Once testing is complete, you will know what your acid levels are. Compare this value with the suggested Acid level. Ranges in the chart shown above.

If you need to increase acidity:

  • Add acid blend to increase acidity.
  • 3.9 grams of acid blend will raise the acidity of ONE gallon of must by 0.1 %.

As a helpful hint for those who do not have scales, 1/4 teaspoon of acid blend weighs approximately 1.2 grams; a teaspoon weighs about 5.1 grams.

If you need to decrease acidity:

  • Add calcium carbonate to lower acidity, but only to reduce acidity by 0.4 % or less.
  • 2.5 grams of calcium carbonate will lower the Acid level in ONE gallon of must by approximately 0.1 %.

One-fourth of a teaspoon of calcium carbonate weighs about 0.5 grams; one teaspoon of calcium carbonate weighs about 2.6 grams.

General tips:

  • Until you get the hang of it, test your must twice to be sure of an accurate reading.
  • If you need to make an adjustment to the must based on your testing, go slow and lean when adding acid blend or calcium carbonate (as the case dictates). You can ALWAYS add more chemicals to make further adjustments, but if you overshoot your mark it's difficult to take it out!
  • Take a follow up sample to see how your adjustment went.
  • Keep good records so you can duplicate or adjust future batches of wine.

Recommended Acidity Levels

Since each style of wine is made to taste different, it makes sense that each wine style would have its own range of recommended acid levels.

The chart below provides guidelines for acidity based on the type of wine you are making. Individual tastes vary, of course, so the information shown are recommendations only:

Wine Style Recommended Acidity Range
White Wines 0.60 - 0.75%
Red Wines 0.60 - 0.70%
Dessert Wines 0.50 - 0.60%
Fruit Wines 0.50 - 0.60%

The numbers in the chart represent total acidity as a percentage by volume; winemakers refer to this as the titratable acidity, or T.A. for short.