How to Make Bread Kvass

Making bread kvass is a great way to use up stale sourdough bread. It's light and refreshing, nice and fizzy. And it's fermented, so it contains probiotics.

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As much as I love my homemade sourdough bread, there is always some stale bread left over because it makes a giant loaf of bread. And since I hate wasting food, I'm always looking for something to do with it.

I've made croutons several times, and sometimes I freeze any leftovers and save them for stuffing. But when I don't need either of those, I can make a delicious and refreshing beverage.

Wait, a drink made out of bread?? That's right, you can turn your old, stale sourdough bread into deliciously fizzy and refreshing Bread Kvass.

What is bread kvass?

In the ever-growing popularity of fermented beverages, kvass hasn't really caught on yet (perhaps it's the name - insert "Kiss my kvass" joke here). But I assure you, it will.

Bread kvass originates in Eastern Europe, popular in countries like Russia and Ukraine. It is commonly sold by street vendors there and is used as an alternative to pop.

I first learned about bread kvass while I was reading a book all about fermented foods. Since I often have bags full of stale bread laying around, I decided to give it a try. After all, if I didn't like it, all I'd be out was bread I wasn't going to eat anyway and a bit of sugar.

How do you make Bread Kvass?

The first step to making kvass is toasting your bread. This can take a while depending on the moisture content of your bread. You're going for a dark toast here, but not completely black.

The degree to which you toast your bread will drastically affect the resulting flavor of your kvass.

The first time I made it, I got distracted and the bread ended up a little black. The resulting kvass was pretty potent - kind of like a dark beer. I have since learned to keep a closer eye on my bread and take it out before the black stage to get slightly mellower kvass.

After the toasting is done, the process is pretty hands-off.

First you steep the bread in water.

Then you strain it (use cheesecloth if you don't want mashed bread in your kvass, and trust me, you don't).

Then comes the first ferment with some sourdough starter.

Another strain and pour into very clean plastic or glass bottles.

Since the kvass will become carbonated, you want to be careful about what type of bottles you choose. You can re-use old 2-liter pop bottles, provided you are able to clean them well.

You can also use sturdy glass bottles. I use glass bottles with swing-tops, and I vent any excess pressure every couple of days just to be on the safe side.

The mixture continues to ferment in the fridge. The yeast from the sourdough starter slowly consumes the sugar and turns it into acid and alcohol.

Does bread kvass contain alcohol?

Yes, kvass does have alcohol in it, but only a very low amount, 0.5-2%. The alcohol content is certainly low enough that you can't taste it, nor feel any effects, and I feel comfortable giving it to my kids in small amounts.

You can start drinking your kvass after 2-3 days, but the longer you leave it, the fizzier and sourer it gets.

Make sure you check the bottles every so often to make sure the pressure isn't getting too high.

Pouring bread kvass into a glass with ice.

Want more recipes that use Sourdough Starter?

Sliced sourdough bread on a wood cutting board — No Knead Sourdough Bread

Sourdough Blueberry Pancakes — Overnight Blueberry Sourdough Pancakes

Kvass Nutrition Notes

I can't even begin to estimate the nutritional information of this bread kvass. I would have no idea how many nutrients are extracted out of the bread, and I also can't predict how much of the sugar will be used for fermentation.

However, I can tell you that the longer the kvass is allowed to ferment, the more sugar will be used up and turned into acid and/or alcohol.

How to Make Bread Kvass

Carissa Serink

Making bread kvass is a great way to use up leftover sourdough bread. It has a light, fizzy taste that's super refreshing. And since it's naturally fermented, it's a great source of probiotics!

5 from 1 vote

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Prep Time 10

Cook Time 30

Total Time 40

Course Beverage

Cuisine European

Servings L

Ingredients

▢ 1 lb sourdough bread sliced (stale is fine)
▢ 3 L water
▢ 1 cup sugar
▢ ¼ cup honey
▢ 1 tablespoon sourdough starter
▢ sprig of mint (optional for flavor)
▢ 2 2 L plastic pop or juice bottles thoroughly cleaned

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Instructions

Heat oven to 350°F. Place bread slices on a wire rack set on top of a baking sheet. Bake until completely dry and dark brown (but not black), flipping slices occasionally. Baking time will depend on the moisture content of your bread.
Boil water using a kettle or pot. Place bread in a large heat proof bowl. Pour boiling water over bread, just to cover. After half and hour, add more water as needed to cover bread as the bread will absorb some of the water. Let bread steep in water overnight.
Line a wire mesh strainer with 2 layers of cheesecloth. Pour bread mixture through strainer into a pitcher. Add additional warm (not hot) water to come to 3L. Stir in sugar, honey and sourdough starter, add the mint. Let sit, lightly covered, in a warm spot until a slight foam forms on the top, 8-12 hours.
Strain mixture through 2 layers of cheesecloth again and pour into plastic or glass swing-top bottles, being careful not to fill each bottle more than ⅔ full. Place bottles into fridge and ferment for 2-3 days. Check bottles occasionally for pressure. If they feel very firm, loosen lid slightly to relieve pressure then reclose.
Kvass is ready to drink after 2-3 days, but it will continue to ferment after that. The longer it is allowed to ferment, the more carbonated and alcoholic it will become, but will still only be lightly alcoholic (maybe 0.5-2%). You can keep it in the fridge for up to a month.