Acid Titration in Juice/Must
Before making any adjustments, determine the acid content (see instructions below).
The acid content of the juice affects the taste and the aging characteristics of the wine.
Wine juice with an acid content under 0.6 may taste flat and has a higher susceptibility to
wine diseases. Where as wine juice with a high acid content, above 0.9, may taste
sharp and will require extensive aging times to be palatable.
The acidity of wine juice can be increased by adding natural organic acids such as
Tartaric Acid, Citric Acid, Malic Acid, and Tannic Acid. The preferred method is to use a
blend of these acids. To lower the acidity of a wine juice, add water, a low-acid juice or
calcium carbonate. Usually, a combination of these methods is required to achieve the
proper acid level. Here at Heartland Vineyards, we use the following method to
determine the total acidity of the juice/must:
EQUIPMENT NEEDED:
1 Acid Titration Kit
(Containing 1 20cc syringe, 1 eye dropper, ½ oz. Indicator solution
[phenothalein], 1 / 5 Normal NaOH [Sodium Hydroxide])
1 Small Glass
1 Small Spoon
Well lighted area
PROCEDURE FOR ALL TITRATIONS (RED AND WHITE)
1. Using syringe, place 15cc of juice in glass. Add 3 drops of indicator solution to
the juice. Mix well with spoon or by swirling.
2. Rinse syringe out with water only and dry with towel. Re-Fill syringe with exactly
10cc of NaOH, ensure all air bubbles are removed.
3. Slowly add the NaOH to juice while stirring. Look for color changes that last
longer than 30 seconds. White juices will turn pink and hold it. Red juices will
change color to grayish-green, blue, black or another color different than the
original color.
4. Determine how much NaOH was used by subtracting the finish amount from the
starting amount (20cc). Multiply this number by .10 to determine the total acidity
of your juice. The ideal acidity is 0.777. Adjust you juice accordingly. The
industry range is 0.600 to 0.900 for wine juice. Finished wine will have a different
acid level.
If you have any questions, please call us. Remember, KEEP THESE AND ALL
CHEMICALS OUT OF THE REACH OF CHILDREN!
J. W. Dover, Inc.
Beer & Wine Making Supplies
24945 Detroit Road Westlake, Ohio 44145 (440) 871-0700