What’s this on my cultured vegetables?

By On · 48 Comments · In Cultured Vegetables, Q&A
Cultured vegetables are so easy to make and almost foolproof with just a few exceptions. First of all, this is one of the safest ways to preserve your vegetables. It is scientifically impossible to get botulism from cultured vegetables. Here is a great video and post on this if you’d like further information. Fermenting Tip: Put a lid on it.
Kahm yeast on the sides of the jar.
Kahm yeast on the sides of the jar.
One of the things that people find most troublesome is what appears to be small areas of white mold growing on the surface of the cultured vegetables. There is no reason for alarm and it is not actually mold but a yeast that they call Kahm yeast. It can be found in cultured foods, but is not harmful. It can look scary and unpleasant, and even smell a little strong, but is not a harmful thing. It should be removed from the jar so it doesn’t impart a strong odor or unpleasant taste. If you can’t get it all removed and a little is left in the jar, it won’t hurt you.
This kind of thing almost never happens to me, so I spent some time this year trying to make this type of yeast appear on my vegetables to see if I could help you figure out why it happens. I have a lot of good bacteria and healthy yeast floating around my kitchen from years of fermenting and found it very difficult to reproduce this kind of thing on my vegetables. I really wanted to discover why this was happening to others and not to my ferments. Here is what I discovered from my many science projects.

Always use fresh vegetables

Fresh vegetables are key
Fresh vegetables are key
This seemed to be one of the fastest ways for this type of yeast to appear on the vegetables. I noticed it most when I used cucumbers and carrots from the store in the winter – when they had sat in my fridge for a while and I hadn’t used them right away. The sooner I used them and cultured them, the less chance I had of developing this Kahm yeast. Using fresh veggies seems to keep this from happening. If you don’t have a green thumb here are a few tips on how to grow tomatoes yourself!

Use a Culture

Caldwell Starter Culture For Vegetables is the best
Caldwell Starter Culture For Vegetables is the best
I almost always use Caldwell’s Starter Culture For Vegetables to culture my vegetables. It is the best veggie culture on the market and gives you tons of good bacteria – even more than using other starters or kefir whey. I met the people who made these starters and they shared graphs and charts explaining how their cultures worked. At first I was skeptical until I witnessed for myself how powerful these starters are. You don’t actually need a packaged culture starter to make cultured vegetables. Just adding salt, water, and submerging the vegetables under the  water will allow acidifying bacteria  to create an environment for the good bacteria to become dominant, creating billions of probiotics. But then, because there is no added starter culture, the bacteria are not as strong. When you add Caldwell starter culture, the bacteria stays at a higher level longer than other cultures and methods. Again and again I have witnessed the strength of these cultured veggies. Also, I have had very little trouble with this type of white film growing on my vegetables after I started using the Caldwell starter. I love it and will sing its praises. It is my very favorite veggie starter culture.

Keep the vegetables submerged under water

Fermentation causes veggies to float to the top of the jar.
Fermentation causes veggies to float to the top of the jar.
This is one of the ways to keep white Kahm yeast from showing up on your cultured vegetables – keep them submerged under the water where the good bacteria and acidifying bacteria keep this problem at bay. However, I’m gonna shoot straight with you. I never worry about this very much. My vegetables always float up above the water while fermenting and I get a kick out of watching them bubble up and rise. This bubbling means that little microbes are doing their job fermenting my food and I love watching it. It is a thrill to me that unseen forces are making my food powerful and mighty. So what I usually do when I see they are rising above the water is simply open the jar and push them down with a spoon. Then I close the jar and leave them to do their thing. I really don’t worry about it much because my veggies don’t mold very often, and I actually have to work at it to make them do this.

Reusing your brine for another culture

One other time I have seen Kahm mold was when I used the brine from Bubbies pickles to make a brine for some new cultured veggies. They almost always mold when I do this, because they don’t use added cultures and the bacteria are not very strong. Once you begin to culture your own vegetables, you absolutely can use the brine or juice from one cultured veggie to add to a new batch. But keep in mind that over time the levels of good bacteria diminish so this can cause it to develop the Kahm yeast.

Making your vegetables in an airlock vessel

Airlock jar
Airlock jar
This can also help with any Kahm yeast and is very effective but not foolproof. If your veggies aren’t fresh or your culture isn’t strong enough there can still be problems. An airlock vessel gives you less problems than other vessels. The vegetables seem to be protected better from exposure to air which can cause the vegetables to turn brown or develop a white film.

Temperature

Letting them ferment in a cooler temperature is helpful. Cultured vegetables like it a little cooler – between 63 and 80 degrees Fahrenheit. If they do get Kahm yeast on them, simply scrape it off and place them in the fridge. The cooler temperature can often cause the yeast to stop developing.

Time and salt

Only ferment your vegetables the minimum recommended time on your counter, which is six to seven days for cabbage ferments and three days for other veggies like pickles, tomatoes, and carrots. Adding salt also inhibits the growth of undesirable pathogens, including yeasts and other microorganisms. Too much salt won’t allow lactic acid fermentation to occur fully, but too little salt can result in off flavors or mushy vegetables.
So there you have it – my science experiments to help you out with your problems and make it as easy as possible for you. I am at your service when you need my help. Even if it means destroying perfectly innocent vegetables for the sake of science.
P.S. I also hate posting ugly pictures of imperfect cultured vegetables. These are the things I do for you…..

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Log into your YouTube account, then go to http://www.youtube.com/user/CulturedFoodLife and hit the red “Subscribe” button.
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Blue vintage jars with cultured veggies
Blue vintage jars with cultured veggies

Biotic Pro Winner:

The winner of the Blue Vintage Ball Jars, stuffed with my cultured vegetables is Jan Johnston. Please contact me at donna@culturedfoodlife.com and your cultured veggies and jars will be on their way to you.