Rye Grain Master Spawn

How do I prepare it?

Soak and simmer rye grains until hydrated, drain thoroughly, mix with gypsum, load into jars, and sterilize.

1. Rinse rye grain thoroughly and soak it in cold water for 12–18 hours.
2. Drain the grains and simmer them in fresh water for 10–15 minutes until they reach 55–60% hydration.
3. Drain the grains completely and allow steam-drying for 20–30 minutes.
4. Mix in gypsum and lime to prevent clumping and stabilize pH.
5. Load hydrated grains into sterilizable jars at 70–80% capacity.
6. Sterilize grain jars at 15 PSI for 90 minutes.
7. Let cool fully before inoculating with existing grain spawn or liquid culture.
8. Shake jars after 25–30% colonization to speed up distribution.
9. Once fully colonized, use as master grain spawn for bulk substrate.