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Uncle Myc's 4lb Master's Mix bulk substrate bag with cartoon mushroom mascot.
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Uncle Myc's Master's Mix Bulk Substrate - 4lbs

Official Uncle Myc's Dealer Model: UN-HRD4
$24.99 USD
  • 4lbs of pre-sterilized substrate per bag
  • Scientifically balanced 50/50 soy hull and hardwood sawdust blend
  • Autoclave sterilized for immediate inoculation right out of the packaging
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VOLUME PRICING

Commercial & Bulk Purchasing

We support operations & licensed facilities with volume pricing, dedicated account managers, and custom equipment consultation.

Commercial Inquiry

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THROUGH THE Cultivator's LENS Hands-On Evaluation

  • You are moving to a soy and hardwood blend because your current substrate lacks the nutritional density to support heavy fruiting cycles.
  • You are switching to pre-sterilized bags because you have lost too many batches to contamination during your own autoclave process.

  • The 50/50 mix is the sweet spot for structural integrity, holding its shape without turning into a dense brick after hydration.
  • We keep these on hand because the sterilization process is far more reliable than anything you can pull off with a stovetop cooker.

  • Growers who swapped from DIY bulk mixes say they now see much faster colonization times and significantly higher overall yields.
  • Users who previously struggled with hidden contamination report that these sealed bags finally fixed their batch success rates.

Uncle Myc's Master's Mix Bulk Substrate - 4lbs

Gourmet and medicinal mushroom species need more structural support and nutrition than basic bulk mixes provide, and pasteurized substrates often leave contamination risk on the table. Uncle Myc's Master's Mix Bulk Substrate 4lbs solves both problems with a scientifically optimized 50% soy hull and 50% hardwood sawdust blend, sterilized in certified autoclaves rather than simply pasteurized for a genuinely clean starting point.

The 50/50 formula pairs the high nutrition of soy hulls with the structure and support of hardwood sawdust, giving species like Oyster and Lion's Mane the robust growth environment they need to produce impressive, high-yield flushes. It's ready to use straight out of the bag — no pasteurizing, no hydrating, no extra prep — just inoculate and grow.

Features

🔬
Autoclave Sterilized

Sterilized in certified autoclaves for a contamination-free start that outperforms pasteurized alternatives.

⚖️
Optimized 50/50 Formula

Combines the high nutrition of soy hulls with the structure and support of hardwood sawdust.

⏱️
Ready to Use

No preparation required — just inoculate and grow straight out of the bag.

📈
High-Yield Results

Perfectly balanced formula built for exceptional fruiting performance and generous harvests.

🍄
Versatile Application

Ideal for Oyster, Lion's Mane, and other gourmet and medicinal mushroom species.

Frequently Asked Questions

What is Master Mix Substrate? +

It's a scientifically optimized blend of 50% soy hulls and 50% hardwood sawdust, sterilized in certified autoclaves for maximum cleanliness. It's built specifically for gourmet and medicinal mushroom species that need more nutrition and structure than basic substrates provide.

How is this different from CVG substrate? +

Master Mix uses soy hulls and hardwood sawdust instead of coco coir, vermiculite, and gypsum. This composition offers higher nutrition and structural support, making it a better fit for species like Oyster and Lion's Mane compared to CVG.

Do I need to prepare the substrate before use? +

No. The substrate is fully sterilized and ready to use straight out of the bag — simply inoculate with spawn and you're ready to grow.

Which mushroom species work best with this substrate? +

This substrate is versatile enough for most gourmet and medicinal species, with particularly strong results for Oyster and Lion's Mane. The soy hull and hardwood blend gives these species the nutrition and structure they thrive on.

Why sterilize instead of pasteurize? +

Pasteurization only reduces competing organisms, while autoclave sterilization eliminates them entirely. That extra step means fewer contamination issues and more consistent colonization across every batch.

Can I use this substrate for a bulk grow with supplemented grain spawn? +

Yes. This substrate is designed to be mixed with colonized grain spawn, giving the mycelium a nutrient-dense environment to fully colonize before moving into fruiting.

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Questions About This Product?

Our specialists are happy to help. Call us or send a message and we'll get back to you within one business day (most of the time within a few hours.)

Call (360) 800-5535

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