get FermentCalc

Cider Acid Adjustment Calculator

Enter your juice volume, the acidity you measured and the acidity you want, and get the malic acid to weigh out - plus an optional tannin dose for mouthfeel.

L

The cider or juice you are adjusting, before or after fermentation.

%

From a titration kit, expressed as malic acid percentage. Store juice often sits near 0.3-0.5%; dessert apples run lower than cider apples.

%

0.6-0.7% reads bright and refreshing in still cider; much above 0.9% turns sharp. Taste as you go - acid shows differently once carbonated.

Results

Malic acid to add
28.5g
Tannin to add
0 g
Resulting acidity
0.65% TA as malic acid

For small adjustments, blending in a tarter juice is gentler than adding dry acid - it lifts acidity while diluting everything else slightly, instead of sharpening one dimension.

How the acid math works

TA percent as malic acid means grams of acid per 100 ml, so a 0.1% gap equals 1 g per liter: malic grams = (target - current) x 10 x liters. Tannin, when selected, is a flat 0.2 g per liter - the usual dose to give low-tannin dessert juice some structure. Dissolve the acid in a little of the cider first, stir well, then re-titrate before trusting the result.

malic (g) = (target TA - current TA) x 10 x L; tannin (g) = L x 0.2

Balanced acid makes the sweetness readings honest too: check where the batch stands with the cider ABV calculator, and for fruit-heavy ciders the melomel fruit addition calculator shows what the fruit itself contributes.

Frequently asked questions

Malic or citric acid for cider?

Malic. It is the acid apples already carry, so it reads native; citric acid tastes sharply lemony in cider and marks the drink as adjusted. Winemaking blends usually list malic separately for exactly this reason.

How do I measure TA at home?

An inexpensive titration kit: draw a measured sample, add phenolphthalein indicator, and count the milliliters of 0.1 N sodium hydroxide it takes to turn the sample pink. The conversion to percent malic acid comes with the kit - the number this calculator needs.

Can I lower acidity instead of raising it?

Not by adding anything - acid only goes up. To soften a tart cider, blend in a lower-acid juice, or use a malolactic culture or commercial deacidifier before bottling. Those are fermentations and chemistry of their own, so plan them well before packaging.