
Fermentation is far from a perfect science. If anything, the exact opposite is true, two ferments seldom turn out the same. In fact, the subtle variations in flavour is one of the foodie joys of eating fermented foods!
Fermentation relies on a number of different variables including:
- exact combination of ingredients
- the fermenting culture
- indoor air-quality
- temperature
- and changes the weather.
However, there is a dark side to less than perfect ferments: A Fermentation Failure! (Cue the dark music.)
The most common problem for beginners is:
Fermentation didn’t start
Your sourdough never bubbles, your yogurt doesn’t set, your kombucha doesn’t grow a SCOBY, your beer doesn’t bubble, and you feel like giving up on fermentation. Luckily there are only a few reasons why fermentation didn’t start.
- Temperature: Ferments require an ideal temperature, anything outside of this temperature range slows down the ferment and can even stop it completely.
- Culture: The most common cause of culture death is heat. Accidentally stirring your yogurt into milk that is too hot will definitely kill your culture (it’s called sterilization and it works great at stopping the growth of bacteria!)
If you are maintaining a culture, it’s also important to feed your culture regularly, otherwise it will become less vital. This will affect your fermentation, but generally doesn’t stop the fermentation all together. Regardless it’s a good idea to give your culture a name and then feed it regularly! -My milk kefir is named Frank.-
- Water: If you use chlorinated water (some cities use chloramine) then that will harm your culture. The goal of chlorinating water is to prevent bacterial growth, and we want to encourage it! Unfortunately, simply passing your water through a charcoal filter isn’t always the best way to filter it. Here’s a whole post on filtering for fermentation.

- Air-quality: Many ferments rely on “free-range” yeasts and bacteria that live in your house. If you are a newbie fermenter, then your house might not have a lot of the right yeasts and bacteria, so you may struggle to get your ferments to colonize. Keep fermenting, then your local air quality will “improve” and you’ll find it easier and easier to kick start a ferment.
Another issue is if you use a hepe (or similar) air filtration system then you might not ever be able to colonize your ferments. Also, it’s a good idea to ease up on the anti-bacterial cleaning supplies. We need the right “bugs” in our environment to keep us healthy and help make great ferments!
- Time: It takes time to ferment… so give your recipes the time required to get going… sometimes it can take up to a week (or even longer) to finish a ferment.
For more information on Fermentation Failures check out Kahm Yeast and Mold and Fermentation Problems and Concerns. Also, feel free to post a comment below or on our Facebook page.
Hi,
I started make apple cider vinegar in October 20. Now i find out on the top of the vinegar white collar mod like a spider’s web. Unfortunately i can not attached the picture. Can you support me is it normal or not.
Thank you
Javid
I often get kahm yeast on my ACV. You can see a picture of it here: https://www.fermentingforfoodies.com/kahm-yeast-mold/ Does that look like what you have? It’s not a problem and will go away as the ACV becomes more acidic. Hope that helps!
Hi,
Thank you for your quick support.
Yes it looks like on you picture. I made the photo how can I send to you just to be sure.
Regards,
Can you send it to me on Facebook, Pinterest or Instagram?
Hello
Yes I can could you provide your Instagram info
Regards
Sure! You can find me at: http://instagram.com/readingfoodie/ I usually check it about twice a week, but I’ll look for your message today/tomorrow. Cheers!