Where does “квас” come from?

квас (Bulgarian) comes from Russian ква́с, from Old East Slavic квасъ, from Proto-Slavic kvasъ, from Proto-Indo-European kwh₂et- — to ferment, become sour; to boil, foam.

квас (Bulgarian): leaven, yeast, barm a catalyst that causes fermentation

Definitions

  1. leaven, yeast, barm a catalyst that causes fermentation

Ancestry of “квас”, step by step

StepLanguageWordMeaning
1Russianква́сkvass
2Old East Slavicквасъ—
3Proto-Slavickvasъleaven, fermented drink
4Proto-Indo-Europeankwh₂et-to ferment, become sour; to boil, foam
Every word from Proto-Indo-European kwh₂et- →Every word from Proto-Slavic kvasъ →Every word from Old East Slavic квасъ →