Making sauerkraut in a crock is the traditional way to prepare this probiotic vegetable ferment. While modern water locks make it easy to do small-batch sauerkraut in a mason jar, this old school method is still one of the easiest ways to make sauerkraut at home.
Basics of Homemade Sauerkraut
Homemade sauerkraut is incredibly easy, and all you really need is a bit of fresh cabbage, salt, and patience. There are many ways to make it, and all manner of modern appliances and tools designed to make a simple process even more foolproof.
Regardless of the tools used, the process of making sauerkraut is always the same.
- Chop Cabbage ~ Fine or coarse chop, doesn’t matter. Red cabbage, green cabbage or napa cabbage, it makes no difference.
- Place in a Container ~ Anything that holds water will work. A bowl, jar, or in this case, an earthenware crock.
- Add Salt ~ Generally about 2% by weight. Weight the cabbage, then multiply by 0.02. Some recipes use 1.5%, others use as much as 3%. Don’t have a scale, no worries. Exact amounts matter less than you think. More on this later.
- Pound the Cabbage and Salt Together ~ The salt, along with a bit of mechanical force helps the cabbage release its juices. I use a big wooden spoon, but they sell specialized sauerkraut pounders these days. Continue pounding until the cabbage is covered by its own juice, about 5-8 minutes.
- Weigh Down the Cabbage ~ Place some kind of weight on the cabbage to keep it submerged. Again, they sell fancy pickling weights for this, but a small saucer, jar, rock or even a Ziploc bag filled with water will work. Anything to hold the cabbage under the brine.
- Allow the Sauerkraut to Ferment ~ The total amount of time will depend on the temperature in your house and your own tastes. Recipes range from 3 to 6 weeks.
Once the sauerkraut has “finished,” it’s best to keep it in a cold environment to slow down the fermentation process. Raw sauerkraut will keep a long time, assuming it’s not contaminated and it’s kept under the brine.
Sauerkraut was traditionally made in an earthenware crock and kept in the root cellar or basement, where it would ferment during the last warm-ish days of fall after the harvest, and then keep all winter long. A sauerkraut crock is a natural preservation vessel, designed to both make and store the sauerkraut.
Choosing a Sauerkraut Crock
There are two main types of sauerkraut crock: Open Crocks and Water Sealed Crocks. In plain terms, one type is open with no meaningful seal or water lock, and the other has a rim that holds water and creates a one-way valve to seal the crock.
Each has its own advantages and disadvantages.
Open Sauerkraut Crocks
Open Crocks are just a glazed stoneware crock with straight sides and a lid that sits on top. While it’s not exactly “open” since it does have a ceramic lid, the lid doesn’t “seal” in any way, and more or less just keeps dust and critters out of the crock.
Inside the crock, the sauerkraut is weighed down by weight to keep it under the brine. This prevents mold from developing on the surface and keeps the cabbage in an anaerobic environment that’s necessary for sauerkraut fermentation.
I chose an open crock because I can use the crock for a number of other food preservation projects. Historically, they were used for egg preservation, preserving cheese in wood ash, potting meats or making duck confit.
As you can see, I get a lot of mileage out of my stoneware crock, and it’s not just for sauerkraut.
The downside is that without a seal, the sauerkraut is at a higher risk of developing kham yeasts (harmless, but ugly) on the surface, or surface mold if any sauerkraut floats above the brine (so keep it under the weight).
Water Sealed Sauerkraut Crocks
Many years ago in college, I used a water-sealed crock made by a potter roommate of mine. It was a huge hand made 5-gallon crock, elaborately painted and a true labor of love.
Back then, the only way to get a water-sealed sauerkraut crock was to commission one from a potter, since it was long before home fermentation came back into vogue.
These days, there are multiple brands of water sealed sauerkraut crock in all manner of sizes and colors. They used to be quite expensive as a specialty good, but now they’re about the same price as open crocks.
Water sealed crocks have a U-shaped well all along the top edge of the crock. Fill that well with about 1/2 inch of water and then put on the matching lid and you’ve created a water-lock or one-way valve.
Bubbles from inside the sauerkraut crock can push their way out, but outside air cannot get into your ferment.
A water lock is an extra bit of protection against contamination by mold, yeast, and fruit flies. Many people will only make sauerkraut with a water-sealed crock, but personally I don’t find it to be strictly necessary.
I love my versatile open crock, but if you’re only ever going to use your crock for sauerkraut, it makes sense to get a specialized water seal crock since they’re about the same amount of money.
How to Make Sauerkraut in a Crock
Regardless of the type of crock, the process of making sauerkraut is the same.
Start by shredding or chopping the cabbage. I generally slice the cabbage in half, take out the core and then slice it into long, thin strips. You can use a mandoline cabbage slicer or just a sharp chef’s knife.
That’s my preference, but there’s really no right way to do it.
Some eastern European methods dice it into 1 or 2” squares, which works well if you’re going to use it in sauerkraut soups later. Other methods toss whole cabbages into a giant crock, no chopping at all. (Though if you’re going to do cabbages whole, the process is a bit different because the brine needs to penetrate the whole cabbage.)
The reason I go with thin slices is because they’re versatile to use, easy to eat and the thin slices mean that the cabbage releases plenty of its own juices to create a flavorful brine.
Once the cabbage is sliced, add it to your fermentation crock. It takes about 3 lbs of sliced cabbage to fill my one-gallon crock to the top. Once muddled down and salted, the crock will only be about half full.
All in all, my one-gallon fermentation crock can hold about 5 to 6 pounds of cabbage for sauerkraut, provided that the only other ingredient is salt and no water is added. If I want a full crock, I’ll let my initial 3lb cabbage get started and then add more sliced cabbage and salt a few days later.
Add salt, and pound down the cabbage until it releases its juices and the salt is well incorporated. Use either a strong wooden spoon, your fist or a sauerkraut pounder.
How Much Salt To Add to Sauerkraut
So here comes the million-dollar question…how much salt to add to sauerkraut?
In a recipe with just two ingredients, the amount of salt is the only real measurement. Use a digital scale to weigh the cabbage, and then add in 2% of that weight in salt.
I started with a medium-sized 3 1/2 pound cabbage, and trimmed off the outer leaves and core, leaving 3 pounds of shredded cabbage. That’s about 1360 grams. Multiply that by 0.02 and you get roughly 27 grams, which worked out to be exactly 4 tsp of fine pink Himalayan salt.
Salt measurements vary pretty widely in sauerkraut, and there are even some techniques for making vegetable ferments without added salt (but you’ll need a culture to get those off to a good start, and honestly, no salt is pretty bland).
Some recipes use as little as 1%, but those are higher risk of spoilage. Others use 3% (or more), but they come out wicked salty. Starting with 2% salt by weight is a good middle ground, meaning a minimal risk of spoilage without being too salty.
If you don’t have a scale, really it’s not the end of the world. I imagine a babuska making sauerkraut in a crock a thousand years ago would have laughed at the thought of weighing the salt. Sauerkraut has enough salt when it naturally releases it’s juices, and those juices rise to cover the cabbage within 24 hours.
Add a bit of salt, pound the cabbage, then add a bit more. Once you’ve thoroughly pounded the salt into the cabbage, add the fermentation weights and give it some time.
With 3 lbs of cabbage and 4 tsp of salt, it took about 6 hours for the brine level to rise up to fully submerge both the cabbage and the fermentation weight. No need to add extra water and then the cabbage is fermenting in its own nutrient-rich juice.
An alternate method suggests adding 1 tablespoon of salt to a quart of water and then pouring it over the top of the cabbage. This makes measuring the salt easy, as you’re just adding a brine over the cabbage, and there’s no need to weigh anything.
Lacking a scale, use the brine method, or just use your best judgment.
Within a week, perhaps a bit sooner, you should see small bubbles rising to the top of the ferment. It’s not like making homemade wine, where the bubbles froth like crazy. They’ll only be a few, and it’s easy to miss.
If you don’t see your sauerkraut bubbling, no worries. I’ve had plenty of great batches where I never once saw bubbles, especially if it was particularly cold in the house.
Be sure to check in on the water level though, and it it starts to get low, add water. Some people say to add brine, but water is the only thing that has evaporated from the crock. All the salt you originally added is still in there. Adding more brine will only result in very salty sauerkraut.
I try to add water anytime the level drops below the top of the fermentation weights, and that ensures that everything says submerged.
Below you’ll see a photo of the sauerkraut crock after about 3 weeks of fermentation. There are visible bubbles, but the water level has dropped and I’m about to add more water to bring it up above the top of the weights.
My house stays pretty cool in the wintertime. Upstairs we usually keep it about 62, and our basement stays about 45 all year round. I’ll often allow my sauerkraut to go 6 or more weeks before sampling. Generally, if kept at room temperature (72 degrees) during the initial ferment, sauerkraut is finished to most people’s tastes in about 3ish weeks.
That said, when sauerkraut is finished is a matter of personal taste. It will continue to ferment with time, and the flavors will become more pronounced.
Generally, it’s started at room temperature for the first few weeks to ensure that it gets off to a good start and the lactobacillus outcompete any spoilage bacteria. After about 3-4 weeks, it’s moved somewhere cool for long term storage.
If sauerkraut is stored in a cool place, like the refrigerator or my 45-degree basement, it should keep on its own for 3-5 months. Be sure to keep the water line above the cabbage, and check periodically for spoilage.
Other than that, feel free to pull out a serving of kraut whenever the mood strikes you. Remove the weights, and use clean implements to scoop out as much as you need before replacing the weights and lid.
The process for fermenting in a crock, open or water sealed, is pretty straightforward.
I’ve taken you through the basics of making sauerkraut in a crock, but that’s not the only lacto-fermented vegetable you can make in a fermenting crock. Traditionally, all manner of vegetables would have been fermented this way, often adding brine for less juicy vegetables that cannot provide all their own liquid.
Feel free to experiment with other storage crops, like carrots or radishes, or add spices and turn your kraut into kimchi. If you want to get really adventurous, you can always try Russian Brined Apples for a unique treat.
More Easy Fermentation Recipes
Want to keep your crock bubbling? Try any of these easy fermentation recipes: