Want to learn how to ferment? Here are five simple rules for success, whether you want to ferment vegetables, dairy, sourdough, or beer!
1. Keep everything clean
It is important to keep jars and kitchen utensils as clean as possible to prevent contamination from unwanted bacteria, yeasts, and molds. This is even more important if you’re planning on keeping your ferments for longer than a week.
- If it’s a quick ferment and you’ve never had issues with contamination, then it’s probably fine to use jars that have been well washed.
- Always sanitize if you’re making anything that is going to ferment for more than a week.
- If you’ve had an issue with mold or kahm yeast, then sanitize.
- The easiest way to sanitize is to pour boiling water over everything. However, I recommend using commercial sanitizers for ferments, like beer, wine, and cheese.
Want more info? Here is a post specifically on how to clean and sanitize for fermenting.
2. Ferment at the Right Temperature
Fermenting at the right temperature is a good way to make sure that everything ferments at the optimal rate.
- Grain likes to ferment at 70F / 21 C. So stash your sourdough and other grain ferments near your hot water heater or above the fridge.
- Vegetables like to ferment at 63F / 18 C. Garages and basements are perfect for vegetable ferments. If you’re an urbanite… stash your vegetables in a cool-ish closet away from any heaters.
- Probiotic sodas like 70 F / 21 C. Sodas like kombucha, water kefir, and ginger bug will ferment very quickly at warmer temperatures, then slow down if it’s cool. The temperature will make the difference between your soda being ready in 24 hours (hot) to 5 days (cold).
- Alcoholic beverages range between 60 to 78F / 15 to 25 C. The ideal temperature will depend on the exact strains of yeast. In general, I recommend reading the yeast packages for beer and wine.
It’s not always easy to maintain the right temperature for fermentation. Don’t worry, just keep an eye on things and adjust the culturing time, as necessary. For example, in the winter, sourdough might need to rise for an extra few hours because it’s cold. In the summer, sauerkraut might be finished fermenting within a few days rather than weeks because of the heat.
3. Storing Ferments
Once you’re done fermenting, always store your ferments somewhere cool. This will slow down the fermentation and increase the shelf-life. Traditionally fermented foods were stored in a cellar or cold room, but the back of your refrigerator works too.
Cleanliness is still important during storage. So don’t double-dip your pickle fork!
4. How to avoid Cross-contamination between ferments
Fermenting cultures can cross-contaminate each other. For example, I’ve had milk kefir grow in my yogurt. And I’ve found that probiotic sodas can interfere with my sourdough.
- If you plan on keeping several different types of cultures, don’t have them sitting next to each other while fermenting. The easiest way to prevent this is to keep your ferments in different closets or rooms.
- Keeping ferments separated is more important for wild cultured ferments, like sourdough, ginger bug, etc.
- It’s fine to have all your pickled vegetables in the same location. Or to store wine, cider, and beer in the same location. Just don’t mix your dairy cultures… they will definitely cross-contaminate.
5. What to do if something is bad?
Fermented foods should never look or smell bad. It’s really quite rare to have a ferment go bad. In my many years of fermenting, I’ve had to throw out about 5 things… and I make about 10 different ferments a week!
Here are a few pieces of advice to help you avoid having a ferment go bad.
- Mold cannot grow in salt brine. That’s why fermented vegetables need to be kept below the salt brine. If there is mold on the surface of the brine, it can safely be removed without having harmed the fermented vegetables. Here’s a brine calculator to help you make sure your brine is salty enough.
- Kahm yeast is a free-range yeast that isn’t dangerous. It forms a thin layer across the top of a ferment. Wondering if you have kahm yeast? Here’s a post on the difference between mold and kahm yeast.
- If you have issues with mold in your house or you live in a heavily polluted city, it can be difficult to get started with wild ferments. Stick with store-bought cultures until you’ve got well-established wild yeasts and bacterial cultures in your home.
- The best way to keep the wrong kinds of bacteria, yeasts, and molds out of your ferments is to follow a good recipe. Healthy, vigorous cultures (whether it’s a kombucha SCOBY, sourdough starter, or jar of sauerkraut) will naturally out-compete any microbe that might cause it to go off. It’s why fermentation is such a great way to preserve food!
- If you are ever in doubt, throw it out.
Looking for some more advice?
There’s so much to know about fermentation. However, I want to assure you it is EASIER THAN YOU THINK.
There are really only three steps:
- Follow a tried and tested recipe. (All recipes on Fermenting For Foodies have been tested numerous times).
- Be patient. Fermenting always takes a bit of time to let the microbes do their thing.
- The ferment is done when it tastes good! That can be really quick (12 hours) or take up to several weeks. The exact timing is up to you. There are no wrong answers.
Feel free to check out all of the topics in the Fermenting Basics category. There’s a lot there!