Fermented fruits can be an excellent gift for your family and friends. You can use the fruits to flavor alcoholic beverages or to put them on top of your favorite dessert. Yeast breaks down the sugars in fruit during the fermentation process, and you can use any type of fruit you like, although some are better than others. Follow these steps to learn how to ferment fruit, whether fresh or from a can.
Part 1 of 3: Understanding fermentation
Step 1. Know what fermentation is and why it is good for you
Fermentation is a process used to preserve food and increase the level of good bacteria it contains. You shouldn't be intimidated by the fermentation process – it's actually quite simple and straightforward!
- Basically, fermentation involves placing a fruit of choice in a jar or other container and adding a combination of water, sugar and a culture (such as yeast or whey).
- Then you put the lid on and the fruit is left at room temperature for 2 to 10 days. During this time, the culture will convert the sugar to alcohol, and carbon dioxide will be produced as a by-product, forming bubbles at the top of the jar.
- When fermented, the fruit will contain an abundance of beneficial bacteria and can be used as a condiment, dessert topping or in recipes for things like chutney, smoothies and sauces.
Step 2. 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 cuts down on preparation time. If you are using fresh fruit, choose an organic, ripe product with no blemishes.
- Fruits such as peaches, plums and apricots are popular choices for fermentation because they are tasty and keep their color well. Wash fruit, peel and remove any pits.
- Exotic fruits like mangoes and pineapples ferment well and can be used to make chutney. Remove the husk and cut evenly sized cubes before using.
- Grapes can be fermented, but they must be picked with a needle or cut in half 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 don't find appealing).
- Most berries can be fermented, except for blackberry, which doesn't contain many seeds. Strawberries ferment well in terms of flavor, but syrup tends to strip them of color.
Step 3. 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 cultures (mainly for fermenting fruits rather than vegetables) are yeast, whey or powders from starter cultures.
- However, you can also use an open probiotic capsule, 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 brandy is used to stimulate fermentation.
Step 4. Add some flavor
In addition to the fruit flavor, you can add other flavors to the container to add 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 fruit's appearance. This is especially important if you plan to give the fermented fruit jars as a gift.
Step 5. Store the fermented fruit correctly
During the fermentation process, the fruit container must be stored at room temperature, away from direct sunlight. Keep in mind that your home's unique conditions will affect the success and speed of the fermentation process.
- You can leave the fruit to ferment in the refrigerator during periods of hot weather, but keep in mind that this can interrupt the fermentation process a bit.
- When the fruit is fully fermented, you should store it in the refrigerator, where you will keep it for up to two months. If you like, you can substitute the fruits at this time – this will continue the fermentation process indefinitely.
- Keep in mind that fermented fruits should have a pleasant sour taste, but they shouldn't taste like rotten fruit. They shouldn't be wilted either – fermented fruits should have their original shape. So, if your fruit looks wilted or smells bad, you should throw this shipment in the trash and start again.
Part 2 of 3: Fermenting Canned Fruits
Step 1. Choose the canned fruit
Open the can and drain the liquid from the fruit.
Step 2. Place all ingredients in a jar
Add equal amounts of sugar and the drained fruit into 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 flavor and then place 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 keep insects out of the jar.
Step 3. Let the fruit mixture sit in a cool, dark 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, within 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 amount of time – this will help you find the "right spot" between not fermented, enough and heavily fermented.
Part 3 of 3: Fermenting Fresh Fruits
Step 1. Make the fermentation syrup
When you are fermenting fresh fruit (as opposed to canned fruit), it is necessary to make the syrup and leave it to ferment for several days before adding the fruit.
- Start making 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 sugar dissolves in water.
Step 2. Let the mixture ferment for about 3 to 4 days
Replace the lid on the jar and let it sit at room temperature for 3 to 4 days.
Look for bubbles at the top of the jar – when you see them, you'll know the yeast is alive and active and the fermentation process has started
Step 3. Choose a fresh fruit to ferment
When the syrup mixture has been left to ferment for 3 to 4 days, you can add the fresh fruit. See the section above for ideas on which fruits work best for fermentation.
- Use fruits that are fully ripe and unblemished. Choose organic fruits whenever possible.
- Wash fruit, remove skin, large seeds or pits. Chop or slice the fruit into even pieces.
Step 4. Add the fruit
Open the jar with the fermented syrup and add equal parts of sugar and fresh fruit. Mix to dissolve sugar.
- Congratulations – you have successfully finished fermenting the fruit. You can eat the fruit right away, 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 like cinnamon sticks or vanilla beans.
- 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. Wild blackberries have many seeds. Raspberry and strawberry tend to lose color. Cherries need to be pitted to facilitate eating when they are fermented. It is a good idea to peel and slice fruits such as apricots, peaches and pears before fermenting them. Always use ripe fruit that has no stains.
- You can also make Rumtopf, or fruit brew with alcohol, by adding equal parts sugar and 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 brandy.
- You can also ferment frozen fruit. Let the fruit thaw and follow the instructions for fermenting canned fruit. Frozen fruits are an ideal choice for fruits that tend to lose shape or color during fermentation, such as strawberries.
- It is very important to leave the jar lid loose. If the carbon dioxide produced in fermentation cannot escape, the pressure will build up and will eventually explode.
- Remember, fermentation will cause expansion, so you shouldn't fill more than 3/4 of the jar. If you do, the mixture will expand and spill over, making a huge mess.
- If the jar gets too hot, the yeast will die. If the jar gets too cold, the yeast will go to sleep. It needs to stay at room temperature to keep the yeast active.