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 issues 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 the trickest 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 help the ferment go quickly.
- 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.
- Beverages will ferment 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. Aim for about 70 F / 21 C for kombucha and other probiotic sodas.
It’s not always possible to maintain the right temperatures. 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 of the cold. And 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 refrigerator works too.
Cleanliness is still important during storage. So don’t double-dip your pickle fork!
4. Avoid Cross-contamination between ferments
Fermenting cultures can cross-contaminate each other. For example, I’ve had milk kefir grow in my yogurt and kombucha SCOBY grow on my apple cider vinegar. 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!
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 7 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.
- Kahm yeast is a free-range yeast that isn’t dangerous. 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 a well-established wild yeast and bacterial culture 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.
Different Types of Fermented Foods
Are you ready to get fermenting? Here are some of the wonderful foods that are made through fermentation!
- Sparkling Beverages
- Sourdough Bread
- Sauerkraut, chutney, pickles and relish
- Beer, wine, cider and mead