This is a tutorial for making basic sauerkraut. I’ve fielded a lot of questions from novice fermenters about how to make sauerkraut, so I hope this detailed photo tutorial will give others the confidence to try fermenting at home. This is intentionally a rather long post, as I’ve tried to be as thorough as I can. You may click on any of the photos to view them in a larger size.
First let’s discuss some of the basics of sauerkraut fermentation, so it doesn’t seem like so much of a mystery. Hundreds of years ago, people discovered that when they packed cabbages in a clay pot with salt, fermentation occurred, creating a tasty, tangy food that was well-preserved in an acidic brine. This new food was immediately recognized as being not only delicious and healthful, but a good way to preserve the harvest from season to season. The practice spread, until virtually all people who had access to salt used it to preserve vegetables in a similar manner. The simplicity of this preservation method coupled with its unique health benefits made it a popular food worldwide. Until the introduction of modern canning this was one of the chief methods people used to preserve their harvests. Recipes, traditions, and techniques that were passed from one generation to the next for two milllennia were nearly lost in just 150 years as people across the world embraced pasteurization, and later commercial food manufacturing. But the Internet has helped foster a new appreciation for old ways, and those of you who are missing the kinds of foods you ate as a kid can now make them for yourselves even if your grammy isn’t here to show you how.
So, what happens in sauerkraut and how do we know it’s safe? When shredded cabbage is mixed with salt at a ratio of roughly 2% (by weight), osmosis pulls the juice out of the vegetables, submerging them in a salty brine. Fresh vegetables, such as cabbage, are literally teeming with microbes both good and bad, but mostly good. Fortunately, it’s the good guys who love the salty brine – they quickly use up the available oxygen and the brine is then anaerobic, meaning it lacks oxygen. That lack of oxygen prevents the bad microbes that would spoil our food from taking hold. As the good bacteria multiply they create lactic acid, lowering the ph of the brine so that toxic organisms cannot reproduce. The lactic-acid bacteria thrive in this salty, acidic environment. They consume the starches in the cabbage, creating more lactic acid, carbon dioxide, and enzymes. Eventually they consume all the starches and their lifecycles are complete.
The final product is one that is tangy, fresh, and delicious, but also good for you in a number of ways. Firstly, the sauerkraut is extremely easy for you to digest, since the bacteria have essentially predigested it for you. All of the nutrients are readily available for your body to absorb with minimal digestive effort, and none of the unpleasant side effects one experiences when eating fresh or cooked cabbage. Second, the lactic acid helps to keep your stomach and bowels at the proper ph. Third, enzymes in the saurkraut help you digest your food without depleting your body’s own finite source. And last, the sauerkraut will be teeming with beneficial bacteria – you’ve probably heard them called probiotics – which improve digestion and your overall gastrointestinal health.
I hope I’ve given you enough reason to try making sauerkraut at home! Continue reading to learn just how easy it is. 🙂
1 Quart or Liter
1 head cabbage, green or red – approximately 2lbs.
1T salt (see below)
1 jar with lid, either quart or liter (wide-mouth is easier to work with)
Please note: I’ve used a mason jar for this batch, but you can use any lidded jar you have available, including an old pickle jar or a wire-bale European canning jar.
*Plain kraut is pretty awesome on its own, but dried spices are often used for flavoring. Try adding 1 teaspoon of your favorite whole spices such as: caraway seed, dill seed, celery seed, fennel seed, juniper berries, mustard seed, or peppercorns.
Rinse your cabbage and remove and discard any blemished leaves, especially ones with black spots. Then peel off one whole leaf and set it aside. Cut the cabbage down through the core into two halves, and then cut each half again into quarters. Remove the cores from the cabbage quarters.
Place one wedge of cabbage on your cutting board cut-side down, and slice across the grain as thinly as you can. Don’t worry if you can’t shred it super-thin, it will still make really good kraut.
As each quarter is shredded, put the cabbage in a large bowl and sprinkle with some of the salt. Keep adding cabbage and salt in layers until you’re out of both. You now have a big, fluffy mound and you’re probably thinking “No way is that going to fit in one jar.” But it will! I promise!! 😉
Now it’s time to get your hands dirty. (But wash them first!) Reach in the bowl with both hands and toss the cabbage well to incorporate the salt evenly. Then squeeze and massage the cabbage a bit to work it in. Next you want to pound the cabbage to begin breaking down the cell walls and releasing the juice. For this you can use: your fists, a sturdy glass or jar, or a pestle. Pound it down flat, then toss it all together and pound it again.
Keep pounding and mixing until the cabbage is wilted and juicy. I usually find that this takes about 5 minutes, or just a little longer. (When working with larger quantities, pounding the cabbage until it gets to this point is sometimes more work than I want to do. In that case, I pound for a few minutes, then put a plate on top and a heavy can on that. I then cover the bowl with a towel and let it sit for a couple hours so osmosis can do the work for me.)
If you want to add some spices, now is the time to do it. Sprinkle 1t on top and toss to mix. Then add a couple handfuls of cabbage to the jar and use your fist, a pestle, or anything you can fit in the jar to pack it down firmly. As you push the cabbage down the brine will rise up in the jar. Keep adding and packing down the cabbage until the jar is filled to about 2 to 3 inches from the top. DO NOT OVERFILL! Two pounds of cabbage fits perfectly into a 1 quart or liter jar. If you find that the jar is full but there are still a few spoonfuls of cabbage left, do not be tempted to add them to the jar. Sauerkraut is a very active ferment that bubbles vigorously and swells up in the early stages – if you add too much cabbage to the jar it’s going to ooze all over the counter and you’ll lose that tasty juice. 🙁
Now take the clean cabbage leaf you reserved and lay it flat on your cutting board. Set the jar on the leaf, near the top where it is more pliable. Use a sharp knife to cut a circle out of the leaf, exactly the diameter of the jar.
Place the cabbage circle on top of the shredded cabbage. It acts as a barrier to keep little bits of cabbage from floating to the top of the brine, where they could mold. Now you’ll need to put a little weight on top of the cabbage leaf to keep everything submerged. Some good options are: a small shot glass; a very small jar; clear glass marbles (like florists use); a clean, boiled rock; a small zip-top bag filled with a brine of ½t salt dissolved in ½c water; a small glass lid from a European-style canning jar, such as Weck or Fido. You don’t need to get fancy with this – just look around your home and use what you have available. The one exception is that you shouldn’t use metal, since sauerkraut is acidic and can be corrosive.
Now place the lid on the jar and screw on the metal ring. Tighten it all the way and then loosen it a half-turn. Fermenting cabbage makes a lot of gas in the early stages, and if the lid is too tight the pressure could build, causing the jar to break. (If you’re concerned about excess pressure you can also “burp” the jar occasionally in the first couple weeks by loosening the ring until you hear a “pffft” of gas escaping.) Write the date on the side of the jar with a marker and set the jar in a cool place to ferment. Cabbage is a cool-weather crop, and fermentation can proceed too quickly at temperatures above 75°, giving your kraut a “green” flavor and increasing the risk of spoilage. If you want to make sauerkraut in the summer (and I do) look around your house for some place that stays a little cooler, such as a closet or basement. You’ll also want to keep your kraut out of the light; if it’s fermenting on a counter, cover it with a towel.
Fermentation occurs under the brine, so it’s important to keep everything submerged. On the first day, your kraut may be a little dry on top. This is fine as the cabbage will continue to release more juice. Check it after a day or two: if there isn’t enough liquid then mix a brine of ½t salt in ½c water and add enough of that to cover the cabbage by about a half inch.
Within a day or two fermentation will begin. You will see bubbles appear and the cabbage will lose its bright green color. At this stage fermentation is very active – it bubbles all throughout, it may get a bit foamy on top, and it’s going to swell up almost to the top of the jar. This is why it’s so important to leave some space at the top for expansion. In the picture below you can see that the kraut now reaches the top of the jar after just a few days! At this stage it’s fun to check on your kraut regularly to see how it’s changing.
Vigorous bubbling will subside sometime between 2 and 4 weeks. This is because the bacteria grow in different stages: as the kraut becomes increasingly acidic, some bacteria die off and others take their place. The early stage bacteria are very gaseous; later stage bacteria are not. Many people mistakenly think cessation of bubbling means the kraut is finished – it is not! At this point if you sample it you’ll find it is pretty tangy, but the cabbage still tastes raw and crunchy, and there might be noticeable saltiness. Give your kraut more time! Right now it is more of a lightly fermented salad – good, but not well-preserved, and still far from being a traditional sauerkraut.
Since it is done producing gas, the kraut may have settled in the jar a bit. At this stage it will also reabsorb much of the liquid that it had released earlier. This is why you must not overfill your jars – if the liquid oozed out your kraut will no longer be submerged. If you do find that the cabbage is poking up out of the brine, open the jar and push down gently on the top until the brine rises up to cover the veggies. If you have insufficient brine in the jar, mix ½t salt in ½c water and pour enough of that on top to fully cover the kraut. You may now tighten the ring completely for the remainder of the fermentation, as there won’t be any more off-gassing.
Sauerkraut fermentation is a process that takes several weeks. How long will depend on a number of factors including: the sweetness of the cabbage, ambient temperature, salinity, whether you’ve got the Fermentation Fairies on your side. . . 😉 A good general rule is to check your sauerkraut at 4 weeks – if it is still bubbling give it another week; if not, have a taste. The strips of cabbage should no longer taste raw or have any sweetness left, they should be fermented all the way through and translucent. The saltiness will also be considerably diminished. If you find that fermentation is not complete, give it another week or two. I live in a temperate climate so my house is fairly cool year-round, and I’ve found that 6 weeks is the perfect amount of time to ferment sauerkraut here. Below is a photo of the kraut after 6 weeks of fermenting – fresh and tangy with some nice crunch to it. Delicious!
At this point you should move your sauerkraut to the fridge to slow fermentation. Kept in a cold fridge it will stay tangy and crisp for many months. If you have a cool basement or cellar, that’s also a good place to store it. But I predict it won’t last long! Sauerkraut is so good with almost everything – sandwiches, hot dogs, pizza, chili, pot roast, stew, salads, eggs. . . Pretty much the only food I don’t eat it with is dessert! (Although I’ve heard there’s a chocolate cake recipe that calls for sauerkraut, so you never know.) This jar is going fast, so I’d better get another one started right away. In fact, once you get the hang of making kraut you’ll probably want to start a new jar every 3-4 weeks. There are so many possibilities for flavoring kraut that you’ll never get tired of it. Experiment with different spices, or try adding thinly sliced onions, apples, turnips, or grated carrots or beets. The possibilities are endless! Or try one of my advanced recipes, such as Spicy Sauerkraut or Kraut-Chi. 🙂
Choose a pure, unrefined salt with no additives for your sauerkraut. Salt which has had anti-caking agents added to it might give your kraut an off flavor, or odd color. For best flavor and most nutritional benefit, purchase a salt that has some color to it – usually pink or gray. The color indicates that all the healthful trace minerals are intact. Popular choices are: Redmond Real Salt, Pink Himalayan, or Celtic Grey Sea Salt.
For best results, you’ll want to use an amount of salt that is equal to about 2% of the weight of the vegetables. If you have a food scale, this is easy to do. If not, follow this rule: For each 2 pounds of vegetables you’ll need about 1 tablespoon of fine grind (or table) salt. Weigh your cabbage at the grocery store or check your receipt if it’s sold by the pound. For each half-pound over that amount, add another teaspoon of salt. These are general guidelines and you don’t have to be too fussy about it, because anywhere from 1% to 3% salinity will give you a nice sauerkraut, so a little bit of fudging either way isn’t going to ruin things. Many people don’t measure their salt at all, and simply salt to taste. (This is, in fact, how it was done in the old days.) If you’d like to try that here is what I recommend: Start with a little less salt than you think you need. After you’ve mixed it in have a taste. The cabbage should be salty enough that you don’t want to eat a big bowl of it, but not so salty that you can’t stand to eat a little forkful. Add more salt if necessary, but remember that you can’t take it back out.
Yeasts & Mold
Although the brine is anaerobic, at the surface some oxygenation can occur and this is where spoilage organisms can sometimes take hold. Using a lid is the best way to prevent these problems, since they need oxygen to reproduce, and the rapid carbon dioxide production will quickly force oxygen out of the jar. However, even when using a lid you might find something icky growing on the surface. Most of the time what you find will be completely benign. Let’s discuss the two possibilities:
Kahm yeast is a colloquial name for an overgrowth of bacteria or yeast that can occur on the surface of fermenting fruits and vegetables. The technical name is pellicle, meaning a thin skin that has formed on the surface. It is white, and may be powdery or thready in appearance. Sometimes there will be bubbles of carbon dioxide trapped in it. Kahm yeast is really quite pretty! It may have an odor of fermenting beer or rising bread dough. Although it is undesirable, kahm yeast will not make you sick or harm you in any way. Since it needs oxygen to grow, I’ve found it is best to leave it undisturbed in a lidded jar – if you open the lid to skim it off you’re just introducing more oxygen, encouraging further growth. When the kraut is finished skim the pellicle off before transferring the jar to the fridge. Below is a picture of some kahm yeast that grew in a batch of beet kvass I made.
Mold can be any of a number of multi-celled fungi that grow on food. It may be white, gray/black, blue-green, or pink, and could be furry, slimy, or might form little flowers. Some people are allergic to molds. Some molds can produce mycotoxins which result in a long list of ailments for humans and animals. (The big mold baddie is aflatoxin, which spoils grains that have gotten damp.) What you are most likely to encounter when making sauerkraut is furry white mold, sometimes with gray or black spores at the top, or little blue-green flowers of mold floating on the top of the brine. It’s important to note that in a soft food, the mold will have invisible tendrils extending down below the surface. According to the United States Dept. of Agriculture, if you find mold growing in a soft food (such as kraut) the entire batch should be tossed. (Read more here.) I can tell you that the traditional practice was to scoop and discard any mold growing on the top and eat the rest. But then, they couldn’t afford to toss their entire harvest of hundreds of pounds of cabbage. You, on the other hand, can drive to the market and spend a few bucks on a fresh cabbage anytime. I’ll leave it to you to decide what’s best, with a gentle reminder not to be “penny wise, but pound foolish.” 😉
If you’ve spent some time looking at sauerkraut recipes on the Internet, you’ve probably encountered a few that suggest adding a starter culture such as: a dried bacterial culture, whey, brine from an already fermented batch of kraut, or vinegar. Please, do not try any of these things as you are more likely to encounter problems and be dissatisfied with your results. All fresh vegetables have ample bacteria on them for fermentation – they do not ever need a boost, a jump start, or speeding up. I know if you’ve never done this before it can seem like magic and you might be questioning whether the process will work – I felt that way, too! But I promise you that this will work without adding anything extra. Vegetable fermentation is actually very well understood, with numerous scientific studies, and even whole textbooks written about it and they have all reached pretty much the same conclusion: you need only vegetables and salt. Adding starter cultures will disrupt the natural process, shortening important bacterial stages or even bypassing them altogether. When that happens the kraut may become bitter and soft. The worst thing you could do would be to add whey – dairy cultures are quite different from the soil-based microbes that ferment vegetables and adding them is very much akin to introducing an invasive species that consumes resources and displaces the native organisms. Powdered starters are less likely to do this, but they are expensive and there’s just no reason for you to spend your money on that when people have been making fermented vegetables for more than 2,000 years without it. And if that doesn’t convince you, consider this: Every fall, tens of millions of people in Europe, Russia, and the Korean Peninsula ferment billions of pounds of cabbage into sauerkraut and kimchi, and they’re not using any starter cultures.
Green or red cabbages are your usual choices for making sauerkraut, but the number of other vegetables you can add is endless. All root vegetables (turnips, beets, rutabagas, kohlrabi, carrots) make wonderful additions to kraut, as do radishes, onions, celery, leafy greens (collards, kale, mustard, chard), and even some fruits, like apples or cranberries. Just remember to follow the basic recipe of ½ tablespoon salt for each pound of vegetables. Slice everything thin, or grate for large or woody vegetables. Although it’s fun to make sauerkraut all year round with green cabbages from the store, the best time of year for making kraut is in the fall. After summer is over, when the weather has turned cool, the cabbages will be very large and sweet and juicy. Shop your local farmer’s markets to find the big white cabbages grown just for making kraut. They are huge, dense, and with a sweetness like apples. They’re so juicy you’ll never need to add any brine. Fall is the time of year when it’s nice to have a large crock for fermenting. I always fill up my 3-gallon crock in October with kraut to give away as Christmas presents in Decenmber.
In the photos above and below you can see the difference between white cabbages and green cabbages. The white cabbage weighed in at over 12lbs! It was so dense that my 8″ chef knife got lost in it, and hacking it apart required some serious muscle. The green cabbage was about 2½lbs. and much more manageable, but less sweet and juicy. Experienced fermenters can never pass up a big, white cabbage at the market!
I hope I’ve answered all your questions here, but if not just leave them in the comments and I’ll be happy to help you out. Now go get started fermenting! 😀