Blue Oyster Sterile Bulk Substrate
Pleurotus ostreatus
Quantity
What's in the bag
5lb Sterile Substrate
0.2μm Filter Patch
Instruction Card
Viable culture guaranteed. If it arrives damaged, dead, or visibly contaminated, contact us within 48 hours with photos and we'll arrange a replacement or refund.
Substrate Specs
Bag Size
5 lb — sterile hardwood substrate
Colonization
10–16 days once inoculated
Sterilization
Autoclaved 15 PSI / 120 min — verified per batch with biological indicators + temp/pressure logging
Moisture
~60% — hydrated and ready for spawn
Recommended Inoculation
1 lb colonized grain spawn per 5 lb bag (spawn sold separately)
Shelf Life
2–3 months, stored cool and dark
Sterile, autoclaved hardwood substrate for growers who already have colonized grain spawn on hand — no injection port here, just open and mix. Blue Oyster's forgiving, aggressive colonization style makes this the easiest bulk substrate to learn hand-mixing technique on.
Every bag is sterilized at 15 PSI and batch-tested with biological indicators before it ships. Mix in 1lb of colonized grain spawn per 5lb bag, incubate, then fruit from the same container.
Don't have grain spawn yet? Pair this with one of our Grain Bags and a Blue Oyster Liquid Culture syringe.
Each bag: 5lb sterile hardwood substrate · 0.2-micron filter patch · shrooms instruction card. Store cool and dark until use.