Chaptalization & Sugar Addition Calculator
Sugar to add to wort, cider or must to reach a target gravity (and ABV).
How it works
Enter your current gravity, the gravity you want to reach, and the batch volume; the calculator returns the grams of sugar to add. Each sugar contributes a different number of gravity points per gram per litre, so switching the sugar type changes the amount. The potential ABV figure is the alcohol the added gravity would produce if it ferments fully.
grams = (targetPoints − currentPoints) × litres / pointsPerGram
points per g/L: sucrose 0.386, dextrose 0.355, DME 0.367, honey 0.292
Sources: gravity-points sugar contributions, as documented by Brewer's Friend.
Assumes the added sugar fully dissolves and ferments out. Honey and malt extract carry their own residual character, so the real ABV and flavour will vary with attenuation.
Frequently asked questions
- What is chaptalization?
- Chaptalization is adding sugar to wort, must, or cider before or during fermentation to raise its gravity, and therefore the finished alcohol. It does not add flavour body the way malt does - the added sugar ferments out almost completely, leaving alcohol behind.
- Which sugar should I use?
- Table sugar (sucrose) and corn sugar (dextrose) ferment cleanly and dry, ideal for boosting alcohol without flavour. Dry malt extract adds maltiness and body. Honey contributes its own character. Each has a different gravity contribution per gram, which this calculator accounts for.
- How much will the gravity bump raise my ABV?
- Roughly, every 0.010 of added gravity adds about 1.3% ABV if it ferments out. The calculator shows the potential ABV from the gravity increase so you can size the addition to a target strength.