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Spencer's Shroomery

5lb Master’s Mix Substrate Bag

Regular price $18.00 USD
Regular price $0.00 USD Sale price $18.00 USD
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See our bulk section for discounted rates

5lb sterile substrate bag for mushroom cultivation. Each bag is filled with Master's Mix sourced from Mushroom Media Online. Master's Mix is a 50/50 mixture of soybean hulls (agricultural waste) and oak hardwood pellets. Master's Mix has become an industry standard for producing hardwood-loving mushroom species such as Lion's Mane.

  • LARGE YIELDS: High-quality substrate makes it a breeze to reach 100% biological efficiency, ensuring large yields from gourmet wood-lovers.
  • FAST FRUITING: High nutrient content provides everything your mushrooms need for large, fast flushes. Just colonize and watch the pins explode from your substrate!
  • PERFECTLY HYDRATED: We know how frustrating it is trying to grow mushrooms in an over-hydrated or bone-dry substrate. We've honed our procedures to get the perfect hydration every time. 
  • BUY WITH CONFIDENCE: Here at Spencer's Shroomery, our game is growing mushrooms. We don't sell anything we don't use ourselves! Spencer’s Shroomery is committed to providing our customers with high-quality products. Customer service is always our top priority. If you have any questions, concerns, or complaints do not hesitate to contact us and we will be happy to help solve any issues!


  • 0.2 Micron filter patch
  • 5+ lbs perfectly hydrated Master's Mix (50% hardwood, 50% soybean hulls)
  • Sterilized at 15psi for 2.5hrs
  • Impulse sealed
  • 100% satisfaction guaranteed or your money back

Every bag is sealed to preserve moisture and sterile conditions within the bag. Each bag is thoroughly inspected for quality before leaving storage. 

Please observe aspectic technique when inoculating bulk substrate bags.

*All substrate supplies are made to order, please allow 1-2 weeks for production and shipping.