Fermenting Sauerkraut at Home

One of the world’s quintessential beer foods, sauerkraut is a delicious treat at any time of the year. Sauerkraut is also the perfect food for this world-historical moment when many of us are stuck at home and digging in for the long haul. Loaded as it is with folate, Vitamins B6, C, and K, riboflavin, thiamin, iron, potassium, and magnesium, sauerkraut is a “superfood” — which is super news at a time when we want to keep our immune systems running at peak efficiency.

In this two-part series, I’ll give you the goods on fermenting sauerkraut at home, and then provide you with a few recipes to get you on your way. [Edit: This never did become a two-part series, but if you scroll down and check out Related Posts, you’ll find a few recipes that’ll make your home-fermented sauerkraut shine.]

So forget the canned sauerkraut. Just think of how your home-fermented sauerkraut will taste with a soft Helles, a crisp Pils, a spicy Saison, a sour and funky Gueuze, or a smoky Rauchbier. Sublime, I’d say.

Sauerkraut through the ages

Sauerkraut needs no introduction. It plays a supporting role in North American comfort foods from hot dogs to Reubens, adding a nice tang that cuts through the fat of the main attraction. In Central Europe, sauerkraut is an important accompaniment to rich pork and sausage dishes, and can even be a meal in its own right. Nothing beats a platter of sauerkraut, potatoes, smoked ham, and sausages during the cooler months, especially when there’s beer or wine at hand.

Sauerkraut may well be a German staple, but the French have their choucroute, and the Dutch their zuurkool. Variations on sauerkraut are just as prominent in lands further east and southeast. Poland, the Baltic States, the Czech Republic, Slovakia, Ukraine, Hungary, Romania, countries in the Balkans, Russia: all of them chop up cabbage, ferment it, and use it in main courses, salads, and soups. And that’s just Europe.

Although English speakers borrowed the word from German, sauerkraut did not originate in Germany. That honour falls to the Chinese, who were already fermenting cabbage in rice wine over 2,000 years ago. Sauerkraut eventually found its way to Europe, introduced either by Genghis Khan during his incursions, or by nomadic Tatars. Whatever the case, Jewish communities in Eastern Europe adopted sauerkraut and are thought to have introduced it to Europe more widely. Europeans dispensed, in large part, with the wine and began curing their shredded cabbage with salt round about the sixteenth century.

Fun fact: Though you’ll still find plenty of sauerkraut in Germany, per capita consumption of sauerkraut has dwindled to approximately 2.6 pounds, down from 4.4 pounds forty years ago. Even the French eat more sauerkraut: 3.75 pounds of sauerkraut per person. But those numbers pale in comparison with the 49 pounds of kimchi that the average Korean consumes per year. (Source: GermanFoods, “Sauerkraut: Germany’s Superfood.”)

Fermenting Sauerkraut at Home

A perennial November scene. The last leaves have fallen from the trees and the air portends snow. Ripe and rotund cabbages dot the fields of Central Europe, ready for harvest. Families across the region fan out into their plots with sharp cutting implements and load their carts with head after head of cabbage. Back at the farmhouse they set to the task of shredding these green globes into mountains of filaments destined for the sauerkraut barrel. Sauerkraut was an indispensable staple for these families during winter months, for fresh vegetables were virtually nonexistent. As many as 300 heads of cabbage went into the wooden barrels, especially if the brood was large. Some families spiced their cabbage with caraway seeds, others added other vegetables to the barrel to keep the cabbage company. In went the salt, too, yielding the brine that would turn the cabbage tangy, fortified occasionally with wine.

Today, all you need is a head of cabbage, salt, a sharp knife, a scale, a suitable container, something to weigh down the shredded cabbage while it ferments, and time. If you start now, your sauerkraut will be ready in three to six weeks.

*You can use a crock for larger amounts, or food-grade plastic containers for smaller amounts. If you’re using a crock, find a plate that fits into the opening of the crock and weigh it down with a jug of water. Water-sealed crocks, which often come with a set of handy weights, are also a good option, but they can get pricey. Here at home, we use a 4-liter plastic container and weigh the cabbage down with another container of the same size filled with water.  

1. Shred and weigh the cabbage

Using a sharp knife, cut your cabbage into quarters and core. Shred the cabbage finely with that same sharp knife, or, if you prefer, a mandolin or the shredding blade of your food processor. Set your scale to metric, then weigh the shredded cabbage and any accumulated juices.

2. Brine

To make your brine you need salt. But not just any salt. Stay away from standard iodized table salt, which contributes a metallic bite to your sauerkraut. The anti-caking agents also cast a sediment. Sea salt is your best bet, but you can also use pickling salt.

The brine creates an ideal environment for fermentation to take place. Notes Sandor Ellix Katz, “Brine serves as a protection against the growth of putrefying microorganisms and favors the growth of the desired strains of bacteria, Lactobacilli.”

You want to aim for a salt quantity that’s 2–3% of the weight of your shredded cabbage. (Traditional amounts are in the 1–2% range, which is below the USDA recommended minimum. If you use this low an amount, it’s imperative to ferment on the cool side.) The more salt, the slower the fermentation and the more acidic your sauerkraut. Use too much salt, though, and you’ll inhibit fermentation. The lower end of the salt range produces a sauerkraut with more crunch. But too little salt will speed up fermentation, which could leave you with soft, slimy fermented cabbage if your fermentation temperature is too high.

*A good rule of thumb: taste the brine as the cabbage is releasing its juices. If it tastes briny but not overly salty, you’re good to go. For what it’s worth, I find anything above 2.5% to be too salty.

So how do you get that briny elixir? After you’ve weighed your shredded cabbage in grams, calculate how much salt you’d need for your cabbage. Since you’re using metric, this calculation couldn’t be easier. Say you end up with 1000 grams of cabbage and want a brine that’s less salty. Simply multiply by 0.02, et voilà: 20 grams of salt. If you’re metric-averse, use 3 tablespoons of salt for every 5 pounds of cabbage.

If you’re working with a small amount of cabbage (one or two heads), sprinkle the salt over the shredded cabbage while gently mixing with clean hands. (We should all be familiar with that drill by now: 20 seconds, and scrub under your nails.) Once you’ve distributed the salt evenly, start massaging the cabbage so that it releases its juices.

3. Fermentation

Wash your fermentation vessels in hot, soapy water. If you’re a homebrewer and have some sanitizer kicking around, give everything a quick spray for good measure. Transfer cabbage and juices to your squeaky-clean fermentation vessel and tamp down to release any air bubbles. Feel free to toss in some spices at this stage. Caraway seeds, coriander seeds, or juniper berries are all fine candidates. Assuming your cabbage is relatively fresh, your sauerkraut-in-waiting should now be about an inch beneath the brine.

*If your cabbage is old, it’ll be a bit dry. Just make a quick brine and add it. One liter of water weighs one kilogram. Add 20 grams of salt, stir, and there’s your brine. Keep some in the fridge in case you need to top up your fermentation vessel later.

Next, weigh down your shredded cabbage with any non-reactive implement that fits snugly in your fermentation vessel. This will create an airlock. Cover with a pillow case to keep the critters out, place it in a cool spot — preferably one where the temperature is constant — and let the microbes work their magic. Check your sauerkraut periodically and skim off any mold blooms that form, and top up with brine if the sauerkraut starts to pop up above the surface.

How long should you ferment your sauerkraut?

How long do you have to wait? The short answer: until you like the taste and texture of your sauerkraut. You can dive right in after about ten days, but most experts recommend waiting three weeks to give all those beneficial microbes a chance to flourish. Writes Holly Howe, the self-proclaimed Sauerkraut Wizard, “This time span ensures good flavor development, proper acidity level and complete consumption of all the sugars in the cabbage.”

For the following guidelines, I’ve combined advice and suggestions from the National Center for Home Food Preservation (based on USDA recommendations), Harold McGee (On Food and Cooking), and the Sauerkraut Wizard:

• The optimal range is 64–76ºF (18–24ºC).
• At 60º–65ºF (16ºC–18ºC), fermentation can take five to six weeks. 65ºF (18ºC) is the sweet spot for colour, flavour, and Vitamin C levels.
• For perfectly good sauerkraut, ferment at 70º–76ºF (21ºC–24ºC). Your sauerkraut will be ready in three to four weeks.
• At 60°F (16°C), curing could take as long as six to eight weeks. Your sauerkraut may not ferment at temperatures below 60ºF (16ºC). Anecdotally, I’ve fermented sauerkraut at slightly lower temperatures. They just take longer to ferment.
• Elevated temperatures will have an adverse effect on the taste and texture of your sauerkraut. High temperatures may even be downright dangerous, especially if you’re using low amounts of salt. According to KitchenProject.com, temperature control becomes critical when using traditional amounts of salt (lower than a 2% ratio of salt to cabbage): “Food poisoning can occur if the fermentation temperature is too high.”

Holly Howe has this to say about fermenting at elevated temperatures: “Most of the work will be done by homofermentative bacteria, which produce lactic acid but not acetic acid and other flavors which contribute to the complex flavor of really good sauerkraut.”

So there you have it. Think of sauerkraut the same way you think of lager. Take your time, and ferment low and slow if you can.

When all is said and done

Sometimes good things don’t come to those who wait. As is the case with wild/mixed fermentation beers, a sauerkraut fermentation can occasionally go off the rails. If your sauerkraut smells moldy, don’t eat it. I’ve only had this happen once, and it was because I hadn’t sanitized the bricks that I was using to weigh down the plate in my crock. The bricks got moldy, and the mold penetrated the brine and the sauerkraut. Alas. You can also end up with subpar sauerkraut if you add too much salt, which inhibits the formation of Lactobacilli (see above). Trust me: No amount of food grade lactic acid will save a sauerkraut like this. Dump it in the compost and get back on the horse with your next fermentation. All you’ll have lost is a couple bucks.

Those are rare cases. More likely than not, your patience will be rewarded with a delectably sour and slightly crunchy sauerkraut that you can eat as is, or use as the base for simple yet sublime feasts. If it’s a bit salty, just give it a quick rinse and you’re off to the races.

Check out the recipes under Related Posts below for sauerkraut recipes that pair well with beer styles ranging from Helles to Rauchbier to Gueuze.

Sources

GermanFoods, “Sauerkraut: Germany’s Superfood.”

Sandor Ellix Katz, Wild Fermentation: The Flavor, Nutrition, and Craft of Live-Culture Foods (Vermont: Chelsea Green Publishing Company, 2003).

KitchenProject.com, “The History of Sauerkraut.”

Holly Howe, “How Long to Ferment Sauerkraut?” MakeSauerkraut.

Harold McGee, On Food and Cooking: The Science and Lore of the Kitchen, revised edition (New York: Scribner, 2004).

National Center for Home Food Preservation, “Preparing and Canning Fermented Goods.”

Barbara Rolek, “Sauerkraut: The Quintessential Eastern European Vegetable,” The Spruce Eats, October 2019.

USDA, “Safely Fermenting Food at Home,” 2015.

With the exception of the cover photo, all images by Franz D. Hofer. The “Sauerkraut” photo is from Tom Koch, Ghostletters Vienna: Traces of Urban Identity (Vienna: Falter Verlag, 2016). Click on this link to find a copy: https://shop.falter.at/ghostletters-vienna-17.html

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