RESOLUTION OIV-OENO 597-2018

MODIFICATION OF THE METHOD FOR THE DETERMINATION OF TOTAL ACIDITY IN VINEGAR

THE GENERAL ASSEMBLY,

In accordance with Article 2, paragraph 2 iv of the Agreement of 3 April 2001 establishing the International Organisation of Vine and Wine,

At the proposal of the “Methods of Analysis” Sub-Commission,

CONSIDERING that point 6, the “Technique” of the method, outlines the following: 'In a 250 ml conical flask, add 10 ml of vinegar. Add recently boiled and cooled water so that the solution is barely colored. Add a few drops of the indicator and titrate with the sodium hydroxide solution until a persistent pink color is obtained',

CONSIDERING that the principle of this method (in point 2) is the 'neutralization of acids in sample by alkali solution',

CONSIDERING that the use of cold, boiled water is intended to ensure that the water used is free from – which produces an acidic reaction and could influence the final result of the titration,

CONSIDERING that water free from may be obtained using other techniques,

CONSIDERING that, from a technical viewpoint, the important thing is to use water that does not induce an acidic reaction (i.e. is free from ) and not the technique used to obtain this water,

CONSIDERING the trials presented during the SCMA meeting (the strikethrough text will be deleted),

DECIDES to modify point 6 in Resolution OIV-OENO 52/2000 as follows:

6.      TECHNIQUE 1

In a 250-mL conical flask, add 10 mL of vinegar. Add water, free of carbon dioxide, so that the solution is barely coloured. Add a few drops of the indicator (3.2) and titrate with the sodium hydroxide solution (3.1) until a persistent pink colour is obtained.

Note: Titration may also be monitored by potentiometry, taking into consideration the respective equivalence point.