Sauerkraut & Fermentation Salt Calculator (Dry Salt or Brine)

How it works

dry salting: salt = vegetable weight × % · brine: salt = water volume × % (w/v), water ≈ jar volume − 0.6 × vegetable weight · teaspoons = grams ÷ grams per teaspoon of that salt

Lacto-fermentation works by giving salt-tolerant lactic acid bacteria an advantage over everything else: around two percent salt by weight draws water out of shredded cabbage to make its own brine, suppresses spoilage organisms and keeps the pectin firm while Leuconostoc and Lactobacillus acidify the jar. Whole vegetables cannot be massaged, so they are covered with a brine whose concentration is chosen by the same logic — stronger for crunchy cucumbers and warm kitchens, weaker for a quick ferment. Because salts differ hugely in crystal size, the same teaspoon can hold anything from two and a half to six grams, which is why recipes given in spoons fail and weighing is the rule. Temperature then sets the pace: cool ferments take weeks and taste cleaner, warm ones are ready in days but soften.

Worked example

A kilogram of shredded cabbage at 2% needs 20 g of salt — about 3⅓ teaspoons of fine sea salt, but 7 teaspoons of Diamond Crystal kosher. Packed at 20 °C it should be pleasantly sour in 2–4 weeks. For cucumbers in a 1.5 L jar, the vegetables take up roughly 600 mL, so a 3.5% brine needs 31.5 g of salt in 900 mL of water.

Frequently asked questions