Choose your fruit. Most fruits can be fermented, although some are better than others. Many people prefer to ferment canned or frozen fruit, as this reduces preparation time. If you are using fresh fruit, choose organic and ripe, unblemished produce.
- Fruits such as peaches, plums, and apricots are popular choices for fermentation because they are tasty and retain their color well. Wash the fruit, peel off the skin, and remove any pits.
- Exotic fruits such as mangoes and pineapples ferment well and can be used to make chutney. Remove the peel and cut into uniformly sized cubes before using.
- Grapes can be fermented, but they must be picked with a needle or halved to allow the liquid from the culture to enter the fruit.
Peeled and sliced pears can be fermented, as can apples (although they tend to darken during the process, which some people find unattractive).
- Most berries can be fermented, except blackberries, which do not contain many seeds. Strawberries ferment well in terms of flavor, but the syrup tends to take away their color.
- Use a starter culture. This culture is simply a substance that contains beneficial bacteria. The culture is used to start the fermentation process.
- For most recipes, it is not necessary to use a specific starter culture – they are basically interchangeable.
- Most common starter cultures (mainly for fruit fermentation, rather than vegetable fermentation) are yeast, whey, or starter culture powders.
- However, you can also use an opened probiotic capsule, the liquid from a previously opened jar of fermented fruit, or a fermented beverage such as pure kombucha tea.
- To make a specific type of fermented fruit called Rumtoph (which is used in German and Danish desserts), alcohol such as rum, wine or brande are used to stimulate fermentation.
Add some flavor. In addition to the fruit flavor, you can add other flavors to the container to give more depth to the final product.
- Some popular additions include: cinnamon sticks, fresh mint leaves, cloves, vanilla beans, allspice, orange peel, and almond extract. What you choose is simply a matter of personal preference.
- You can add liquid flavors or extracts to your fermented fruit, but stay away from powdered spices – they simply stick to the sides of the container and ruin the appearance of the fruit. This is especially important if you intend to give the jars of fermented fruit as a gift.
Store the fermented fruit correctly. During the fermentation process, the fruit container should be stored at room temperature, away from direct sunlight. Keep in mind that the unique conditions in your home will affect the success and speed of the fermentation process.
You can leave the fruit fermenting in the refrigerator during periods of warm weather, but keep in mind that this may interrupt the fermentation process somewhat.
When the fruit is completely fermented, you should store it in the refrigerator, where it will keep for up to two months. If you want, you can replace the fruit in that time – this will continue the fermentation process indefinitely.
Keep in mind that fermented fruits should have a nice acidic taste, but they should not taste like rotten fruit. They should not be shriveled either – fermented fruit should have its original shape. So if your fruit looks wilted or has a bad smell, you should throw that batch in the trash and start over.
Fermenting canned fruits
Choose the canned fruit. Open the can and drain the liquid from the fruit.
Put all the ingredients in a jar. Add equal amounts of sugar and the drained fruit in a jar with a slightly loose lid. Add a packet of yeast and mix well.
- Mix until the sugar is dissolved (the moisture from the fruit will liquefy the sugar). Add any flavoring and then put the lid on the jar.
- Leave approximately 2.5 cm of space at the top of the jar, as the volume will expand when the fruit ferments.
- The lid needs to be loose enough to allow the carbon dioxide to escape, but tight enough to prevent insects from entering the jar.
Let the fruit mixture sit in a dark, cool place. Fermentation occurs when bubbles appear in the fruit, because the yeast is digesting the sugar and converting it to alcohol.
- Fruit tends to ferment quickly, in 24 to 48 hours. However, some people prefer to ferment the fruit for up to 2 to 3 weeks. This will allow it to develop a stronger flavor as the syrup is converted to alcohol.
- How long you allow the fruit to ferment is a matter of personal preference. Try making several jars at once and letting each one ferment for a different length of time – this will help you find the “right spot” between not fermented, enough, and too fermented.
Fermenting fresh fruit
Make the fermentation syrup. When you are fermenting fresh fruit (as opposed to canned fruit), you need to make the syrup and let it ferment for several days before adding the fruit.
- Start making the syrup by mixing 1 cup of sugar with 2 cups of water and 1 packet of yeast in a jar with a loose lid.
- Mix repeatedly until the sugar dissolves in the water.
Let the mixture ferment for about 3 to 4 days. Replace the lid on the jar and let it rest at room temperature for 3 to 4 days.
- Watch for bubbles forming at the top of the jar – when you see bubbles, you know that the yeast is alive and active, and the fermentation process has begun.
Choose a fresh fruit to ferment. When the syrup mixture has been left to ferment for 3 to 4 days, you can add fresh fruit. See the section above for ideas of which fruits work best for fermentation.
- Use fruit that is fully ripe and spotless. Choose organic fruit whenever possible.
- Wash the fruit, remove the peel, large seeds or stones. Chop or slice the fruit into uniform pieces.
Add the fruit. Open the jar with the fermented syrup and add equal parts sugar and fresh fruit. Mix to dissolve the sugar.
- Congratulations – you have successfully finished fermenting the fruit. You can eat the fruit immediately, or you can replace the lid loosely and let the flavors develop for a few more days.
- This is also a good time to add other flavors, such as cinnamon sticks or vanilla beans.
Tips
- Add flavors to the fruit if you like with extracts, mint leaves, or cinnamon sticks. Do not use powdered spices, as they will stick to the sides of the jar.
- Certain fruits work better for fermenting than others. Blackberries have many seeds. Raspberries and strawberries tend to lose their color. Cherries need to be pitted to make them easier to eat when they are fermented. It is a good idea to peel and slice fruits like apricots, peaches, and pears before fermenting. Always use ripe fruit that has no stains.
- You can also make Rumtopf, or fruit fermentation with alcohol, by adding equal parts sugar and the fruit in a jar with a lid. Fill the jar with enough alcohol to cover the fruit and mix until the sugar dissolves. You can use rum, wine or cognac.
- You can also ferment frozen fruit. Let the fruit thaw and follow the instructions for canned fruit fermentation. Frozen fruit is an ideal choice for fruit that tends to lose its shape or color during fermentation, such as strawberries.
Pro Tips
- It is very important to leave the lid of the jar a little loose. If the carbon dioxide produced in the fermentation cannot escape, the pressure will build up and it will eventually explode.
- Remember, fermentation will cause expansion, so you should not fill more than 3/4 of the jar. If you do, the mixture will expand and overflow, making a huge mess.
- If the jar gets too hot, the yeast will die. If the jar gets too cold, the yeast will sleep. It needs to be at room temperature to keep the yeast active.
Required Materials
- Jar with slightly loose lids
- Canned, fresh or frozen fruit
- Sugar
- Yeast
- Water, if using fresh fruit
- Alcohol, if you are making a Rumtopf
- Flavors, if desired
