Getting Started with Fermentation at Home

Fermentation might sound like something requiring special equipment or laboratory conditions, but your kitchen already has everything you need. At its simplest, lacto-fermentation (the process behind sauerkraut, kimchi, pickles, and yogurt) uses naturally occurring bacteria -- primarily Lactobacillus species -- to convert sugars into lactic acid. This acid preserves the food, develops complex flavor, and produces a range of probiotic organisms. The only equipment you need is a clean jar, salt, and time.

Basic sauerkraut is the ideal starting project. Finely shred half a medium cabbage (about 500g). Combine with 10g of fine salt (2% of the cabbage weight) and massage vigorously for 5-10 minutes until the cabbage releases its own liquid. Pack tightly into a clean glass jar, pressing down until the liquid covers the cabbage completely. Weigh it down with a small bag of brine (water and salt) to keep everything submerged. Cover with cloth and leave at room temperature for 5-7 days, tasting daily from day 3. Once it tastes pleasantly sour, refrigerate.

The same principle applies to almost any vegetable. Whole fermented garlic, hot sauce, carrot and ginger pickles, fermented jalapenos -- all use the same 2% salt rule and the same submerged brine technique. Temperature affects speed: at 18-20C, fermentation takes 5-7 days; at 22-25C it may take only 3 days. The only cardinal rule is keeping vegetables below the brine surface -- anything exposed to air will mold. Once you have mastered a simple vegetable ferment, the world of kimchi, miso, and even sourdough starter becomes accessible and logical.