Carrying out alcoholic fermentation and, possibly, malolactic fermentation of wines in small capacity wooden containers.

Objectives:

a)        To favour natural physical and chemical mechanisms leading to the enriching of wine through substances released by wood when containers have a maximum capacity of 600 litres;

b)       Allow the transformation by micro-organisms of substances released by wood;

c)        To obtain the closest possible contact between lees and wine, in order to favour the migration of wine yeast compounds into wine, through autolysis.

Prescriptions:

a)        It is recommended to use partially clarified must at an appropriate temperature;

b)       It is recommended, for the process to be efficient and to favour the maximum dissipation of fermentation heat, that the volume/wood surface ratio be optimised, in accordance with the product to be made;

c)        The recipient will be made of wood that keeps its natural structure. Cooperage techniques as defined for the construction of new casks could 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 recipient could be regenerated by usual cooperage methods. In this case, the date should be visibly engraved.

Recommendation of OIV:

Admitted

II.2.3.9 Warm post fermentation maceration of red grapes called warm final maceration

Definition:

Procedure involving the prolonging of fermentative maceration using a warm post-fermentation maceration.

Objectives

a)        Complete the release of skin compounds carried out by pre-fermentative and fermentative maceration.

b)       Improve the polyphenolic structure of wine and colour characteristics.

Prescriptions

a)        Advise against using this technique during harvests with deficiencies in health status,

b)       Ensure that alcoholic fermentation is completely finished

c)        Protect oxidative phenomenon, notably during the wine heating phase by carbon dioxide,

d)       Bring the temperature of blends of wine to 40 to 45°C

e)       Determine length of warm maceration according to grape characteristics and sought after wine type

f)         Cool blends of wine prior to devatting and pressing

Recommendation of the OIV

Admitted

II.2.3.10 Maceration of raisined grapes or their pomace in wine

Definition:

Procedure which involves the maceration in wine of raisined grapes or grapes affected by noble rot or their pomace following fermentation.

Objectives:

a)        To increase content of:

• sugar in wine,
• phenolic compounds in wine,
• aromatic compounds in wine.

Prescriptions:

a)        The length of maceration depends on the characteristics of the wine, the grape variety and the style of wine desired.

b)       Avoid excessive extraction of phenolic compounds brought on by a too lengthy maceration.

c)        The wine, raisined grapes and pomace obtained following fermentation must all be from the same vintage.

Recommendation of the OIV

Admitted