Sauerkraut

What to expect

Taste

Sour, and it is a specific kind of sour that vinegar does not reproduce — lactic acid is rounder, softer and slightly cheesy where acetic acid is sharp and volatile. Under it, cabbage is sweeter than raw cabbage because fermentation has converted some of its sugars and softened its sulphurous edge. Salt is present throughout and should not dominate; kraut that tastes primarily of salt has not fermented long enough. Carrot adds sweetness. Caraway is the classic partner and is assertive — aniseed and rye-bread notes — and a small amount goes a long way. Over weeks the sourness deepens and the sweetness recedes.

Aroma

Clean and sharply sour, and the word clean is the important one — a good ferment smells bright and appetising, and anything that smells rotten, cheesy in a bad way, or of solvent has gone wrong. The smell changes over the first week from cabbagey to distinctly sour, and that change is the most reliable progress indicator you have.

Texture

Crunching, and that is the mark of a good one. Commercial pasteurised sauerkraut is usually soft, because heat treatment for shelf stability destroys the texture along with the live cultures. Home-fermented kraut kept cold retains a real bite for months.

Sound

The jar makes noise, which is genuinely one of the pleasures of doing this. From day two or three you can hear it fizzing quietly, and lifting the weight releases a soft hiss. When the noise stops, the vigorous phase is over.

How the flavour moves

Sourness first and immediately. Then salt, then the cabbage's own sweetness underneath. Caraway is aromatic rather than tasted and comes through the nose. The finish is clean and sharp and short, which is why it works as a foil rather than as a dish — it resets the mouth and gets out of the way.

Serve it

Cold from the fridge, usually. It is also good at room temperature and is cooked in a great many dishes.

Goes with

Fat, and it is one of the great foils for it. Roast pork, sausages, duck, goose. Rye bread and butter. Cheese. It is in shchi and in bigos and in choucroute garnie, and it is on a hot dog. Where it fails is next to anything delicate, and next to wine, which fermented acidity flattens.

Cook's notes

Difficulty

Easy, and the only genuinely important thing is accuracy with the salt. Everything else is patience and keeping the cabbage under the brine.

Cost

Almost nothing. Two kilos of white cabbage is one of the cheapest things in a shop.

Equipment

A very large bowl, a two-litre jar or crock, a weight to hold the cabbage down, and digital scales. The scales are the one piece of equipment that matters.

When to make it

Autumn traditionally, when cabbage is cheapest and best. Any time in practice.

Best season

Cabbage is at its best and cheapest in late autumn and winter, which is exactly when this was traditionally made.

You know it is done when

Bubbles rising through the brine within two or three days. The cabbage goes from opaque white-green to pale and slightly translucent. The brine goes cloudy, which is correct and is the bacteria doing their work.

And it feels like

It should still crunch. Sauerkraut that has gone soft has usually been fermented too warm, or the salt was under 2 per cent.

Food safety

This is the section that matters and it is worth reading properly. Everything must stay under the brine — submerged cabbage ferments anaerobically and the lactic acid that develops preserves it, while anything standing above the liquid is exposed to air and grows mould. A flat white film on the surface is kahm yeast: harmless, and skimmed off with a clean spoon. Fuzzy growth in blue, green, black or pink is mould, its threads run further into the jar than you can see, and the batch goes in the bin — it is not worth saving. Never seal the jar tightly; fermentation produces carbon dioxide and a sealed jar builds pressure. Use clean hands and clean utensils throughout. Properly made, the finished kraut is acidic enough to be genuinely safe, which is why this has been a preservation method for two thousand years.

Where it goes wrong

Guessing the salt, which is the fault — below about 1.5 per cent spoilage organisms outrun the lactic bacteria, and above about 3 per cent the ferment stalls and you have salty raw cabbage. Adding water at the squeezing stage, which dilutes the brine. Not squeezing hard enough or long enough, so there is never enough liquid. Letting cabbage stand above the brine. Sealing the jar. And throwing out a batch over kahm yeast, which is harmless.

If it does go wrong

Not enough brine after half an hour: press again, and only then top up with 2 per cent brine. White film: kahm yeast, skim it. Fuzzy coloured growth: mould, and the batch is finished. Soft and slimy: fermented too warm or under-salted. Not sour after a week: the room is cold — give it longer. Too sour: it is fine and it will only get more so; move it to the fridge, which slows it almost to a stop. Smells wrong rather than sour: trust that judgement and start again.

Making it ahead

It is nothing but ahead. A jar in the fridge keeps for months.

Keeping it

Once it tastes right, move it to the fridge with the brine and it keeps for months, slowly getting more sour. Always keep it submerged.

Reheating

It can be cooked — that is what shchi does with it — and cooking kills the live cultures. Eaten raw it is a live food.

Freezing

It freezes and the texture suffers. There is no reason to; it keeps for months.

Leftovers

The brine is the useful leftover. It is a live culture and a spoonful will kick-start the next batch, and it is drunk on its own in some traditions.

Scaling it

Freely, on the 2 per cent rule. Larger batches ferment slightly more slowly and are easier to keep submerged.

Substitutions

Any firm cabbage works — white, green, or the pointed varieties. Red cabbage ferments perfectly well and turns a spectacular magenta, since its anthocyanins react to the acid the same way pickled onions do. Juniper berries, dill seed and garlic are all traditional additions somewhere.

Dietary swaps

Vegan, vegetarian, dairy-free, gluten-free and nut-free, with nothing to adapt.

Shopping for it

Firm, heavy, tightly packed white cabbage. Salt without anti-caking agents. A jar or crock large enough that the cabbage does not reach the rim, since it needs room for the weight and the brine.

Keeping the cost down

Two kilos of cabbage costs very little and makes twenty servings, which puts homemade sauerkraut at a small fraction of the jarred price and makes it considerably better. Save a little brine to start the next batch.

Sustainability

Excellent. A cheap seasonal vegetable turned into something that keeps for months without refrigeration, energy or packaging. It is the shape of eating that most of human history had.

Nutrition

About 20 calories a serving. Unpasteurised sauerkraut is a live fermented food carrying lactic acid bacteria, and it retains the cabbage's vitamin C — a serving provides a meaningful fraction of a day's requirement, which is the whole reason it kept sailors alive. It is also high in sodium by nature.

Worth it?

Worth it, and it is the most interesting thirty minutes in this collection. It costs about two pounds, requires no equipment but scales and a jar, and produces something better than anything you can buy — because almost all commercial sauerkraut is pasteurised and this is not. Weigh the salt, keep it under the brine, and taste it from day seven.

Where it comes from

Origin

Central and eastern Europe for the tradition; the technique is far older and far more widespread than any single origin.

Also called

Sauerkraut in German, choucroute in French, kapusta kiszona in Polish, kvashenaya kapusta in Russian.

Said out loud

ZOW-er-krowt in German.

What the name means

Sour cabbage, literally. The French choucroute is a Frenchification of the Alsatian dialect word for the same thing.

History

Fermenting cabbage is ancient and pan-Eurasian. Roman agricultural writers describe preserving cabbage, and the practice is documented right across central and eastern Europe. The often-repeated story that it originated with labourers building the Great Wall of China, fermenting cabbage in rice wine, is repeated in a great many popular accounts and is not supported by evidence — Chinese fermented vegetables are genuinely ancient, and the specific chain of transmission to Europe is not documented. What is well documented is the science and one very famous application. The fermentation is a succession: salt at around 2 per cent creates conditions that favour lactic acid bacteria over spoilage organisms, and three species take over in turn as the acidity rises, each more acid-tolerant than the last. The result is preserved cabbage that retains its vitamin C, which is why Captain James Cook carried barrels of it on his Pacific voyages from 1768 and lost remarkably few men to scurvy — one of the clearest early demonstrations that diet prevented the disease, decades before anyone understood why.

Why it matters

It is the food of the European winter, and its cultural weight in Germany, Poland, Russia and Alsace is enormous. It also carries one of the odder pieces of linguistic history: during the First World War, American anti-German feeling led to sauerkraut being renamed liberty cabbage, which is a genuine historical episode and an instructive one.

When it is eaten

Winter, and constantly. It is a staple rather than an occasion food.

The traditional way

Salting, pounding and weighting in a stoneware crock, often a very large one, made once a year at the autumn cabbage harvest for the whole winter. The scale was communal — a household ferment of thirty or forty kilos was normal.

How it changed

Industrial sauerkraut is pasteurised for shelf stability, which kills the live cultures and softens the texture, and it is what most people have tasted. Refrigerated unpasteurised kraut has become widely available again in the last twenty years alongside a general revival of fermentation.

Regional variations

Alsace and Germany use caraway and juniper. Poland ferments whole heads as well as shredded and uses it in bigos. Russia adds carrot and sometimes cranberries or apple. Korea's kimchi is the same principle applied with chilli, garlic and fish sauce and is a whole cuisine of its own.

How this version differs

It includes carrot, which is the Russian and eastern European habit rather than the German one. It is unusually explicit about weighing the salt, which is the one thing that reliably decides whether a batch works.

Sources and credit

None. The Cook scurvy account and the liberty cabbage episode are matters of record.

Related recipes

Categories