4. Acidification must be achieved solely by the use of not more than 2 g per litre of tartaric, citric, malic or lactic acid, expressed as g/L of sulphuric acid.
Deacidification must be achieved solely by the use of not more than 2 g per litre of calcium carbonate, neutral potassium tartrate and double calcium salt of tartaric and malic acids, expressed as g/L of sulphuric acid.
Acidification and deacidification are mutually exclusive.
Nothing in this section may be construed to prohibit malolactic fermentation.