🥬 Kimchi & Sauerkraut Calculator

For most vegetable ferments, use 1.5% to 2.5% salt by weight of your vegetables. A 2% ratio is the sweet spot for safe fermentation with great flavor and texture. For 1000g (about 2.2 lbs) of cabbage, that's 20g of salt. Using too little salt risks spoilage, while too much inhibits fermentation and makes your kraut overly salty.

Salt levels don't decrease during fermentation – if it's salty on day one, it will remain salty. The tangy flavor that develops can help mask the salt perception. If your ferment is too salty, try fermenting longer (the sourness balances the salt taste), rinsing before eating, or incorporating it into dishes where you reduce other added salt. For future batches, weigh your salt precisely using our calculator.

At room temperature (60-70°F / 16-21°C), sauerkraut typically takes 3-4 weeks for full fermentation. Kimchi ferments faster – often 3-5 days at room temperature before refrigeration. Warmer temperatures speed up fermentation but may produce softer textures. Colder temps slow it down but often yield crisper results. Taste regularly and refrigerate when the flavor is to your liking.

Contrary to popular belief, scientific studies have shown that iodized salt does not significantly inhibit lactic acid bacteria fermentation. However, the anti-caking agents in table salt can cause cloudy brine, which affects appearance. For the clearest brine and cleanest flavor, many fermenters prefer sea salt, kosher salt, pickling salt, or Himalayan pink salt. These options are free of additives that might affect your ferment's appearance.

A white, creamy film is usually kahm yeast – harmless but unpleasant-tasting. Simply skim it off and continue fermenting. However, if you see fuzzy mold (blue, black, green, or pink), that's a sign of contamination and you should discard the entire batch. The key difference: yeast is flat and creamy, mold is fuzzy and raised.

Yes, this is critical! Vegetables exposed to air are vulnerable to mold and spoilage. Use fermentation weights, a sealed plastic bag filled with brine, or even a clean plate with a weight on top to keep everything submerged. Check daily and push down any floaters. If vegetables rise above the brine, add a 2% salt solution to cover them.

Mushy ferments usually result from too little salt, fermenting at too high a temperature, or using old, wilted vegetables. Salt helps maintain crunchiness by hardening the pectin in vegetable cell walls. For crispy results: use 2-2.5% salt, ferment at cooler temperatures (60-68°F / 16-20°C), and start with fresh, firm cabbage. Soft sauerkraut is still safe to eat and works great in cooked dishes.

Taste is your best guide! When the flavor reaches your preferred level of sourness, it's done. Bubbling activity slows down as fermentation matures. For sauerkraut, many prefer 3-4 weeks at room temperature. You can also use pH strips – properly fermented vegetables reach pH 4.6 or lower. Once you're happy with the taste, refrigerate to slow further fermentation.

It's best to minimize opening the jar, as each opening introduces oxygen and potential contaminants. However, you'll need to "burp" the jar daily if using a regular lid (to release CO₂ pressure) and check that vegetables stay submerged. If using an airlock lid, you won't need to open it at all. Quick peeks for tasting are fine – just use a clean utensil each time.

When stored properly in the refrigerator with vegetables submerged in brine, fermented sauerkraut and kimchi can last for many months – often 6-12 months or longer. The flavor will continue to develop (becoming more sour) but at a much slower rate. Always use clean utensils, keep vegetables submerged, and watch for any signs of mold. If it smells and looks normal, it's safe to eat.