How to Ferment: 5 Steps for Fermenting Success!

Want to learn how to ferment? Here are five simple rules for success, whether you want to ferment vegetables, dairy, sourdough, or beer!

I started Fermenting For Foodies in 2014. Since then, I’ve tried fermenting pretty much EVERYTHING! I love it!

• It’s a super easy way to prepare and preserve food (pack it in a container and you’re done)!
• Homemade fermented foods are a great source of probiotics.
• They are simple and delicious.

If you are new to fermenting, here are a five rules to make sure that all your ferments are a success!

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 jars.
• The easiest way to sanitize is to pour boiling water over everything.
• I recommend using commercial sanitizers for ferments that require a particular culture, like beer, wine, and cheese.

Want more info? Here is a post specifically on how to clean and sanitize for fermenting.

2. What Temperature For Fermenting?

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, and slow down when 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 package to determine the best temperature for homemade beer or 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 finish 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!

Here is a post with more details on where you should store fermented foods both during fermentation and for the long term. And a post on the typical shelf-life of fermented foods.

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, avoid having them sit 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 container should you use?

When most people think of fermenting, they think of a jar of sauerkraut, kimchi, or pickled green beans. However, there are so many different kinds of ferments that one-jar doesn’t work for them all!

Here are a few suggestions:

• In general, I prefer glass. It is non-reactive and won’t flavor the food. This is true whether I’m making sourdough starter or beer.
• If you are using plastic, don’t swap the container for a different type of ferment… no one wants dill pickle flavored yogurt!
• When you’re just starting, it’s fine to use whatever you happen to have in your kitchen. As you become more experienced, you will naturally get more supplies: airlocks for wine or fido jars for pickles.
• If you’re looking for more details here’s a post on containers for fermented vegetables.

What should you do if something is bad?

Fermented foods should never look or smell bad. It’s 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 a lot of fermented food

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:

1. Follow a tried and tested recipe. (All recipes on Fermenting For Foodies have been tested numerous times).
2. Be patient. Fermenting always takes a bit of time to let the microbes do their thing.
3. 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 of information in there!

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
• Cheese
• Sauerkraut, chutney, pickles and relish
• Beer, wine, cider and mead
• Miso
• Tempeh