Lacto-Fermentation
Lacto-fermentation is preservation through acid. Lactobacillus bacteria consume sugars and produce lactic acid. The acid drops pH below 4.6, where most pathogens can’t survive. Vegetables that would rot in days last for months. No refrigeration, no canning, no vinegar — just salt, time, and the bacteria already present.
The basic technique is simple. Submerge vegetables in 2-3% brine (20-30 grams salt per liter water). Keep them below the surface — Lactobacillus thrives without oxygen, but molds need air. Wait. Bubbling indicates active fermentation. Taste daily. When the flavor reaches where you want it, refrigerate to slow the process.
The transformation produces complexity no simple preservation can match. Cabbage becomes sauerkraut: tangy, funky, alive. Cucumbers become pickles with depth that vinegar brining can’t achieve. Kimchi develops its layered heat and umami. The bacteria aren’t just preserving — they’re cooking.
Nutrient profiles improve. Fermentation increases B-vitamin content. It breaks down anti-nutrients like phytic acid that interfere with mineral absorption. The probiotics themselves may benefit gut health, though the research is still early and complicated. What’s clear: fermented vegetables aren’t just preserved — they’re transformed.
Salt is the selective pressure. Most bacteria can’t tolerate saline environments. Lactobacillus can. This gives them competitive advantage before the acid establishes itself. Too little salt and other organisms dominate, creating off-flavors or safety risks. Too much and even Lactobacillus struggles. The 2-3% range is the sweet spot, established through millennia of practice.
Temperature matters too. Faster fermentation at warmer temperatures produces faster acid development but less complexity. Slower, cooler fermentation (60-70°F) creates more nuanced flavors. Many traditional ferments are seasonal — made in fall, when cooler temperatures slow the process and vegetables are abundant.
The margin for error is wider than people assume. Lactobacillus dominates in salted vegetables because the conditions favor it. Contamination failures are visible — mold on the surface, off-smells, slime. If it smells like pickles, it’s safe. Generations of people fermented vegetables before germ theory, guided by sensory evaluation rather than pH meters.
This doesn’t mean safety is guaranteed. Low-salt ferments, especially with protein-rich additions, carry more risk. Botulism is theoretically possible in low-acid anaerobic environments. The traditional recipes are safe because they evolved to be — but inventing new recipes requires understanding the principles, not just copying procedures.
Related: [[fermentation]], [[wild-fermentation]], [[starter-cultures]]