From Fruit to Fermentation

Whether you’re crafting a strawberry wine or experimenting with peaches, one of the first questions hobby winemakers ask is how strong the finished product will be. Alcohol by volume (ABV) indicates the percentage of alcohol relative to the total liquid. This calculator uses the widely accepted formula derived from measuring your wine’s gravity before and after fermentation.

ABV Formula

The density difference reveals how much sugar turned into alcohol. We calculate it using:

where $\mathrm{OG}$ is original gravity and $\mathrm{FG}$ is final gravity. This approximation assumes most sugar converts to ethanol. It provides a reliable estimate for homemade wines fermented with common yeast strains.

Using the Calculator

Take a hydrometer reading of your must before adding yeast and another once fermentation is complete. Input those values to instantly see the ABV. If you’re measuring in Brix, convert to specific gravity first or consult a conversion chart. For added accuracy, make sure readings are taken at the same temperature or correct for temperature differences.

Beyond Numbers

Knowing ABV is useful when planning how sweet or dry you’d like the final product. It also helps ensure bottles aren’t over-carbonated if you’re sparkling the wine. Keep detailed notes on your starting ingredients and yeast choice so you can reproduce that perfect batch again.