Kvass is a fermented drink made from bread, according to the Harbin company account that documents the local technique. The idea links two products often encountered separately: a substantial baked loaf and a light drink. In one documented method, large bread is broken up and soaked to draw out its flavor; the resulting liquid becomes the base for fermentation. Here bread supplies the grain base from which the drink begins.
From the journal
Kvass: when bread becomes a fermented drink
Harbin’s bakery tradition supplied a base for kvass, a drink made by extracting flavor from bread and fermenting it with yeast and lactic cultures.
In the same city · Harbin ↗
Bread takes a second form
Extraction, then fermentation
A company description says its large-loaf kvass uses direct extraction from bread, followed by fermentation with yeast and lactic-acid bacteria. A more detailed process account describes soaking toasted bread pieces, filtering the liquid, fermenting it, then filtering and packaging the beverage. In the documented method, bread contributes toasted grain flavor to the liquid; fermentation then gives the drink its characteristic acidity and light effervescence.
Bakery and beverage together
Harbin’s kvass story sits beside the city’s large-loaf bread tradition, but the two remain distinct products. A loaf is baked and eaten; kvass uses bread as the starting ingredient for a brewed drink. That link offers a useful way to read local food culture: one familiar product can become raw material for another. The documented method links Harbin’s bread-making culture with a fermented drink, without reducing all kvass to one recipe.