Basic Sauerkraut

Keep the cabbage fully submerged under its brine at all times - exposure to air allows mould to grow. Use the salt ratio given; too little salt allows harmful bacteria to compete with the beneficial ones that make fermentation safe.

01Ingredients

1000g cabbage, finely shredded
20g non-iodised salt (2% of cabbage weight)
1 tsp caraway seeds (optional)

02Method

Massage salt into shredded cabbage in a large bowl for 5-10 minutes, until it releases enough liquid to submerge itself.
Pack the cabbage tightly into a clean jar, pressing down firmly so the liquid rises above the cabbage.
Weigh the cabbage down with a fermentation weight or a smaller jar filled with water, keeping it fully submerged.
Cover loosely and leave at room temperature for 1-4 weeks, tasting after the first week and continuing until it reaches the tanginess you like.
Once fermented to taste, seal and refrigerate to slow further fermentation.

03Notes & substitutions

Green or red cabbage both work well - red cabbage gives a striking colour.
Add grated carrot or sliced apple for a milder, slightly sweeter variation.
No fermentation weight? A well-washed rock in a small snap-lock bag works fine.
Vegetarian and vegan as written.

04Common mistakes

Not enough brine — if massaging doesn't release enough liquid to submerge the cabbage, top up with a 2% salt brine (20g salt per litre of water) rather than leaving it exposed.
Cabbage floating above the brine — the weight needs to hold everything under the liquid line, or exposed cabbage will mould.
Using iodised salt — it can interfere with fermentation; use plain, non-iodised salt instead.

05Storage & leftovers

Fridge

In its brine, keeps for several months once fermented to taste.

Freezer

Not recommended - freezing kills the beneficial live cultures fermentation creates.

Fermenting

See our Fermenting guide for the full, process and troubleshooting.

More About This Recipe

06Ingredient notes

Cabbage. Fresher, tighter heads ferment more reliably than older cabbage that's started to dry out at the edges.

Salt. The 2% ratio (by weight of cabbage) is the important number here - it's enough to favour beneficial bacteria without overwhelming the fermentation.

Caraway seeds. Traditional and optional - change the flavour direction without affecting the fermentation itself.

07Troubleshooting

White film on the surface. Usually harmless kahm yeast, not dangerous mould - skim it off and check the kraut underneath still smells and tastes right.
Fuzzy mould in colour (black, green, pink). A sign of contamination, usually from exposed cabbage above the brine - discard the batch rather than trying to salvage it.
Not enough liquid released. Keep massaging, or let it sit covered for 30 minutes and massage again - if it still won't release enough, top up with a 2% salt brine.
Tastes too salty or not sour enough. Ferment longer for more tang, or rinse briefly before eating if it tastes too salty for your preference.

Frequently Asked Questions

How do I know if my sauerkraut has gone bad versus just fermenting normally?

Normal fermentation smells tangy and sour, pleasant. A bad batch smells rotten or off, not just sour - if it smells wrong, discard it. Surface mould on submerged, properly salted kraut is rare; a thin white film (kahm yeast) is harmless and can be skimmed off.

Why does my sauerkraut need to stay submerged?

The brine blocks oxygen, which is what allows mould to grow. Cabbage exposed to air above the brine line is the most common cause of a failed batch.

Can I use iodised salt?

Non-iodised is preferred - iodine and anti-caking agents in table salt can interfere with fermentation. Plain pickling or kosher salt works well.

How long does sauerkraut last once fermented?

Refrigerated in its brine, it keeps for several months, slowly continuing to develop flavour the whole time.