Sauerkraut calculator
Dry-salted sauerkraut: 2% rock salt on the shredded cabbage, packed into jars and left to ferment for a week or two.
Sauerkraut is shredded cabbage and 2% of its weight in salt. The salt draws out juice, the cabbage ferments under its own brine, and after a week or two in jars it is sour. Nothing else is required; caraway and carrot are options.
How it works
Weigh the shredded cabbage
A 2.5 kg head loses its outer leaves and core and shreds to about 2000 g at AniaGotuje. The salt goes on that weight: 40 g of non-iodised rock salt, 20 g per kilo. She calls 2% the minimum and the ideal at once, and allows a little more. Iodised salt is out, and so is salt with anti-caking agents.
Massage and pack
Mix the salt through, squeeze and knead until the cabbage is wet and limp, then pack it into jars pressing hard, so the juice rises over it. Fill to about 80%; the ferment foams. Lids on loosely, the jars in a dark corner at up to 19 °C. A warmer room ferments faster and rougher.
One to two weeks
Not much happens for three days, then gas. If the lids bulge, unscrew, let it out and screw them back on. Taste after a week; it is done in 7–14 days depending on the room. Then the fridge or a cold cellar at 5–15 °C, where it keeps about three months. The USDA counts in weeks: 3–4 at 21–24 °C for a full ferment.
Sources & methodology
Every percentage in this calculator traces to the published sources below — nothing is invented. Where respected sources disagree, the default sits inside the documented range.
- AniaGotuje — kapusta kiszona — The anchor: a 2.5 kg head shreds to 2000 g, salted with 40 g of rock salt — “20 g na 1 kg warzywa” (2%), her stated minimum. Five 500 ml jars, 7–14 days at up to 19 °C.
- Kwestia Smaku — kiszona kapusta — The carrot figure: a kilo of grated carrot to 10 kg of shredded cabbage (10%), salted by the cup, six weeks in the kitchen under a weight.
- USDA National Center for Home Food Preservation — Sauerkraut — The US reference: 3 tablespoons of canning salt per 5 pounds of cabbage, by volume, and the temperature table — 3–4 weeks at 70–75 °F, 5–6 weeks at 60–65 °F.
FAQ
Carrot?
Kwestia Smaku grates a kilo of carrot into 10 kg of cabbage, 10%, along with caraway and a few apples. AniaGotuje reminds you that the salt is counted on the whole vegetable mass, carrot included: 20 g per kilo of everything.
Not enough juice?
Top up with boiled, cooled water lightly salted, no more than a flat teaspoon per glass. The USDA’s top-up brine is 1½ tablespoons of salt per quart of water.
Crock or jars?
Jars for a few kilos. For a bigger batch a crock or a food-grade bag, salted in layers and pounded until the juice covers each layer, in a cellar at up to 15 °C. Kwestia Smaku’s mother uses a heavy bag with a weight on it for six weeks, and warns that in a crock the juice sinks and the top layer darkens.
Which jars?
Five of 500 ml for a 2 kg batch, about 410 g of cabbage and salt each at 80% full. Bigger jars are better than smaller ones.