How to Ferment Fruits

Fruit ferments in a nutshell

Fermenting fruit is similar in principle to fermenting vegetables. Microbes use the natural sugars in the fruit and produce acids, and sometimes a little alcohol and carbon dioxide. Because fruit is much sweeter than cabbage or cucumbers, the results taste different: tart, lightly fizzy, and often a bit boozy if left long.

One important caution up front: the National Center for Home Food Preservation (NCHFP) and USDA publish tested methods for some vegetable ferments such as sauerkraut and brined pickles, but I am not aware of equivalent tested recipes for fermented fruit. Treat the methods below as common home practices, not tested preservation methods. Keep fruit ferments in the refrigerator and eat them within a few weeks.

Three common approaches

Salt (lacto-fermentation): Fruit is mixed with a small amount of salt, or covered in a light salt brine, and held under liquid. Some recipes use about 2 percent salt by weight of the fruit.
Honey: Fruit is packed in a jar and covered with honey. The honey draws juice from the fruit and thins out, and wild microbes produce fizz and tang over days to weeks.
Sugar and water (for drinks): Fruit scraps are fermented in sweetened water, as in tepache. See what to do with fermented pineapple.

Which fruits are easy to ferment?

Firm, ripe, unblemished fruit tends to work best. Commonly used examples include:

Berries, such as blueberries and strawberries
Cherries (see how to ferment cherries)
Stone fruit such as peaches and plums
Grapes
Apples and pears, chopped
Citrus, often sliced thin for salt-fermented lemons
Pineapple, usually for drinks

Soft or overripe fruit can turn mushy and ferment unpredictably. Discard anything moldy or damaged before you start.

Basic salt-ferment method

This is a general approach based on common home recipes.

Wash the fruit, remove stems, pits and seeds, and cut large pieces into halves or quarters.
Weigh the prepared fruit. Weigh out salt equal to about 2 percent of that weight, using non-iodized salt. For 500 grams of fruit, that is about 10 grams of salt.
Toss the fruit and salt together and let it rest 10 to 15 minutes so juice starts to release.
Pack into a clean jar with the juice. Add a little non-chlorinated water if needed so the fruit is covered.
Press the fruit under the liquid with a fermentation weight or a water-filled bag, leaving an inch or two of headspace because fruit ferments can bubble up.
Cover loosely, or use an airlock lid, and keep at cool-to-moderate room temperature, roughly 60 to 75 degrees F.
Taste daily after the first day or two.

Honey-fermented fruit

Place fruit in a jar and cover with honey, leaving generous headspace, since the mixture can foam. Weigh the fruit down if it floats, loosen the lid or burp daily, and set the jar on a plate in case it overflows. Fermenters report anything from a couple of days (cut, soft fruit) to a week or two (whole blueberries). Do not give honey-based preparations to children under one year of age.

How long does it take?

Fruit usually ferments faster than vegetables because of the sugar. Many recipes call for roughly 1 to 4 days for berries and soft fruit, and a week or more for denser fruit or heavier honey. Taste early and often. Once the fruit tastes pleasantly tart, refrigerate it. Longer ferments tend to taste sharper and more alcoholic.

What it should taste and smell like

Aim for “slightly tart” and fruity with a clean aroma. A little fizz is normal. A strong alcohol smell, vinegar smell, or sharp solvent-like odor suggests the fruit has fermented further than intended. It might still be usable as a cooking ingredient if it otherwise looks and smells fine, but if in doubt, throw it out.

Safety, mold, and botulism

Keep fruit submerged. Fruit that floats above the liquid is where mold usually appears.
Mold: Fuzzy, colored, or raised growth means discard the whole jar. Do not scrape it off and eat the rest.
Botulism: Fruit is generally more acidic than vegetables, which helps, but I do not have tested data for homemade fruit ferments. The safest approach is to keep them refrigerated, make small batches, and discard anything that looks, smells, or tastes wrong. Do not store fruit ferments at room temperature for long periods, and do not try to can them without a tested recipe.
Pressure: Fermenting fruit produces gas. Use loose lids, airlock lids, or burp jars daily. Never seal a fermenting jar tightly and leave it.
People who are pregnant, immunocompromised, or avoiding alcohol should check with a health professional before eating fermented foods, as fruit ferments may contain small amounts of alcohol.

How long do fermented fruits keep?

Home fermenters commonly report a few weeks to about two months in the refrigerator, and fruit ferments generally do not keep as long as vegetable ferments. Because there is no tested guidance, I would lean toward the shorter end and use your senses to judge.

Is fermenting fruit good for you?

Fermented foods are often discussed for their potential digestive benefits, but the evidence varies by food, and fruit ferments have not been studied as extensively as foods like yogurt or sauerkraut. Fermentation also uses up some of the sugar in the fruit, though the finished product can still be sweet. Salt adds sodium, so keep portions modest if you watch your sodium intake. Think of fermented fruit mainly as a flavor food.

Ways to use fermented fruit

Spoon over yogurt, oatmeal, or ice cream.
Add to salads, particularly with bitter greens or strong cheeses.
Serve with roasted meats, similar to a chutney.
Blend into dressings or sauces.
Use the liquid in drinks or shrubs, if it tastes good.

If you want a shelf-stable fruit preserve instead, use a tested recipe such as those in our beginner’s guide to making jam or canning pears with cinnamon. For more flavor ideas across the whole category, see our guide to fermented foods that taste good.