How Long To Ferment Sauerkraut?

How long does it take to ferment sauerkraut in a crock or mason jar? I guess the answer you're not looking for depends!

But to put you out of you're misery, sauerkraut fermented under ideal conditions, ideally in a ceramic water-sealed fermentation crock like these should take around 20 days to develop a full flavor and be ready for eating. This is dependent of a few stars aligning, which I'll discuss in this article.

Good things come to those who wait is the old adage. Not quite sure who said it, but it rings true in many aspects of life. Work, promotion, family, food, wine and of course, Sauerkraut.

Like an aged Whiskey or a well-hung (ooohhhh Missus!!) haunch of Venison, fermented vegetables improve with time to some extent.

Plenty of Korean people love their Kimchi when it's at least 3 years old.  They bury large pots full of the stuff in the ground where the temperature is actually quite stable.

The flavors have time to develop, little nuances appear that the taste buds would struggle to perceive in a 2 week old batch. As our fermented products gain a little age, we delight in our ability to discover a richer flavor.

More tangy, slightly more sour than before? A deeper taste that tantalizes our searching taste buds.

On top of that, fermented foods like sauerkraut are live, raw products, brimming with healthy bacteria. Time is a friend to bacteria, allowing them to multiply, their numbers exploding from thousands to trillions in a single jar. Dirty rascals!

If we are making our our kraut, as we all should be, we want the fermentation process to allow our vegetables to develop its fullest potential, in both flavor and nutritional density right? So how long should you ferment your sauerkraut for, and how long might be too long?

A calendar is useful to time how long you need to ferment your sauerkraut for

All things being equal, the fermentation process is extremely aligned with temperature, salinity and acidity. It makes sense really. A very low ambient temperature slows down fermentation as the microbes become dormant.

Higher temperatures cause them to become more active, to reproduce more, and to make pigs of themselves on those sweet sugars being released from the vegetables.

In perfect conditions, around 65 degrees, your sauerkraut should take around 3 weeks to ferment.

The Ideal Temperature For Fermentation


The ideal temperature for fermenting sauerkraut is between 55-75 degrees Fahrenheit. Aiming for 65 deg F with a temperature fluctuation of no more than 5 degrees in either direction ensure a nice even fermentation. At the lower temperatures, the fermentation process becomes slower, and the sauerkraut retains more or a crunch. It also allows the cabbage to develops great flavor.

Using a ceramic fermentation crock can really help to maintain a narrow temperature range.

Giving your kraut a bit of a kickstart by fermenting it closer to the top end, 75 degrees, can get the process going nicely. A couple of days here, then drop it back to something close to 65 degrees and you're all set.

Some impatient folks attempt to make sauerkraut to fast by leaving it at far too high a temperature. The fermentation of sauerkraut  definitely works best without any dramatic variations in temperature.

Many people live in houses where a wood stove or some other relatively uncontrollable heating method makes it difficult to maintain a steady temperature. This is not good for sauerkraut production.

In this situation, I would find a cool place, a cellar or even a garage, and heat it with a small tubular heater or a small oil-filled radiator like this one on Amazon. Being thermostatically controlled, you can just maintain a room to be ideal for fermentation.

Of course, if you're garage goes sub-zero during the winter, you're going to need to think again. Most people can find somewhere suitable. Certainly not a hurdle that can't be overcome.

Effect Of Acidity On The Fermentation Process

The fermentation process, in which a variety of bacterial strains chomp away on the sugars that are released from the cabbage. Their waste product is lactic acid. Interestingly, at the ideal temperature of 65 deg F, those bacteria ferment in a sequence.

Luckily, this sequence produces the highest quality kraut....yippeeee! To learn more about this amazing natural sequence, I'd highly recommend this article.

How Much Salt For Sauerkraut Perfection?

Salt for sauerkraut and fermenting

Salt and salinity play a large role in perfect fermentation. Sometimes it takes a little tweaking but a good rule of thumb is:

> 1 tablespoon of salt to 2 lbs of cabbage for perfect sauerkraut

A medium sized head of cabbage weighs around 2 lbs, but I always weigh it after I've removed the outer leaves and cored it. Read my article on how to make sauerkraut in a fermentation crock if you want an in-depth tutorial on the process.

If you end up with overly soft or slimy kraut, too much salt may be the issue. Under normal circumstances, their is some leeway, but too much salt combined with a high room temperature can be a recipe for something yucky.

Want More Salt Info? Read this:

What Is The Best Salt For Fermenting

Finally.....It's All About The Taste

Whatever the fermenting gurus say (I'm not one by the way, but I've been making this stuff a long time), your own personal ability and taste matter, and should be the over-arching metric on how long you ferment your kraut for. Check this useful resource on how to make naturally fermented foods, in which I cover many of the questions you may have about getting started.

Taste it after 7 days. Is it still crunchy, is it tangy or sour enough for you? If so, then get it out of that crock or mason jar and into storage jars in the refrigerator. If it's not quite their, graciously replace the lid and leave it a few more days before you test again.

There's little more to it than that. Aim for the right salinity, the right temperature, and the right duration (remembering to test along the way) and you'll be fine.

Slimy sauerkraut, fluffy of fuzzy mold and it's game over. Throw it and begin again. Keeping the air out is important, so I like fermenting  sauerkraut in a water sealed fermentation crock. but jars can work fine too.

That's it. Hope this has helped and given you some confidence to get fermenting.

Here's to kraut success!

Recommended Fermenting Accessories

Here are a few cool things that you might want to consider if you decide to start fermenting. I love my cabbage pounder and also have a shredder similar to the one below. I've used a knife for a long time, but the shredder speeds the process.

Himalayan salt is the best in my view, check out my article on the best type of salt for fermenting if you'd like to learn more.

1 thought on “How Long To Ferment Sauerkraut?”

  1. Ive been keeping homemade sauerkraut in my fridge in the garage. It freezes lettuce. I just ate some 2 year old sauerkraut. It tasted great, buy now Im afraid we will suffer with a terrible bug. Please help asap.


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