How to Make Fermented Kohlrabi
Fermented kohlrabi brings out the best in this underappreciated brassica vegetable. The fermentation mellows its mild cabbage-like flavor while adding tangy complexity and probiotic benefits.
Category: Vegetables · Method: Lactic Acid · Time: 7-14d · Difficulty: 1/5 · Yield: varies · Temp: 18-22°C
History
Kohlrabi has been cultivated in Europe since the 1500s and is particularly popular in German and Eastern European cuisines. Fermenting it is a natural extension of the region's strong sauerkraut traditions.
Ingredients
- 2 medium bulbs (approx. 1.5 lbs) Kohlrabi — Peeled and trimmed
- 1.5 tbsp Sea salt — Use non-iodized salt for best results
- 4 cups Water — Filtered or dechlorinated
- 1 tsp Caraway seeds — Optional; adds traditional Eastern European flavor
Equipment
- Large jar
- Fermentation weight
- Mandoline or knife
Instructions
Prepare kohlrabi
Peel the kohlrabi deeply to remove the fibrous outer layer. Slice into 1/4-inch rounds, half-moons, or matchsticks. Thicker cuts will maintain a better crunch over long fermentation periods.
Time: 15 min
Make brine
Dissolve 1.5 tablespoons of sea salt into 4 cups of filtered water to create a ~2.5% brine solution. Stir until the water is completely clear.
Time: 5 min
Pack jar
Pack the kohlrabi tightly into a clean quart-sized glass jar, layering with caraway seeds if using. Leave at least 1-2 inches of headspace between the vegetables and the rim of the jar to allow for expansion and bubbling.
Time: 5 min
Add brine and submerge
Pour the brine over the kohlrabi until completely covered. Use a fermentation weight or a small glass lid to ensure all vegetable pieces remain submerged below the liquid line to prevent mold growth.
Time: 2 min
Ferment and gas management
Seal the jar. If using a standard lid (not an airlock), you must 'burp' the jar daily by slightly loosening the lid to release built-up carbon dioxide, then re-tightening. Store in a cool, dark place (18-22°C) for 7-14 days.
Time: 7-14 days
Fermentation Timeline
- Day 1-3: Start — Fermentation begins, slight cloudiness.
- Day 4-10: Active — Sour flavor develops.
- Day 10-14: Ready — Crisp and tangy.
Signs of Success & Spoilage
Good signs
- Active bubbling or fizzing when moved
- Cloudy brine (indicates healthy bacteria)
- Tangy, pickle-like aroma
- Kohlrabi turns slightly translucent
Warning signs
- Fuzzy mold (white, black, or green) on the surface
- Putrid or 'rotten' smell
- Slimy or mushy texture
- Pink or bright discoloration
Troubleshooting
- White film on surface
- Cause: Kahm yeast, often caused by exposure to oxygen or warmer temps. Solution: If it is a thin, flat white film (not fuzzy), it is harmless. Carefully scrape it off and ensure vegetables are fully submerged.
- Cloudy brine
- Cause: Lactic acid bacteria byproduct. Solution: This is perfectly normal and a sign of a successful fermentation.
- Soft or mushy kohlrabi
- Cause: Temperature too high or salt concentration too low. Solution: Move to a cooler spot or slightly increase salt in future batches. Ensure you peel the tough outer skin completely next time.
Storage
Refrigerated Keeps 3-4 months. Flavor deepens with time.
Health Benefits
- Vitamin C
- Fiber
- Potassium
- Probiotics
- Low calorie
Serving Suggestions
- Salads
- Slaw
- Side dish
- Grain bowls
- Snacking
Related Vegetables Ferments
Other Lactic Acid Ferments
- Kefir — Dairy
- Yogurt — Dairy
- Hot Sauce — Condiment
- Water Kefir — Beverage
- Fermented Radishes — Vegetables
- Fermented Green Beans — Vegetables
- Fermented Okra — Vegetables
- Fermented Asparagus — Vegetables