Where does “クワス” come from?
クワス (Japanese) 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.
クワス (Japanese): kvass
Ancestry of “クワス”, step by step
| Step | Language | Word | Meaning |
|---|
| 1 | Russian | ква́с | kvass |
| 2 | Old East Slavic | квасъ | — |
| 3 | Proto-Slavic | kvasъ | leaven, fermented drink |
| 4 | Proto-Indo-European | kwh₂et- | to ferment, become sour; to boil, foam |