Sauerkraut

Sauerkraut is lacto-fermented white cabbage. Eat it raw (unpasteurised, chilled) in salads, or warm with potatoes and pulses. 100 g has about 1.5 g salt.

Sauerkraut is fermented white cabbage – simple on the ingredients list, but made in very different ways. When you shop, the key question is whether it's raw-fermented and unpasteurised or a heated, shelf-stable product. That difference explains why "sauerkraut" in the supermarket isn't automatically the same thing.

What is sauerkraut?

Sauerkraut is made by lactic acid fermentation of finely shredded white cabbage with salt. Naturally occurring lactic acid bacteria feed on the sugars in the cabbage and produce lactic acid, among other things, which shapes the flavour, acidity and shelf life.

Botanically, white cabbage is Brassica oleracea var. capitata. Sauerkraut has a long tradition in central and eastern Europe and is one of the classic fermented vegetables. In central Europe, fresh white cabbage is mainly in season in autumn and winter, but thanks to fermentation sauerkraut is available all year round.

Important: not all sauerkraut contains live microorganisms. Raw-fermented sauerkraut from the chiller cabinet can still contain live cultures. Pasteurised sauerkraut in jars, tins or pouches, on the other hand, has been heated, which largely inactivates the microorganisms.

Nutrition per 100 g

Values can vary slightly depending on the recipe and drained weight. Typical average values for sauerkraut:

Nutrient	Amount per 100 g
Calories	19 kcal
Protein	0.9 g
Fat	0.1 g
Carbohydrate	1.8 g
Fibre	2.9 g
Vitamin C	15-20 mg
Vitamin K	13 µg
Sodium	600-900 mg

Note: the sodium content can vary a lot depending on how much salt is used. With factory-made sauerkraut in particular, it's worth checking the nutrition table.

Why sauerkraut is interesting

Sauerkraut provides fibre with a very low energy density. That makes it a typical side with lots of volume and few calories.
Fermentation changes the food both microbially and in flavour. Raw-fermented products can contain live lactic acid bacteria, as long as they haven't been heated afterwards. You'll find more in our guide to the microbiome and the overview of live-culture supplements.
Sauerkraut contains vitamin C and vitamin K, plus smaller amounts of other micronutrients from the white cabbage.
In nutrition research, fermented foods are often studied in connection with dietary variety and the microbiome. Which specific effects come from a single product, however, depends heavily on the amount, your overall diet and individual tolerance.
Compared with many other sides, sauerkraut is very low in carbs. That's why it often fits into approaches such as a low-carb diet.

How to spot good sauerkraut in the supermarket

If you want to buy sauerkraut for the fermentation, the product you choose matters. These points help you tell them apart:

Chiller cabinet, not the tinned aisle: raw-fermented sauerkraut is usually kept chilled. Unchilled products are often pasteurised.
Words like "raw", "raw-fermented" or "unpasteurised": these are a good sign, but not the only thing to check.
Short ingredients list: ideally just white cabbage and salt. Spices are fine, but acidity regulators, preservatives or added sugar aren't needed for classic sauerkraut.
No heat-treatment terms: wording such as "pasteurised", "preserved" or a very long best-before date without chilling points more to a heated product.
Cloudy brine isn't automatically bad: with raw-fermented products, the brine can be naturally cloudy. That's not a defect.

The most common misconception: "fermented" and "with live cultures" aren't the same. A product can have been fermented and then heated later. The sour flavour stays, but not necessarily a meaningful amount of live microorganisms.

How to use sauerkraut

You can use sauerkraut cold or warm. If you've bought a raw-fermented product and want to keep the live cultures, it's best to eat it uncooked or warm it only very gently.

Good everyday uses:

as a small side with potatoes, pulses or roast veg
in bowls with quinoa, chickpeas and herbs
on savoury bread or sandwiches
finely chopped in a salad with apple, caraway and a little olive oil
as part of warm pan dishes, if the live cultures matter less to you

A slow start is practical: especially if you don't usually eat many fermented foods, 1-2 tablespoons are enough at first. That applies particularly if you react sensitively to fermented foods or foods with plenty of fibre. Sauerkraut combines well with other ingredients that contain fibre, such as linseed or pulses – ideally in an amount you tolerate well.

Buying & storing sauerkraut

When buying, look for a pale to slightly yellowish colour, a fresh, sour smell and a clean, short ingredients list. Very soft, brownish or strongly sulphurous-smelling sauerkraut is often less appealing in taste and smell.

Storage:

Unopened, chilled: raw-fermented sauerkraut belongs in the fridge.
After opening: always take it out with clean cutlery and make sure the cabbage stays covered by brine as far as possible.
Shelf life: opened packs usually keep for a few days to a few weeks, depending on the product and hygiene.
Pasteurised sauerkraut: often keeps much longer unopened, but doesn't have the same properties as the raw product.

If you meal prep, sauerkraut works well as a cold component. Our guide to meal prep for beginners goes with it.

Possible side effects / take care if

Not everyone tolerates sauerkraut equally well in every amount.

High salt content: if you've been told to watch your sodium intake, keep an eye on portion size and the label.
Histamine: fermented foods can be a problem for sensitive people. More in the guide to histamine intolerance.
FODMAPs and a sensitive stomach: sauerkraut can cause wind or tummy discomfort in some people, especially in larger amounts. If you have IBS, an individual test phase can make sense; see the FODMAP diet.
Slow start: if you rarely eat fermented foods, a small amount to start with often makes more sense than a big portion. For sensitive people, psyllium husk can also be interesting as a separately dosed way to add fibre.

Recipes with sauerkraut

Here are a few matching ideas and recipe starting points:

You can add sauerkraut to a potato bowl, a lentil salad or a savoury breakfast slice of bread, for example. If you're looking for matching ideas, fermented recipes, high-fibre recipes and low-carb recipes are a good addition too.

FAQ

Is sauerkraut in a jar always pasteurised?

Not always, but often. What matters is chilling, the ingredients list and wording such as "raw-fermented" or "unpasteurised". Unchilled products with a very long shelf life have usually been heated.

Does pasteurised sauerkraut still have nutrients?

Yes. It still provides fibre and, depending on the product, meaningful amounts of certain vitamins and minerals. What's usually missing are live microorganisms, which are largely inactivated by heating.

Can I heat sauerkraut?

Yes. Flavour-wise, that works well. But if you chose a raw-fermented product for its live cultures, heating it strongly works against that.

How much sauerkraut makes sense?

That depends on how well you tolerate it. Small amounts such as 1-2 tablespoons as a side are often practical to start with. If it agrees with you, you can increase the amount.

The bottom line

Not all sauerkraut is the same: when you shop, it makes a big difference whether the product was raw-fermented and left unpasteurised, or heated afterwards. If you're looking specifically for a traditionally fermented product, check the chilling, the ingredients list and the label carefully – ideally they list only white cabbage and salt.