Grain Preparation Protocol: Commercial Scalability

Context: Standard Operating Procedure (SOP) for Whole Oats or Rye Berries. Objective: Achieve 50-55% moisture content (MC) with zero surface moisture to prevent bacterial vectoring during colonization.

Phase 1: Grain Selection & Analysis

Select grain based on cost-efficiency and inoculation points per volume.

*NSNS: No Soak, No Simmer (Millet specific).

Phase 2: Rinsing and Pre-Soak

This phase is critical for endospore germination, making sterilization effective.

1. Rinse: Dump dry grain into a 5-gallon bucket or wash tub. Rinse with tap water, agitating aggressively to remove dust, chaff, and bug fragments. Repeat until water runs clear (usually 3-4 washes).
2. Soak: Cover grain with water (fill 2-3 inches above grain line to account for expansion).
3. Gypsum Addition: Add Gypsum (Calcium Sulfate) at a ratio of 5% by dry grain weight (approx. 1 cup per 5 gallons of grain).

• Function: pH buffer and anti-caking agent.

1. Duration: Soak for 12–24 hours. This signals dormant endospores to germinate, making them susceptible to thermal destruction in the autoclave.

Phase 3: Thermal Hydration (The Simmer)

Target: Internal hydration without burst kernels.

1. Transfer: Move soaked grain to a stock pot or industrial steam kettle.
2. Boil: Bring water to a rolling boil.
3. Simmer Duration:

• Oats: 30–45 minutes.
• Rye: 15–25 minutes.

1. The "Thumb Nail" Test: Periodically scoop a few grains. You must be able to slice through the kernel with your fingernail, revealing a hydrated (white/translucent) center, but the shell must remain intact.

• Failure State: If kernels are bursting (starchy white guts exploding out), you have over-hydrated. This leads to "wet rot" (Bacillus).

Phase 4: Surface Evaporation & Bagging

Surface moisture is the #1 cause of bacterial contamination.

1. Drain: Strain grain immediately while hot. The steam helps evaporate surface moisture.
2. Spread: Layout grain on large drying screens or a clean table.
3. The Tissue Test: Place a small pile of grain on a piece of toilet paper or paper towel for 10 seconds.

• Pass: No wet spot on the paper.
• Fail: Wet spot visible. Continue drying.

1. Bagging: Load into 0.2-micron or 0.5-micron filter patch bags.

• Standard Commercial Weight: 2.5kg (approx. 5.5 lbs) or 3kg blocks.
• Jar Note: If using jars, fill to 75% capacity and use modified lids with synthetic filter discs.

Phase 5: Sterilization Cycle

Parameters for standard autoclaves or 23qt Pressure Cookers (e.g., Presto 23).

Cooling Protocol: Allow the PC/Autoclave to return to 0 PSI naturally. Do not manually vent; rapid decompression causes bags to expand and burst seals (or crack jars). Allow to cool to room temperature (approx. 8–12 hours) in front of a Laminar Flow Hood before inoculation.