How to Make Pea miso
Pea miso is a legume-based alternative to traditional soybean miso, made by fermenting split peas with koji. It offers similar umami depth with a unique sweet-savory character.
Category: Legumes & Soy · Method: Fungal/Mold · Time: 3-6mo · Difficulty: 3/5 · Yield: varies · Temp: 18-22°C
History
Pea miso emerged from modern fermentation experimentation, adapting traditional Japanese koji techniques to Western legumes. It's become popular among those avoiding soy.
Ingredients
- 500g Dried split peas — Green or yellow; weight before cooking.
- 500g Koji rice — Rice inoculated with Aspergillus oryzae; a 1:1 ratio with dry peas is ideal for sweet/savory balance.
- 100-120g Sea salt — Non-iodized. Target 10% of total weight (peas + koji) for long-term room temperature stability.
Equipment
- Pot
- Food processor
- Fermentation crock
- Weight
- Cheesecloth
Instructions
Cook peas
Boil split peas until very soft and easily mashed between two fingers. Drain well, reserving a small amount of cooking liquid (miso-dama) if needed for consistency.
Time: 45-60 min
Cool and Mash
Mash or process peas while warm. CRITICAL: Allow the mashed peas to cool to below 40°C (104°F) before proceeding. Adding koji to hot peas will denature the enzymes and kill the microbes.
Time: 30-60 min
Tip: Use a thermometer to ensure the temperature is safe for the koji.
Mix
Combine the cooled pea mash with the koji and salt. Mix thoroughly by hand or sturdy spoon until a uniform paste forms. If too dry, add a tablespoon of reserved cooking liquid.
Time: 15 min
Pack and Weight
Ball up the miso and throw it into a clean crock to eliminate air pockets. Level the surface. Sprinkle a thin layer of salt on top, cover with parchment paper or plastic wrap, and place a heavy weight (1-2kg) on top to keep the miso compressed and oxygen-free.
Time: 20 min
Tip: A heavy stone or a sealed bag filled with salt makes an excellent weight.
Ferment
Age in a cool, dark place for 3-12 months. Check periodically for the 'tamari' liquid pooling on top.
Time: 3-12 months
Fermentation Timeline
- Month 1-2: Start — Enzymes begin breaking down proteins.
- Month 3-6: Development — Umami deepens, color darkens.
- Month 7-12: Mature — Complex, rich miso.
Signs of Success & Spoilage
Good signs
- Darkening color (deepening yellow to amber)
- Rich, savory umami aroma
- Tamari (dark liquid) pooling on the surface
- Firm, paste-like consistency
Warning signs
- Fuzzy mold (white, green, or black) that penetrates deep into the paste
- Rancid or putrid smell
- Slimy texture
- Strong ammonia odor
Troubleshooting
- Too salty
- Cause: Insufficient aging Solution: Age longer; salt mellows over time.
Storage
Refrigerate for long-term storage Keeps 1-2 years. If surface mold appears during fermentation, simply scrape it off and discard. The miso underneath is protected by the salt and acidity. Once the desired flavor is reached, move to the fridge to slow fermentation.
Health Benefits
- Umami
- Probiotics
- Protein
- B vitamins
- Soy-free
Serving Suggestions
- Soup base
- Glazes
- Dressings
- Marinades
- Spread
Related Legumes & Soy Ferments
Other Fungal/Mold Ferments
- Miso — Condiment
- Douchi (black beans) — Legumes & Soy
- Furu (tofu cubes) — Legumes & Soy
- Tempeh gembus — Legumes & Soy
- Stinky tofu — Legumes & Soy
- Blue cheese — Dairy
- Brie — Dairy
- Camembert — Dairy