SHROOMFOLK

STERILIZED GRAIN SPAWN TUBS

Your Kit Includes

✓ Sterilized Grain Spawn Tubs     (vacuum sealed)

✓ Incubation Bag     (filtered for air exchange)

 

BEFORE YOU BEGIN Your grain tubs arrive vacuum sealed to maintain sterility. Do not open the seal until you are ready to inoculate. Once opened, inoculate immediately. Sealed tubs have a shelf life of approximately 60 days when stored at room temperature out of direct sunlight.

 

1	PREP YOUR WORKSPACE

 

•     Clean your work surface with 70% isopropyl alcohol.

•     Wear nitrile gloves and a face mask.

•     Work in a still, draft-free room. Turn off fans and close windows.

•     Have your culture source (liquid culture syringe, agar wedge, or colonized grain) ready before opening the tubs.

 

⚠️	Do not open the vacuum seal until everything is prepped and ready. Once opened, inoculate immediately.

 

2

INOCULATE

 

Choose your inoculation method below. For liquid culture, the lid stays on and you inject through the injection port. For agar or grain transfers, you remove the lid, perform the transfer, then put the same lid back on.

 

  LIQUID CULTURE TO GRAIN

Wipe the injection port with an alcohol wipe. Shake your LC syringe for 30 seconds. Insert the needle through the injection port and inject 2-5ml of liquid culture onto the grain. Withdraw the needle. Swirl the tub gently to distribute the culture across the grain. The lid stays on the entire time.

 

  AGAR TO GRAIN

Break the vacuum seal and remove the lid. Set the lid upside down on a sanitized surface. Using a sterilized scalpel, cut a small wedge of colonized agar (about the size of a nickel) and drop it onto the grain surface. Immediately place the same lid back on the tub.

 

  GRAIN TO GRAIN

Break the vacuum seal and remove the lid. Set the lid upside down on a sanitized surface. Open your fully colonized grain source. Pour or scoop a small amount of colonized grain (about 10-15% of the fresh tub’s volume) onto the fresh grain. Immediately place the same lid back on the tub. Shake to distribute.

 

3

INCUBATE

 

Place your inoculated tubs inside the provided incubation bag. The bag maintains humidity around the tubs while allowing fresh air exchange through the filtered material.

 

⚠️	Do not seal the incubation bag airtight. The bag needs airflow.

 

•     Store in complete darkness at 70-75°F (21-24°C). A closet or cabinet works well.

•     Do not open the tubs during colonization.

•     Check progress every few days by looking through the tub walls.

 

4

WAIT

 

Colonization times vary depending on your inoculation method:

 

LIQUID CULTURE 2-4 weeks

AGAR TRANSFER 3-5 weeks

GRAIN TO GRAIN 1-3 weeks

 

Fully Colonized = Ready to Use

•     Entire grain surface appears bright white with no uncolonized patches.

•     Dense, fluffy mycelium covers all grains.

•     Grain may clump together in a solid mass — this is normal and indicates strong colonization.

 

5	FULLY COLONIZED — NOW WHAT?

 

You now have colonized grain spawn. Here’s what to do with it:

 

  INOCULATE BULK SUBSTRATE

Mix your colonized grain spawn into a sterilized or pasteurized bulk substrate (CVG, hardwood, Master’s Mix) at a 1:1 ratio. Pack into a monotub, grow bag, or Shroomfolk Microbox container. Initiate fruiting conditions once fully colonized.

 

  GRAIN-TO-GRAIN TRANSFER

Take a portion of your colonized grain and transfer it into fresh sterilized grain tubs to expand your spawn supply. One fully colonized tub can inoculate 5-10 fresh tubs.

 

⚠️	Use your colonized spawn within 1-2 weeks of full colonization. The longer it sits after colonizing, the more the mycelium ages and vigor decreases.

 

Questions? Email support@shroomfolk.com