How much liquid culture should I inject per jar?

Use roughly 1 to 2 cc of liquid culture per pint of grain. More culture means faster, more reliable colonization, but a single syringe can still inoculate several jars when your technique is clean.

Why do I have to pressure-sterilize grain?

Hydrated grain carries bacterial and fungal endospores that survive a rolling boil. Only sustained pressure at 15 PSI reaches the temperature needed to kill them. Rinsing and simmering hydrate the grain but do not sterilize it.

What does healthy colonization look like?

Clean white, rhizomorphic or fluffy mycelium spreading from each injection point. Any green, black, pink, orange, or gray growth, or any sour or off smell, means contamination - seal the jar and dispose of it outside.

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Cultivation Guide

Inoculating Grain With Liquid Culture

Liquid culture lets you expand Redbird genetics into grain spawn at home. Done with clean technique, one syringe can colonize multiple jars. Done carelessly, you'll lose the whole batch to contamination. The difference is entirely in your preparation and your sterile technique.

This guide assumes you are inoculating sterilized grain in jars fitted with a self-healing injection port and a filter patch for gas exchange.

Hydrate the Grain

Use a hard grain such as rye, wheat, or oats.

1
Rinse the grain under cool water until the water runs clear, working out loose dust and debris.
2
Soak the grain in clean water for 12 to 24 hours at room temperature. This begins hydrating the kernels through to the center, which is essential - dry centers survive sterilization and become contamination sites later.
3
After soaking, bring the grain and soak water to a simmer for 10 to 15 minutes, until the kernels are hydrated but not split or mushy. Split grain turns gummy and colonizes poorly.

Drain and Surface-Dry

1
Drain the grain thoroughly in a colander. Excess free water at the bottom of a jar causes anaerobic conditions and contamination.
2
Spread the grain out and let the surface moisture evaporate for 30 to 60 minutes, until the kernels are tacky but no longer wet to the touch. The goal is fully hydrated kernels with a dry exterior - what growers call “field capacity.”

Sterilize the Grain

Draining and rinsing do NOT sterilize grain. Hydrated grain is full of bacterial and fungal endospores that survive boiling. They must be killed under pressure.

1
Load the drained grain into clean jars, filling no more than two-thirds full to leave room for shaking later.
2
Pressure-sterilize the jars at 15 PSI for 90 minutes to 2 hours. A pressure cooker or pressure canner is required - an ordinary pot of boiling water cannot reach the temperature needed to kill endospores.
3
Let the jars cool completely to room temperature before inoculating, ideally overnight. Injecting warm grain will kill the culture.

Inoculate With Sterile Technique

Contamination almost always enters at this step. Slow down and follow it exactly.

1
Work in a still-air box or in front of a flow hood. Never inoculate in open, moving air.
2
Wipe your work surface and the jar's injection port with 70% isopropyl alcohol. Let it flash off.
3
Shake the sealed liquid culture syringe gently to distribute the mycelium evenly through the liquid.
4
Attach one of the included sterile needles, keeping it capped until the moment of use.
5
Flame the needle to glowing red, then let it cool fully in still air for several seconds. Injecting with a hot needle kills culture on contact.
6
Insert the needle through the alcohol-wiped injection port and inject roughly 1 to 2 cc of liquid culture per pint of grain.
7
Withdraw the needle, re-flame it to red, and let it cool before moving to the next jar. Never set a bare needle down on any surface.
8
Once inoculated, leave the jars undisturbed in a clean, room-temperature spot out of direct light. Do not shake until you see healthy white growth established at the injection points, usually within several days.

What Healthy Colonization Looks Like

Clean white, rhizomorphic or fluffy mycelium spreading from each injection point. Once colonies are established and growing, a gentle shake to distribute the grain speeds full colonization.

Any green, black, pink, orange, or gray growth, or any sour or off smell, means contamination. Do not open a contaminated jar indoors - seal it and dispose of it outside. Contamination at this stage is almost always a technique or sterilization issue, not the culture itself.

Common questions

How much liquid culture should I inject per jar?: Use roughly 1 to 2 cc of liquid culture per pint of grain. More culture means faster, more reliable colonization, but a single syringe can still inoculate several jars when your technique is clean.
Why do I have to pressure-sterilize grain?: Hydrated grain carries bacterial and fungal endospores that survive a rolling boil. Only sustained pressure at 15 PSI reaches the temperature needed to kill them. Rinsing and simmering hydrate the grain but do not sterilize it.
What does healthy colonization look like?: Clean white, rhizomorphic or fluffy mycelium spreading from each injection point. Any green, black, pink, orange, or gray growth, or any sour or off smell, means contamination - seal the jar and dispose of it outside.

Start with provenance

Every jar of grain spawn is only as good as the culture behind it.

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