Wild fermentation is living food. Naturally you will be insecure in the beginning. Is this white film on the vegetables edible? Or has the ferment gone bad? Is the brine supposed to become cloudy like this? Or, even worse, first cloudy and then clear again?
Don't get confused and believe me, fermenting is really easy! And the best thing is: Not everything that may seem so at first glance is a mistake when fermenting.
My 3 top tips for fermenting beginners
- Follow recipes
Someone has successfully fermented something and made the effort to write it down. Chances are high that you can reproduce it. Creativity and room for own ideas comes with experience.
- Read up - and ask questions!
To whom? The person whose recipe you follow or whose instructions you read is always best. On this page, for example, it's easy to do this using the comment function at the bottom of each page.
- Under the brine is fine
Always make sure your ferment is under the brine. And then relax. You will learn everything else over time.
Wild fermentation is easy!
Simple instructions and even more essential background knowledge can be found in the articles on fermentation of vegetables and fruits.
Wild Fermentation FAQ
These are the questions I am regularly asked about the wild fermentation of vegetables.
How much salt is needed for wild fermentation?
Basically, the fermentation of e.g. vegetables works also salt-free. However, the addition of salt helps to prevent the growth of undesirable microorganisms. Unlike most other microbes, the good lactic acid bacteria can also multiply in a salty environment and controlled fermentation takes place. With a salt content of 2%, most of the cultures work absolutely fine.
During the summer, you can use more salt to slow down the fermentation process, which is accelerated by the heat. The more salt, the slower the fermentation gets going.
Salt also helps to maintain the crunchiness of vegetables, besides the ferment becomes more acidic. I prefer to make sour gherkins with 5% brine. Since pickling cucumbers are in season in the summer, this of course also has to do with temperature equalization.
If the salt content exceeds 10%, it is called pickling, because such a high salt content excludes the microorganisms necessary for lactic acid fermentation.
What is the right temperature for my ferment?
Temperature plays an important role in the fermentation process. Between 18° and 24° C the lactic acid bacteria work best. The warmer it is, the faster the fermentation process starts. If your home gets very warm in summer, you can help the bacteria by increasing the salt content. With more salinity the process takes longer and creates better conditions for a successful and safe fermentation. After one week I put my vessels a little cooler, between 18° and 20°. I leave them there until they are ready. Above 25°C it will be too warm, then the lactic acid bacteria can no longer properly do their work.
Do I necessarily need a fermentation weight?
No. You don't need a special fermentation weight.
Period. Exclamation mark!
Nevertheless, weights make fermenting much easier and cleaner, because the jars don't have to be filled so high that the brine will overflow. That's why I almost always use something to hold the fermenting food under the brine, and most of it is simply re-purposed stuff from my household..
The vegetables or herbs float over the brine!
Especially with shredded vegetables or herbs, it can happen that parts of them bypass the weight and float over the brine. If that happens on the first day, you just open the jar, pack it well and close it again. If the fermentation is already well underway, the floating of smaller particles is usually not a problem because the oxygen has already been pushed out and without oxygen mold won't grow. In this case, however, you should by no means open the glass to maintain the oxygen-free environment!
In the period between the first few hours and the elimination of the oxygen by the advancing fermentation, there is a great chance that the ferment will become mouldy.
So the goal is that nothing gets above the brine. It is best to always place the smallest parts at the bottom of the glass and layer larger ones as a barrier above. Large cabbage leaves, for example, seal the fermentation material well at the top, or cleverly overlapping weights. Glass lids of preserving jars are very suitable for this purpose - they are handy in size and so cheap that you can buy several. Herbs are best used fresh and left whole.
What's the ideal filling height in the fermentation vessel?
The vegetables or fruit must be underneath the brine! Leave 3-5cm (or approx. 2 fingers wide) of space to the upper edge of the container. More space to the top means more oxygen in the jar, and that is risky. If the fermentation doesn't get going fast enough to displace the oxygen by transforming carbohydrates to carbon dioxide, you'll be dealing with mold in the worst case, and mold is toxic. Better use a smaller vessel if you notice that there is too much air up in your jar.
On the contrary, if you make the vessel too full, it can overflow. Fortunately, this is not at all harmful to your health - but it may damage your furniture. It is best to place a bowl or plate under your fermentation vessels until you get the hang of the filling level.
In March 2021 I posted a story highlight on my instagram profile about the perfect fill height, stop by and check out my tips!
The vegetables keep rising up. What should I do?
When fermentation starts, carbon dioxide is produced. The small bubbles push some vegetables upwards. With sauerkraut or other grated vegetables, this happens quite often. Most of the time, the carbon dioxide has already displaced the oxygen in the jar, so even if the vegetables move over the brine, you should not have any problems. You can even test the carbon dioxide content yourself! To do this, simply fiddle a bit with the rubber seal - if it fizzes, there is enough carbon dioxide.
What if the brine overflows?
So the fact that the fill level increases is in the nature of things. If you have not left enough space to the top, or the vegetable has many available carbohydrates and is therefore more active, the fermentation glass may overflow. Then you need to put something underneath and wait until the active phase is over. And remember to leave more head space next time 😉
Wild fermentation and brine - cloudy or clear?
I am always happy when the lake becomes cloudy. The cloudiness of the brine is an unmistakable sign of lactofermetation taking place and is caused by the dead cell walls of the lactic acid bacteria. Often the brine becomes clear again after some time. This confused me at first, but it is quite logical. The floating particles had enough time to settle on the bottom or on the fermenting product and the brine becomes clear again.
The brine is foaming! The brine is bubbling? The brine does not change at all!
Take a breath. This is all normal. Phew. It's not called wild fermentation for nothing.
Some vegetables bubble and foam more than others. This is related to the carbohydrate content. The more carbohydrates are available, e.g. in beet, carrot or Jerusalem artichoke, the more fermentation occurs, which can be accompanied by foaming and strong carbonic acid development.
If, on the contrary, the ferment does not seem to get going at all, there are either too few carbohydrates (good tip: an extra onion helps taste and fermentation!), it is too cold or too much salt was used.
Otherwise, as long as the ferment smells and tastes good, there is no need to worry.
What is the white coating on my ferment? And is the white buildup on the bottom of the jar bad for you?
No. The white coating is simply the dead cell walls of the lactic acid bacteria that settle on the vegetables and/or the bottom of your container after some time. If it is visually disturbing, you can simply wash off the coating before eating. In terms of taste, it makes no difference.
Which vegetables are suitable for fermentation?
Cauliflower, broccoli, beans, bananas, wild garlic? Basically, yes. Any vegetable can be fermented - white cabbage, carrots, chili, beet, celery, cucumber, watermelon rind, peppers, green tomatoes... The only vegetables I don't recommend fermentation for are those with a lot of chlorophyll, like kale or spinach. Solo ferments from herbs are also a challenge. It's best to find out for yourself. And if you've done a really good experiment, please tell me about it and drop me a comment or an email. I just love to learn something new!
Why do fermented carrots or cucumbers become so soft?
Vegetables become softer during fermentation anyway. The longer you let it ferment, the softer it will become. However, the fact that your ferment becomes much too soft for your taste can have various reasons. Which reason applies in your specific case, you will find out yourself with the help of my explanations.
If your carrots have been stored for a long time, they will not stay as crisp as very fresh carrots. In the same way, soggy turnips will not miraculously become fresh again when you ferment them.
Vegetables such as cucumbers, zucchini or other very watery vegetables need active support to keep them crunchy. That is why tannins are added to the ferment. Tried and tested are either a piece of fresh horseradish, vine leaves, currant leaves or even cherry leaves. Just take what you find while shopping, in the garden or in the park. Maybe not necessarily from the side of busy roads.
Temperature & Salinity
As described at the beginning, the warmer it is, the faster the fermentation gets going and the more vigorously the ferment ferments. This can also make the result softer. Salt helps preserve the crunchiness of vegetables by slowing down the fermentation. I prefer to make pickled cucumbers with 5% brine. I don't suggest wild fermentation without added salt.
With beet , most questions reach me about when the ferment softens, or why the beet is still hard after a long fermentation period. Sometimes there are genuine reasons, such as the beet was cut too coarsely or the salt content and temperature were not ideal. But often the reason is simply your expectations. Of course, your homemade ferment will not taste the same as store-bought pickled beet, because a pickled product is not a fermented product.
And why does sauerkraut sometimes remain hard?
This can have two reasons. Either the reverse reasons from above - i.e., you used too much salt or the initial temperature was too low - or you were too comfortable and simply did not knead enough 😆
How can I tell if the ferment has gone bad?
The ferment is all slimy, can I still eat it? What is this white skin on the brine, is it kahm yeast? What is kahm yeast anyway and is it harmful to your health? Can I just skim off the mold and eat the rest???
These are all very important questions that you will soon be able to recognize and correct yourself. So that this page does not become too long, you will find common mistakes and how to avoid them on an individual page.
What is the fermentation time of sauerkraut? How long should carrots be fermented?
The fermentation time varies depending on the vegetable, temperature and type of ferment from three days to three months or more (my oldest miso has already celebrated its 3rd birthday, garlic in honey has also sometimes had 4 years fermentation time 😆 ). The only true clue to know when your ferment is ready is your taste. With time, you'll figure out what tastes best to you. Until then, feel free to follow the suggestions in my recipes.
How should I store the final product?
When the fermentation is finished (you like the product and it doesn't carbonate any more), you should cool the vegetables and the brine at 4° - 8°C. In the cold, the fermentation is slowed down until just before it stops and the taste is preserved without the valuable ingredients being destroyed by boiling or other types of sterilization. The finished product can be kept in the refrigerator for months.
If you do not have enough space, you can also transfer the ferment into screw glasses. However, any contact with oxygen carries the risk of contamination with mold spores, so it is important to pay special attention to cleanliness when the fermented products are ready.
How hygienic do I need to be when fermenting?
For fermentation you should also have some experience in handling food, for example the basics of kitchen hygiene. The vessels used should not be sterile, but must be clean. The lactic acid bacteria from the environment do help in the fermentation process.
Ideally, you should open the jar for consumption. Opened ferments must be kept cool and used as soon as possible. And please do not reach into the glass with your fingers, but use new, clean cutlery each time.
Are fermented foods healthy?
Fermented foods not only have culinary advantages, they also contribute to a diverse diet. The microorganisms produced during fermentation have a positive effect on the microbiome, the pool of good bacteria in our gut. This also has a positive influence on the immune system. In addition, the intake of raw wild ferments and cultivated food improves digestion.
The bacteria that help in the fermentation process digest (metabolize, transform) the vegetables for us, making them easier to digest. Wild fermentation is also called fireless cooking.