(a) General. Acids of the kinds occurring in grapes or other fruit (including berries) may be added within the limitations of § 24.246 to juice or wine in order to correct natural deficiencies; however, no acid may be added to juice or wine which is ameliorated to correct natural deficiencies except that in the production of grape wine, tartaric acid may be used to reduce the pH of the juice or wine. If tartaric acid is used to correct the pH of grape juice or wine, the fixed acid level of the juice shall be measured prior to the addition of any tartaric acid to determine the maximum quantity of ameliorating material allowed. In addition, when using tartaric acid to reduce the pH of ameliorated grape juice or wine, the pH cannot be reduced below 3.0.

(b) Grape wine. Tartaric acid or malic acid, or a combination of tartaric acid and malic acid, may be added prior to or during fermentation, to grapes or juice from grapes. In addition, after fermentation is completed, citric acid, fumaric acid, malic acid, lactic acid or tartaric acid, or a combination of two or more of these acids, may be added to correct natural deficiencies. However, the use of these acids, either prior to, during or after fermentation, may not increase the fixed acid level of the finished wine (calculated as tartaric acid) above 9.0 grams per liter. In cases where the wine contains 8.0 or more grams of total solids per 100 milliliters of wine, acids may be added to the extent that the finished wine does not contain more than 11.0 grams per liter of fixed acid (calculated as tartaric acid).

(c) Fruit wine. Only citric acid may be added to citrus fruit, juice or wine, only malic acid may be added to apples, apple juice or wine, and only citric acid or malic acid may be added to other fruit (including berries) or to juice or wine derived from other fruit (including berries) to correct natural deficiencies to 9.0 grams per liter of finished wine; however, if the wine contains 8.0 or more grams of total solids per 100 milliliters of wine, acids may be added to correct natural deficiencies to the extent that the finished wine does not contain more than 11.0 grams per liter of fixed acid (calculated as malic acid for apples and citric acid for other fruit (including berries).

(d) Other use of acid. A winemaker desiring to use an acid other than the acids allowed in paragraphs (a) and (b) of this section to correct natural deficiencies shall follow the procedure prescribed in § 24.250. A winemaker desiring to use acid to stabilize standard wine shall follow the requirements prescribed by § 24.244.