The fermentation step is optional, but it helps reduce natural sugar and really enhances the nutritional value of the fruit. Most importantly, fermentation adds an undetectable probiotic twist that is well worth your extra time.
If you’re new to fermenting, don’t be put off; the process is very simple. The waiting is the most difficult part. Fermenting fruit takes up to 3 days, plus 24-hours drying, so clearly, these are not an instant snack. Once they are done however you have a delicious, take anywhere, healthy, mess-free, probiotic snack option up your sleeve.
Note about fermenting jars: You don’t need fancy equipment to start fermenting. However, investing in a good quality jar is important. I recommend ‘Fido’ jars that are sold at good department / kitchenware stores. These jars are made from tough, lead-free glass and have a good quality rubber seal that can ‘off-gas’ during fermentation. Don’t be tempted to use the cheap imitation jars, that look similar, sold from discount stores. They produce unreliable ferments and have been known to explode. (but don’t let this scare you!)
1. Pour boiling water into your fermenting jar and swish around to ensure it is sterile then discard the water. Set aside.
2. Peel the apples and chop into small chunks.
3. Process the apples and blueberries in food processor until you achieve a smooth puree. Depending on the strength of your machine, this may take up to 5 minutes.
4. Transfer the fruit puree to the fermenting jar always leaving at least an inch of headspace at the top.
5. Add the whey, water kefir or starter culture and thoroughly mix in. (I used a vegetable started culture.) Learn how to drip whey from yoghurt here.
6. Lightly tap the jar on the bench to pack the fruit in and reduce the air bubbles.
7. Fasten the lid and leave to ferment away from direct sunlight for 1-3 days. Exact timing depends on the temperature of your house. An ideal fermenting temperature is approx. 20° Celsius — less time will be needed in temperatures above 24° Celsius. Note: In hot weather, (over 30° Celsius) fruit ferments can quickly convert to alcohol so only culture for a short period of time. What you’re after is a smell and taste that is slightly tangy and sweet, there should be no sour, pungent, or ‘off’ smell.
8. Once your fruit has fermented, it is ready for dehydrating. To halt the fermentation, you may also store the jar in the refrigerator until required. It should keep for 1-3 months. Let your nose be the judge.
9. Strain the fermented fruit with a wire sieve to reduce the liquid content and thicken up the puree. Do not throw this probiotic goodness away. Chill and drink straight up or add to smoothies - your kids will love it!
10. Spread the fermented fruit mixture onto 2 x fruit rollup sheets. Use the lip of the rollup sheet as a thickness guide. 5 mm thick produces the best results.
11. Place the trays into the dehydrator trays, stack and put the lid on
12. Set the dehydrator at speed 2 (this is approx. 42° Celsius)
13. Leave to dehydrate for around 24 hours. Your batch may require slightly more or less time depending on the moisture in the mixture.
14. When the fruit easily peels and is not sticky, it is done. Sticky areas may be put back into the dehydrator for further drying.
15. Cut the fruit roll-ups into strips. I find scissors are easiest.
16. Store in a cool place, sealed in a glass container or jar for several weeks. In warm weather, probiotic fruit roll-ups will need to be kept in the fridge.
If you enjoy this recipe, you might also like to try probiotic berry and coconut yoghurt rollups.