Save Your Fruit Scraps to Make Bubbly Fruit Kvass

Fruit scraps in a jar sitting on a marble top. The background is distressed grey metal.
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Brew this fruit kvass out of mere scrappy bits and enjoy a carbonated drink during Plastic Free July—or any time!—without the fossil-fuel-based plastic soda bottle. (Cans are lined with plastic and also contribute to plastic pollution.)

Save strawberry cores, plum peels, intact peach and cherry pits that have stubborn bits of flesh stuck to them—all the fruit scraps that you’d ordinarily compost. If you don’t have enough fruit scraps to brew a bottle of fruit kvass, stash your scraps in the freezer until you’ve accumulated enough. The bacteria and yeast that ferment your drink won’t die in the freezer—they simply take a little nap.

Combine these scraps in a clean jar with water and a bit of sugar, stir daily and once the brew starts to bubble, taste it. If you like the flavor, strain and bottle it. If you’d like it less sweet, let it ferment longer.

The sugar feeds the bacteria and yeast

Choose from granulated sugar, sucanat, coconut sugar, rapadura or honey (preferably raw for extra microbial goodness). You want caloric sugar that will feed the microbes. As the bacteria and yeast feast, they excrete acids and gases that ferment the drink and carbonate it. Depending on your kitchen environment, the drink will likely start to bubble around the second or third day.

This fruit kvass provides just a hint of sweetness. The longer you allow it to ferment, the more sugar the microbes will consume and the less sweet the drink will taste. If you’d like it sweeter, slow the fermentation early by moving the strained drink to the refrigerator while it still tastes sweet. Or slightly increase the amount of sugar. Or do both.

Crank up the carbonation

You want to drink or bottle the fruit kvass while it’s bubbly. If you wait too long, it will become flat and turn into mild vinegar (which is useful stuff so don’t throw it away!). At this point, you can strain the liquid and enjoy the fruit kvass as is. But if you’d like more carbonation, funnel it into a flip-top bottle if you have one and let it sit at room temperature. As the drink continues to ferment, the tight seal traps the carbon dioxide building up in the bottle, increasing the fizz. A screw-top bottle will render a good amount of carbonation also if you don’t have a flip-top bottle.

After the bottle has sat on the counter for a day, burp it (i.e., open the lid slightly). If it has carbonated so much that you can’t get it open for fear of spraying the drink all over your ceiling, chill it in the refrigerator to calm it down. If the bottle emits no hiss at all, let it sit for another day or two before moving it to the refrigerator. But don’t let it go longer than a couple of days without burping. The gasses can build to dangerous levels and lead to exploding bottles. (I’ve never had this happen and hope I never do.) Storing your bottle in a box, cupboard or closet will help contain potential messes.

Fruit scraps in a jar sitting on a marble top. The background is distressed grey metal. This is the first day of fermenting the fruit kvass.
Day 0 of a jar of fruit kvass
A glass jar filled with fruit scraps and water is full of bubbles during active fermentation of fruit kvass
Day 2. Notice the fading colors, a sign of successful fermentation.

Make a second batch of fruit kvass

After straining and bottling the fruit kvass, make a second batch. Because the fruit will contain less flavor and sugar, add less water to this second infusion to prevent a diluted flavor. The good bacteria and yeast that have proliferated all over the fruit will kickstart the ferment and the second batch will be ready quickly, possibly in less than a day.

A jar of fermenting fruit scraps and a bottle of fruit kvass, ready to drink. The background is distressed grey metal. The jar and bottle are sitting on dark brown wood.
A second batch of fruit kvass in a jar on (Day 0) and fermented fruit kvass (just bottled)
A jar of fruit scraps fermenting in a jar. The jar is sitting on white and grey marble with a distressed metal background.
After less than 24 hours, the second batch is ready to bottle
A half-full bottle and half-full glass of fruit kvass. The background is distressed grey metal. The glass and bottle are sitting on grey and white marble.
Foamy fruit kvass after two days of fermentation in the bottle (the secondary fermentation) and a few hours of chilling in the refrigerator
Fruit scraps in a jar sitting on a marble top. The background is distressed grey metal.
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4.75 from 4 votes

Scrappy Fruit Kvass

Make a bubbly and refreshing drink using fruit scraps and peels


  • 1 cup fruit scraps
  • 2 tablespoons sugar or raw honey or more if you want a sweeter drink
  • 2 cups water


  • Stir 2 tablespoons of sugar into 2 cups of water in a clean 4-cup jar. Add the cup of fruit scraps. Close the jar or cover it with a piece of cloth secured tightly around the mouth of the jar. Stir a few times daily.
  • Depending on your kitchen environment, from between 2 to 5 days, the fruit kvass should be very bubbly and perhaps a bit frothy, while the colors of the fruit will have faded. Strain it and set aside the fruit scraps. Drink immediately or bottle it to increase the carbonation. After the bottles have sat in a cupboard or cardboard box for a day, burp them by slightly opening the lids. If you can't get them open for fear of spraying the drink all over your ceiling, chill them in the refrigerator to calm the drink down. If they emit no gas, let them sit another day or two to carbonate further. Burp them again to prevent explosions. Chill the bottles in the refrigerator before serving.
  • Make a second infusion with the fruit scraps. Concentrate the remaining fruit flavors by using less water for the second batch, about 1 cup. (Add more water if the 1 cup doesn't cover the fruit scraps.) Stir in 1 tablespoon of sugar and add the scraps. The second infusion will ferment quickly, often in less than a day. Strain the fruit kvass and either drink it immediately or bottle it. Compost the pale, spent scraps.

Find more fermented drinks in my cookbook. Learn more about the book here!

US Cover of my book

13 Replies to “Save Your Fruit Scraps to Make Bubbly Fruit Kvass”

  1. I was looking for your post in my email after getting home from work, but figured I got it wrong regarding the day, so I posted on the previous tea posting about CBC’s radio running commentary today regarding “plastic-free”. I was driving much of the time, but if this many listeners on the show and email commentaries are only now staring to think regarding changing everyday habits and don’t realize we are really in climate change, then I fear for my kids and the world they are going to inhabit. The 2 journalists/broadcasters “found someone in their office who uses and freezes with silicone bags. It was a day dedicated to the ban that went into effect by Cdn. government that producers of single use plastic must stop production by x date.

    There were many concerns on behalf of the disabled who can only drink liquids, which I understand as I have worked with these populations in my career. The broadcaster (not Gloria today) let them have their air time which I think was great, as I still get also stunned by the number of people in everyday life, educated among them that know nothing about how people who cannot use a spoon or fork and don’t want to depend on someone to feed them in their adult life actually consume most of their food, want a bendable plastic straw to take to cafe’s or restaurants. I think it should be the responsibility of cafe and restaurants to build up a cache of them while they are still available, I am sure family members of disabled children and adults will save up stores, but there is a lot of life to be lived for such people. I empathize with the women who described the soggy use of a paper straw, I have witnessed that in my work. However, i agree that production has got to stop in Canada, but how many Canadian goods are actually produced in Canada? A moot point.

  2. Hello – just a small question for clarification: for this and other beverages, when it’s time to chill them, do you burp the bottle and then immediately put it in the fridge? Or do you burp it and wait for it to bubble up again before putting it in the fridge? I am having hit-or-miss results keeping the bubbly-ness in my chilled drinks. (No fizz when I open and pour, but they still taste/feel carbonated, if that makes sense.)

    1. Hello! This tends to be very carbonated. I would burp it and if it’s very fizzy, put it in the refrigerator right away. If you don’t get much of a pop, leave it out at room temperature for another day or even two. I wouldn’t let it sit longer than two days though, unless it’s completely flat for some reason. I hope that helps!

      1. That does help; thank you! 🙂

  3. Would cherry pits with little bits left from a pitter work for this? Thank you in advance for your time 😊

  4. Hi, I have left the fruit scraps mixture out on the counter following the recipe, but the layer on top looked moldy after the first day. I took the some of the top layer off and put it in the compost, the second day looks moldy again. Does it look like that for you?

  5. This recipe has been a wonderful addition to our repertoire. We are dairy-free so can’t do kefir, my youngest doesn’t seem to like any kombucha (too fizzy), and I cannot seem keep water kefir grains alive. Enter fruit scrap kvass! (or “k’boss,” as my littlest calls it). Two mango pits will make a whole jar of kvass. A pineapple core and a handful of strawberry tops do as well. I keep an open jar in the freezer and toss fruit bits in until I have enough. None of us in the house ever get any of the kvass because my littlest downs it all as soon as there’s a bottle in the fridge. So glad to have an easy, waste-reducing, probiotic beverage that my littlest loves!

    1. That’s amazing you can make it with a mere two mango pits. Thanks for sharing! I’m so glad your family likes the k’boss!

  6. Hi Anne Marie,
    Would this work with citrus fruits? I have so many juiced lemons and limes but unsure if that would alter the desired effect.

  7. I was just wondering if any kind of fruit is ok…like apple peels. Most of what I see mentioned are berries or stone fruits. Just curious….

  8. This might be a silly question but is there any reason this recipe can’t be multiplied? I don’t think there is but would hate to have an explosive issue because there was something I hadn’t considered.!

    1. Hello! Not silly at all. I made a big batch a few weeks ago. Just scale everything up and use a bigger jar or divide it among smaller jars if you don’t have one that’s big enough. You can also just drink it as soon as it’s ready but if you do make a big batch, that will be more than you can drink and you’ll likely want to bottle what’s left. Bottling is what can lead to explosions. Be sure to burp the bottles daily. And if it’s super carbonated, you can also open it outside so it doesn’t spray your ceiling.

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