How to Know When Your Fermented Vegetables Are Ready for Cold Storage


To the new fermenter every step of the fermentation process can be a bit intimidating. From trusting that the fermentation will in fact keep your vegetables from spoiling without a boiling water bath to braving the first bite, everyone needs a little help in the kitchen when tackling this traditional way of preserving food.

One of the biggest questions people have is “How do I know when my fermented vegetables are done?” By this they mean “How do I know that my vegetables are fermented?”

This is a complicated question to answer because the process of fermentation never really ceases unless you either freeze it (which almost completely halts the process) or cook it (which kills the bacteria that are performing the fermentation process).

Historically, vegetable fermentation often took place in root cellars or buried vessels which meant the whole process was slowed down in comparison to many of today’s fermentation recipes which call for “3 to 10 days of fermentation and then move to your refrigerator.”

So where the old method of vegetable fermentation relied on underground storage for both the fermentation period and the storage period, the new method usually recommends a fast fermentation at warmer temperatures followed by a possibly overly cold storage period.

So to answer this question we must clarify that this is in reference to the latter practice in which a short fermentation period is done at warmer (room) temperature followed by a colder (refrigerated) storage.

Please note, however, that in either case the fermentation process is continual and flavors will change over time. Generally your cultured vegetables will taste different when first placed into cold storage than they do after several months of storage. This is because the microorganisms continue to do their work on the sugars and other carbohydrates found in the vegetables.

There are three obvious signs that the fermentation process has at least commenced enough that you can now move your fermenting vegetables to cold storage.


The lactic acid fermentation process produces lactic acid bacteria that create gases when they feast on the vegetables you are fermenting. These bubbles are often visible after a few days at room temperature and are a good sign.

In largely chopped vegetables like chunks of zucchini, the brine will contain bubbles and the vegetables themselves will only have a slightly “bubbly” flavor. Other ferments that use vegetables with more surface area, like a salsa, will have an almost carbonated flavor throughout.

This is normal and good and quite tasty as well once you realize  arbonation is an indication that the lactic acid bacteria are doing their job, producing acids that will preserve the food. If you see those bubbles you have at least one indication that your vegetable fermentation is well underway.


“The nose knows” is very true when it comes to fermentation. If you open your fermentation vessel after a few days wondering whether your sauerkraut has begun to sour you will be bombarded with interesting odors one way or another.

If your sauerkraut smells sour and fermented; then you’re in business. If, on the other hand, your sauerkraut smells downright rotten, nasty, or putrid then you will want to throw it on the compost heap and begin again.

Once there is a definite fermentation odor about your vegetable ferment you will know it is on its way to cold storage status.


Finally, once you know the vegetable ferment appears gaseous or bubbly and does not smell rotten, you will want to give it a taste. Depending on the type of vegetable ferment you have performed you may find varying ranges of fermented flavors.

A large vegetable that has been placed in a brine, like a cucumber pickle, will take a much longer time to fully take on that fermented tangy flavor so typical of fermented vegetables. A mashup of small vegetable pieces that create their own brine through weighting and salt, like sauerkraut, will most likely take on a fermented flavor more quickly.

Temperature also plays a role in how quickly you will notice bubbles, smells, and flavors of fermented vegetables. The higher the temperature, the quicker the fermentation process will go. So in a warmer climate you may very well want just a couple of days at room temperature before moving the vegetables into cold storage. In cooler climates, however, it could take a week or longer to produce obvious signs of fermentation.

There will be a sweet spot in between the “just began fermenting” stage and the “oops now my vegetables are mush” stage. Based on the above three signs and the temperature of your fermentation area, give your ferments 2 to 3 days beyond the starting stages of fermentation for a cooler climate and 1 to 2 days in a warmer climate before moving the ferment to cold storage.

So trust your instincts, let your nose do the telling, and be confident that you will know when fermentation is taking place and when you have lost your vegetables to bad bacteria.



Sauerkraut in Glass Jar

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