Expand to Straw and Buckets
Your spent block is still living, colonized mycelium. Give it more room and fresh nutrition and it keeps fruiting for months. This is the single best way to multiply what one bag produces.
- 01
Pasteurize your straw
Fill a container with straw, pour boiling water over it, cover and hold at 160 to 180 degrees for 90 minutes. Drain and cool to room temperature. Straw should be moist, not dripping.
- 02
Break apart the spent ShroomBag block
Crumble it into chunks. The white mycelium running through it is what you are spreading.
- 03
Mix with cooled straw
Roughly 1 part spent substrate to 2 parts straw. Mix evenly so the mycelium has fresh food in every handful.
- 04
Pack into a five gallon bucket
Drill holes in the sides for air and fruiting. Do not pack too tight, it needs to breathe.
- 05
Colonize at room temperature
Cover the top loosely and store at 65 to 75 degrees. Wait 14 to 21 days for full colonization, white throughout.
- 06
Mist, give air, harvest
Once colonized, the mycelium runs to the holes. Mist 2 to 3 times daily and give fresh air. First flush in 7 to 14 days.
100 lbs of spent substrate mixed with 200 lbs of straw makes roughly 300 lbs of expanded substrate. At a conservative 0.3 lb of mushrooms per lb of substrate, that is around 90 lbs of additional mushrooms from material that cost you almost nothing. Straw runs about 6 to 12 dollars a bale at farm supply stores, and stables often give it away.
Nothing here requires buying anything. But if you want more material to expand from, a fresh kit or refill is the fastest way to stack another cycle on top of this one.