© 2024
Local NPR for the Cape, Coast & Islands 90.1 91.1 94.3
Play Live Radio
Next Up:
0:00 0:00
Available On Air Stations

A fizzy fermented drink made from leftover bread

Home fermentation of kvass in glass jars.
Andrij Bulba
C.C. 2.0
Home fermentation of kvass in glass jars.

In May of 1970 my neighbor Helen Miranda Wilson went to the Soviet Union. She spoke some Russian — her mother moved from northeastern Europe to Wellfleet before Helen was born here — and on a cool spring day in Leningrad, Helen stumbled on a street vendor with a huge metal vat on the back of his truck.

"And a man was dispensing something out of it, on the street. And people were like, you know, lined up, getting a glass and chugging it down. I thought, What is this? So I asked, because I could speak enough Russian, you know, [Russian phrase]. And the guy said, Well, you know, it's kvass," Helen explained.

Helen wasn’t sure what kvass was. But she wanted to try it.

"And so I had a glass of it, and it was sublime. It just had this ever so slightly—I don’t want to say sour, but it had a little bit of an acidic edge, and it was slightly fizzy and of course it was room temperature, even though it was May, it was cool out."

Helen loved it. The flavor, the fizz, everything about this drink made from fermenting stale bread with water and sugar. But when she got home, she forgot about it for almost forty years.

"So years later, here I am in Wellfleet, I’m like in my early 60s, and I’m fermenting my ass off. Everything I can get," she said.

Helen was making kombucha and kefir and sauerkraut and her own sourdough bread. She had a whole microbiome living in her kitchen. And one day she glanced over at a loaf of leftover sourdough rye and raisin bread that was slowly getting hard and stale, and remembered.

"I thought why don’t I try making kvass! So here's how I did it. I cut it up. And I soaked it in a stainless-steel pot that was well cleaned out. With water that I had brought to a boil and simmered a little bit."

Helen did this to kill off any bacteria in the water. She didn’t want the yeasty lactic acid bacteria in the bread having to compete with any other micro-organisms—and then she poured this sterile water over the bread and stirred in two big spoonfuls of sugar.

"So I did that and I left these hunks of bread on the stove in a warm kitchen for 24 hours and I'd give it a stir and I'd sniff it and it got it started to get very faintly foamy. It got that good kind of smell, it’s a clean, sharp smell, you know like my sourdough starter has that too."

When the foam and this almost yogurt-like smell started to develop, Helen strained out the bread and added a little more sugar, to kickstart a second round of fermentation.

Home-made mint kvas.
CC 2.0
Home-made mint kvas.

"And I let that set at room temperature for, you know, half a day or something, depending how cool the kitchen was. And remember, there was some raisins in there often, and raisins, as we know, from wine really have a lot of wonderful molds and things to increase fermentation," she explained.

"So, you know, the raisins that were incidentally in the bread, you know, worked. But I didn't do anything fancy. I didn't, as they tell you in some recipes send away for kvass, bottled kvass, which you can use as a starter, I didn't use any of my sour dough as starter. It just wasn't like that. It was like, okay, bread, do your thing. And if it doesn't work, screw it. And guess what? I got wonderful kvass."

Helen was hooked. She says kvass is not only an excellent use of old sourdough, but also a perfect non-alcoholic alternative to beer.

"It’s not hoppy like beer, like nonalcoholic beer. But it has that nice, fermented taste that goes really well with food. I have to say for those of us who want to drink something that isn't a soft drink, particularly not a soft drink with a sugar substitute, and you want that carb and that fizz and that liquid part for a nice meal. It's perfect."


Basic Kvass Method, Helen Miranda Wilson Style

A note about the bread: Helen's favorite is rye with raisins, but you could always throw in a handful of raisins to a regular sourdough loaf. The key is to use bread without preservatives, which will interfere with the bacterial processes.


2 quarts water (unchlorinated)
1/3 to 1/2 loaf stale sourdough
about 1/4 cup granulated sugar
optional: a handful of raisins


Fill a smallish stainless steel soup pot with about 2 quarts of water. (When you're choosing a pot, think about the bread size, and cut it up if needed. Ideally you want the pot to just fit the bread, so that the water will fully cover the loaf.) Bring the water to a boil and simmer for a few minutes, to kill any bacteria.

Add the bread (Helen does not cut it up or toast it, just puts in the whole hunk; some recipes recommend toasting the bread both to add flavor and to kill off any molds, if it's getting to that stage). Add two tablespoons sugar, the optional handful of raisins if desired, and stir well. Then let the bread sit in the water in the pot—covered with either a lid or a dishtowel to keep away bugs—for 24 hours. Give it a stir and look and it and sniff it.

When the liquid starts to get very faintly foamy and develops a clean, yeasty smell, strain out the bread through cheesecloth or a very fine grain sieve. Discard the bread.

Now pour the liquid into a large jar and add about 2 teaspoons of sugar (the general rule is to add an additional 1/2 tsp per pint of liquid). Screw on the lid. This will kick off a second round of fermentation. Let this jar sit for another 12-18 hours out at room temperature, and then put it in the fridge.

That's it! You should have a golden/golden-brown, slightly fizzy, delightful beverage. Helen recommends it cold.

For other links from around the web, I found these helpful!

Regular kvass tutorial:


A variation is beet kvass!


A little kvass history:


An avid locavore, Elspeth lives in Wellfleet and writes a blog about food. Elspeth is constantly exploring the Cape, Islands, and South Coast and all our farmer's markets to find out what's good, what's growing and what to do with it. Her Local Food Report airs Thursdays at 8:30 on Morning Edition and 5:45pm on All Things Considered, as well as Saturday mornings at 9:30.