What Is Sauerkraut? A Simple Guide to Fermented Cabbage
Sauerkraut is finely cut cabbage fermented with salt. During fermentation, naturally occurring lactic acid bacteria use sugars in the cabbage and produce acids, including lactic acid. This gives sauerkraut its sour flavour and helps preserve it. Traditional raw sauerkraut isn’t cooked or pasteurised after fermentation, so naturally occurring live cultures can remain in the finished food.
That’s the simple answer.
But if you’ve only ever seen sauerkraut in a jar beside the pickled onions, there are a few things worth understanding about what makes it different.
What does sauerkraut mean?
The word “sauerkraut” comes from German and translates simply as “sour cabbage”.
That’s a pretty accurate description of the traditional food.
But the cabbage doesn’t become sour because vinegar is poured over it.
Traditional sauerkraut gets its sourness through fermentation.
That distinction matters, particularly when you’re trying to work out what you’re buying.
What is sauerkraut made of?
At its simplest, sauerkraut needs just two ingredients:
cabbage
salt
That’s enough to begin lactic acid fermentation.
Many sauerkrauts include other vegetables, herbs and spices too. Beetroot, carrot, garlic, turmeric, ginger and chilli can all change the flavour and character of the finished ferment.
But cabbage remains the starting point.
You don’t need vinegar to make traditional sauerkraut, you don’t need to add acid.
And you don’t necessarily need to add a bacterial starter culture either.
The microorganisms involved in traditional spontaneous sauerkraut fermentation are already associated with the raw cabbage and its environment.
Research into sauerkraut fermentation has identified several groups of lactic acid bacteria involved as fermentation develops, including Leuconostoc, Pediococcus and different lactobacilli. The bacterial population changes over time rather than one single type of bacteria doing all the work. (PubMed Central (PMC))
Is sauerkraut fermented?
Yes. Traditional sauerkraut is fermented cabbage. More precisely, it undergoes lactic acid fermentation or lacto-fermentation.
When cabbage is mixed with the right amount of salt and kept under suitable conditions, microorganisms begin using sugars naturally present in the vegetables.
Lactic acid bacteria gradually become a major part of this microbial community.
As fermentation develops:
Sugars in the cabbage are used by microorganisms.
Organic acids are produced, including lactic acid.
The acidity increases and the pH falls.
The flavour changes from fresh cabbage towards the sour taste associated with sauerkraut.
The microbial community changes as fermentation progresses.
One 2022 study followed spontaneous sauerkraut fermentation for 42 days. The researchers recorded the pH falling from around 5.87 at the start to 3.36 by the end, while lactic acid increased during fermentation. (PubMed Central (PMC))
That’s fermentation happening in measurable terms.
For the person eating it, it’s also what creates the change in flavour, smell and texture.
How is sauerkraut made?
Traditional sauerkraut follows a surprisingly simple process.
1. The cabbage is cut
Fresh cabbage is shredded or finely sliced.
Cutting the cabbage creates a large surface area and helps release its natural juices.
2. Salt is added
Salt is mixed thoroughly through the cabbage.
The salt draws water out of the vegetables, helping create the brine in which the cabbage ferments.
Salt concentration also influences which microorganisms grow during fermentation.
Research into sauerkraut has identified both salt concentration and temperature as factors that shape its microbial community. (PubMed Central (PMC))
3. The cabbage is kept in its brine
The vegetables are packed down so the cabbage sits beneath the liquid.
This creates the conditions needed for the fermentation to develop.
4. Fermentation begins
The microorganisms associated with the cabbage start using its sugars. Different bacteria can become more or less common at different stages.
In one detailed study of organic artisanal sauerkraut, bacterial diversity changed during fermentation and lactic acid bacteria became dominant. The researchers found Lactiplantibacillus was particularly prominent in the finished sauerkraut they studied. (PubMed Central (PMC))
5. The flavour becomes increasingly sour
As organic acids build up, the cabbage changes. Fresh cabbage flavour gives way to something tangier and more complex. The finished result is recognisably sauerkraut.
Why does sauerkraut taste sour?
Sauerkraut tastes sour mainly because microorganisms produce organic acids as they ferment the sugars in cabbage.
Lactic acid is particularly important.
This means traditionally fermented sauerkraut doesn’t need vinegar to create its acidity.
The sourness develops naturally as part of fermentation.
A 2022 study looking at the biochemical changes taking place during sauerkraut fermentation recorded increasing levels of lactic acid as fermentation progressed, alongside changes in other microbial metabolites. (PubMed Central (PMC))
This is one reason naturally fermented sauerkraut tastes different from simply putting cabbage into vinegar.
Fermentation changes the food over time.
What does sauerkraut taste like?
Sauerkraut is sour, savoury and usually still has some crunch, but there’s no single sauerkraut flavour. Our approach at Wild Pantry is to make it delicious for everyone and not too sharp.
The cabbage, other vegetables, herbs, spices, salt level and fermentation all influence the finished food.
A plain white cabbage sauerkraut can taste very different from one containing beetroot, garlic and turmeric.
And fermented sourness isn’t quite the same as vinegar acidity.
When we make sauerkraut at Wild Pantry, the flavour develops as the vegetables ferment.
You’re tasting the vegetables themselves, but you’re also tasting what fermentation has done to them.
If you’ve tried one sauerkraut and didn’t enjoy it, that doesn’t necessarily mean you won’t like another.
Our separate guide to what sauerkraut tastes like explores this in more detail.
Is sauerkraut the same as pickled cabbage?
No,. the words “fermented” and “pickled” are sometimes used as though they mean exactly the same thing, but they can describe different processes.
Traditional sauerkraut develops its acidity through fermentation.
Many pickled vegetables get their acidity from vinegar or another acid added directly to the food.
So cabbage submerged in vinegar isn’t automatically sauerkraut in the traditional fermented sense.
Some products can contain both fermented vegetables and added vinegar, which is why checking the ingredients and production method tells you more than relying on the name.
Does sauerkraut contain vinegar?
Traditional sauerkraut doesn’t need vinegar. Its acidity is created during lactic acid fermentation.
Some commercial sauerkraut products may contain vinegar, so check the ingredients if this matters to you.
Finding vinegar doesn’t prove that the cabbage wasn’t fermented first. A producer can ferment vegetables and add vinegar afterwards.
If you’re looking for traditional naturally fermented sauerkraut, look for clear information about how it was made.
What is raw sauerkraut?
Raw sauerkraut usually means sauerkraut that hasn’t been heat treated after fermentation.
This matters because traditional fermentation can leave viable microorganisms in the finished food.
Research analysing artisanal sauerkraut has measured substantial populations of viable lactic acid bacteria towards the end of fermentation. (PubMed Central (PMC))
A raw sauerkraut is normally refrigerated to slow ongoing microbial activity.
But “raw” can be used differently by different producers.
If live cultures are part of the reason you’re choosing a particular jar, look for more precise wording such as:
naturally fermented
raw
unpasteurised
contains live cultures
keep refrigerated
What is unpasteurised sauerkraut?
Unpasteurised sauerkraut has not been pasteurised after fermentation.
Pasteurisation is a heat treatment. The Food Standards Agency describes it as using a combination of time and temperature to inactivate microbial flora to a required level. (Food Standards Agency)
This gives us an important distinction.
Both raw and pasteurised sauerkraut may have been fermented, the difference comes afterwards.
Raw, unpasteurised sauerkraut: Fermented, then kept without pasteurising it. Viable microorganisms associated with fermentation can remain.
Pasteurised sauerkraut: Fermented, then heat treated. This greatly reduces or inactivates viable microorganisms.
Pasteurisation doesn’t mean the food wasn’t fermented, and it doesn’t make pasteurised sauerkraut “fake” sauerkraut. They’re simply different finished products.
Is live sauerkraut the same as unpasteurised sauerkraut?
“Live sauerkraut” usually refers to fermented sauerkraut that hasn’t been pasteurised and still contains viable microorganisms associated with fermentation.
There’s a useful wording distinction here too.
You’ll often hear these microorganisms called “probiotics”.
We prefer to say “naturally occurring live cultures” when talking about sauerkraut generally.
The term probiotic has a more precise scientific meaning. A microorganism needs evidence showing a health benefit when consumed in an adequate amount before that label can properly be applied.
Sauerkraut can contain a varied population of microorganisms and this can differ between fermentations. (PubMed Central (PMC))
So “live cultures” tells you what you’re dealing with without making a bigger health claim.
Is sauerkraut good for gut health?
This question deserves more than a yes or no answer.
Sauerkraut is a fermented food and raw sauerkraut can contain naturally occurring live microorganisms. Scientists are studying how fermented foods interact with the human gut microbiome and wider health.
But research into sauerkraut specifically is still limited.
That means we shouldn’t jump from “contains live cultures” to claims that eating sauerkraut will fix your gut microbiome or treat digestive problems.
There is human research into sauerkraut, including trials comparing pasteurised and unpasteurised versions, but the evidence isn’t strong enough to support many of the sweeping claims made online.
If this is the reason you’ve become interested in sauerkraut, read our guide to whether sauerkraut is good for gut health or our closer look at the research into sauerkraut benefits.
How is Wild Pantry sauerkraut different from traditional plain sauerkraut?
We start with the same basic idea: vegetables, salt and natural fermentation.
Then we build flavour through a wider mix of vegetables, herbs and spices.
PowerKraut contains cabbage, beetroot, carrot, turmeric, garlic, red onion, Celtic salt and black pepper.
That creates a very different jar from plain white cabbage sauerkraut.
PowerKraut received a Great Taste Award in 2026.
We also make ImmuniKraut using organic vegetables including ginger, turmeric, fennel, turnip, carrot, garlic and black pepper.
Both are raw and unpasteurised.
We don’t see these extra ingredients as replacing traditional sauerkraut.
They’re our way of taking the basic fermentation process and creating flavours that work with the food we like to eat.
How do you eat sauerkraut?
You can eat sauerkraut straight from the jar or serve it alongside everyday meals. There’s no need to make a special “gut health” meal around it.
Try a forkful with:
eggs
avocado
sourdough
sandwiches
salads
baked potatoes
grain bowls
sausages
roasted vegetables
We often suggest starting with a small amount alongside food you already enjoy.
That’s how sauerkraut becomes an ingredient rather than another jar you bought because someone told you it was good for you.
If you want more ideas, read our guide to how to eat sauerkraut.
Does cooking sauerkraut matter?
Heating raw sauerkraut will affect the viable microorganisms in it.
So if you’ve specifically bought unpasteurised sauerkraut because you want its naturally occurring live cultures, eating at least some of it without cooking makes more sense.
That doesn’t mean sauerkraut suddenly becomes worthless if you heat it.
You can still enjoy the cabbage itself, its flavour and compounds created during fermentation.
Think about why you’re eating it.
If it’s mainly because you enjoy the flavour, use it however you like.
If keeping the cultures viable matters to you, add it after cooking or serve it cold alongside the meal.
How should raw sauerkraut be stored?
Follow the storage instructions on the jar.
Raw, unpasteurised sauerkraut is commonly kept refrigerated because colder temperatures slow the microorganisms responsible for fermentation.
A live ferment can remain active in the jar.
We see this first-hand when working with fermented vegetables. Brine can move, small bubbles can appear and pressure can sometimes build.
Fermentation also means there can be natural variation from one batch to another.
That’s part of working with a food created by microorganisms rather than simply adding an acid to vegetables.
How can you tell if sauerkraut is traditionally fermented?
Look beyond the word “sauerkraut” on the label.
If you’re looking for traditional raw sauerkraut, check:
Does it say naturally fermented?
Does it say raw or unpasteurised?
Does it mention live cultures?
Does it need refrigeration?
What ingredients are used?
Does it contain added vinegar?
Does the producer explain how it is made?
No single clue tells you everything.
For example, refrigeration doesn’t automatically prove that something is unpasteurised.
And vinegar on the ingredients doesn’t prove it was never fermented.
A good producer should be able to explain what has happened between fresh cabbage and the jar you’re holding.
Frequently asked questions
What is sauerkraut in simple terms?
Sauerkraut is cabbage fermented with salt. Naturally occurring microorganisms use sugars in the cabbage and produce acids, including lactic acid. This gives sauerkraut its sour flavour and helps preserve it. Other vegetables, herbs and spices can also be included.
Is sauerkraut just fermented cabbage?
Traditional sauerkraut is fermented cabbage, but many versions contain other vegetables and seasonings too. Cabbage remains the main ingredient. The important part is that the characteristic acidity comes from fermentation rather than simply pouring vinegar over fresh cabbage.
What does sauerkraut mean in English?
Sauerkraut comes from German and means “sour cabbage”. The name describes the food quite literally: cabbage develops a distinctive sour flavour during fermentation.
Does sauerkraut have vinegar in it?
Traditional sauerkraut doesn’t need vinegar. Lactic acid and other acids are produced naturally during fermentation, giving the cabbage its sour flavour. Some commercial products may contain added vinegar, so check the ingredients if you’re looking for traditionally fermented sauerkraut.
Does sauerkraut contain live cultures?
Raw, unpasteurised sauerkraut can contain naturally occurring live microorganisms associated with fermentation. Research has found viable lactic acid bacteria in artisanal sauerkraut. Pasteurisation uses heat and greatly reduces or inactivates these microorganisms. (PubMed Central (PMC))
Is all sauerkraut unpasteurised?
No. Some sauerkraut is sold raw and unpasteurised, while other sauerkraut is pasteurised after fermentation. Both can still have been genuinely fermented. Check the label if you’re specifically looking for sauerkraut with naturally occurring live cultures.
Why doesn’t sauerkraut go off like ordinary cabbage?
Fermentation changes the environment around the cabbage. Lactic acid bacteria produce acids, the pH falls and the increasingly acidic conditions help preserve the vegetables. Salt also plays a part in shaping the fermentation process. This is one reason fermentation has long been used to preserve vegetables. (PubMed Central (PMC))
Is sauerkraut a probiotic food?
It’s more accurate to say that raw, unpasteurised sauerkraut can contain naturally occurring live cultures. “Probiotic” refers to microorganisms with a demonstrated health benefit when consumed in adequate amounts. The microorganisms present in naturally fermented sauerkraut can vary, so the terms shouldn’t automatically be treated as interchangeable.
Research and sources
How Microbiome Composition Correlates with Biochemical Changes during Sauerkraut Fermentation: a Focus on Neglected Bacterial Players and FunctionalitiesMicrobiology Spectrum, 2022This study followed spontaneous sauerkraut fermentation for 42 days, tracking bacterial succession, acidity, pH and metabolites. (ASM Journals)
Microbial and metabolic characterization of organic artisanal sauerkraut fermentation and study of gut health-promoting properties of sauerkraut brineFood Research International, 2022The researchers studied organic sauerkraut from two producers and found lactic acid bacteria became dominant as fermentation progressed. The study included laboratory work relating to potential gut effects, rather than a human clinical trial, so those findings shouldn’t be treated as proof of a health benefit in people. (PubMed Central (PMC))
Fermented Foods: Definitions and Characteristics, Impact on the Gut Microbiota and Effects on Gastrointestinal Health and DiseaseNutrients, 2019A review covering the characteristics of fermented foods, including sauerkraut, and the evidence around their relationship with gastrointestinal health. (PubMed Central (PMC))
Food Standards Agency: PasteurisationUK Food Standards AgencyDefines pasteurisation as heat treatment using a combination of time and temperature to inactivate microbial flora to a required level. (Food Standards Agency)
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