How to Make Easy Homemade Sauerkraut in a Mason Jar
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Sauerkraut is often one of the first fermentation projects recommended to curious DIY-ers, and with good reason: it's beyond easy to make, it requires very little special equipment, and the results are dependably delicious. All you need to do is combine shredded cabbage with some salt and pack it into a container — a crock if you have one and want to make a lot of sauerkraut, but a mason jar will do just fine for small batches. The cabbage releases liquid, creating its own brining solution. Submerged in this liquid for a period of several days or weeks, the cabbage slowly ferments into the crunchy, sour condiment we know and love as sauerkraut.
How is Sauerkraut Fermented?
Sauerkraut is made by a process called lacto-fermentation. To put it (fairly) simply: There is beneficial bacteria present on the surface of the cabbage and, in fact, all fruits and vegetables. Lactobacillus is one of those bacteria, which is the same bacteria found in yogurt and many other cultured products. When submerged in a brine, the bacteria begin to convert sugars in the cabbage into lactic acid; this is a natural preservative that inhibits the growth of harmful bacteria.
Why Should Sauerkraut Be Fermented?
Lacto-fermentation has been used for centuries to preserve seasonal vegetables beyond their standard shelf-life. The fermentation process itself is very reliable and safe, and the fermented sauerkraut can be kept at cellar temperature (around 55°F) for months, although those of us without cellars can make do with storing the kraut in our fridges. Besides preserving the cabbage, this fermentation process also transforms it into something incredibly tasty and gives it additional health benefits — fermented sauerkraut contains a lot of the same healthy probiotics as a bowl of yogurt.
What Do I Need to Make Sauerkraut?
At the most basic, all you need is cabbage, salt, and some sort of container to store it while it's fermenting. It's important that the cabbage remain submerged in its liquid during fermentation. When making sauerkraut in a crock, you usually place a weighted plate over the cabbage to pack it down and keep it submerged. When fermenting in a mason jar, inserting a smaller jelly jar filled with rocks or marbles in the mouth of the larger jar serves the same purpose.
The cabbage near the surface tends to float, so when fermenting in a mason jar, you need to either tamp down the cabbage a few times a day or place a large outer leaf of cabbage over the surface of the shredded cabbage to hold it down. Also be sure to keep the jar covered at all times with a clean cloth or piece of cheese cloth. This will allow airflow, but prevent dust or insects from getting into the sauerkraut.
How Long Does It Take To Make Sauerkraut?
For a small quart-sized batch like we're making today, the minimum time is about three days, though the kraut will continue to ferment and become tastier for many days after that. As simple as it sounds, the best rule of thumb is to keep tasting the kraut and refrigerate (or take it cellar temperature) when it tastes good to you. The sauerkraut is safe to eat at every stage of the process, so there is no real minimum or maximum fermentation time.
What Can Go Wrong?
Not much! You may see bubbles, foam, or white scum on the surface of the sauerkraut, but these are all signs of normal, healthy fermentation. The white scum can be skimmed off as you see it or before refrigerating the sauerkraut. If you get a very active fermentation or if your mason jar is very full, the brine can sometimes bubble up over the top of the jar. This is part of the reason why I recommend using a larger mason jar than is really necessary to hold the cabbage. If you do get a bubble-up, it's nothing to worry about. Just place a plate below the jar to catch the drips and make sure the cabbage continues to be covered by the brine.
It is possible that you might find mold growing on the surface of the sauerkraut, but don't panic! Mold typically forms only when the cabbage isn't fully submerged or if it's too hot in your kitchen. The sauerkraut is still fine (it's still preserved by the lactic acid) — you can scoop off the mold and proceed with fermentation. This said, it's still important to use your best judgement when fermenting. If something smells or tastes moldy or unappetizing, trust your senses and toss the batch.
Yields 1-1 1/2 quarts
1 medium head cabbage (2-2 1/2 pounds), cored and shredded
1 1/2 tablespoons kosher salt
air tight containers or mason jars
smaller jars as added weight
beans or marbles
Start by cleaning all of your utensils, including washing your hands thoroughly.
Wash your cabbage to rid it of any dirt or particles. Cut cabbage in half, then into quarters: core and slice into wedges.
Very thinly slice each wedge (across) into skinny strips; it should look like you’re making coleslaw.
In a large bowl, combine cabbage strips and salt. Use your hands to massage and break up cabbage, and combine it with the salt. Strips should begin to wilt after 5-10 minutes as their structure breaks down. Reserve the cabbage liquid.
Once cabbage is limp and watery, transfer to your fermenting containers, making sure container is big enough so there is extra space for the fermenting process. Pour excess liquids into storing container.
Pack down the sauerkraut so there are no air bubbles and it is submerged in its own liquid.
Cover cabbage with a smaller jar that’s been filled with beans or marbles for added weight. Again, this is to keep the cabbage submerged in brine.
Place cloth over the top of mason jar and secure with twine. The beginning of the fermentation process entails that the cabbage be left uncovered; the cloth prevents bacteria and particles from landing in the jars.
Leave uncapped mason jars at room temperature (our of direct sunlight) for at least 4 days, pressing down occasionally so cabbage stays covered by liquid.
After four days, begin tasting sauerkraut until it is to your liking. Then remove weighted jars, cap and refrigerate for up to 6 months. Enjoy!
Note: Bubbles and/or white bacteria developing on cabbage are a sign of healthy growth and can be removed without worry.