About FermentCalc

FermentCalc is a collection of free, no-signup calculators for home fermentation - brine percentages, kombucha, sourdough, beer and more. Everything runs in your browser: nothing you type is sent to a server or used to build a profile.

How the numbers are sourced

Every reference value behind a calculator - a salt concentration range, a salt density, a conversion factor - cites its source on the page where it is used, typically published recipes, university extension guidance, manufacturer nutrition labels or USDA FoodData Central. Where sources disagree or the value is an approximation, we say so. The formulas themselves are shown on every tool page, so you never have to trust a black box.

Contact

Found a bug, a wrong number, or a mistranslation? Write to [email protected]. Corrections are reviewed by hand.