Meanwhile, he became a kvass merchant and exercised this trade for several months.
"Contemporary Russian Novelists"
Serge Persky
Go to Sidorov's and get some kvass, you jade!
"The Darling and Other Stories"
Anton Chekhov
We were taken to the refectory and seated at many tables to a peasant dinner: cabbage soup and porridge, bread and kvass, just as they are served in Russia itself.
"A Tramp's Sketches"
Stephen Graham