Step 1: Wash cabbage thoroughly. Remove outer leaves and core. Shred cabbage finely using a knife, mandoline, or food processor.
Step 2: In a large bowl, combine shredded cabbage and salt. Vigorously massage for 10-15 minutes until cabbage is wilted and a generous amount of brine has collected.
Step 3: Tightly pack the cabbage and brine into clean, sterilized wide-mouth glass jars, pressing down to remove air pockets. Ensure cabbage is fully submerged in brine, leaving 1-2 inches of headspace.
Step 4: Place a fermentation weight or a smaller jar filled with water on top of the cabbage to keep it submerged below the brine level at all times.
Step 5: Loosely cover jars with lids or use airlocks. Store in a cool, dark place (60-70°F/15-21°C) for 2 to 4 weeks. Bubbles will indicate active fermentation.
Step 6: Periodically check for kahm yeast (thin white film) and skim if present. Taste after 2 weeks; continue fermenting for a stronger flavor if desired. Discard if any fuzzy mold appears.
Step 7: Once desired tanginess is reached, remove weights, seal jars tightly, and transfer to the refrigerator. This slows fermentation and preserves the sauerkraut for several months.