'Mastr Mix' Sterile Soyhull & Hardwood Bulk Substrate

$23.99

Increase the yield of your home-made fruiting blocks!

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In Stock. Ships in 1-2 business days.

Our premium sterilized ‘Mastr Mix’ contains a blend of hardwood sawdust, non-GMO soyhulls, and select substrate amendments. This proprietary blend is formulated for higher yields and has a pleasant, leafy, deep veggie aroma (thanks to the premium soyhulls used in our recipe).

After more than a year of development, the result is a product with a better nutritional profile for a faster mycelial run (and even better yields than the original mix mushroom growers have come to love!) ‘Mastr Mix’ is an ideal bulk substrate for use with any of our grain spawn strains.

This bulk substrate is ideal for fruiting straight from the bag in a controlled environment (like a martha tent or monotub).

Moisture content: Each bag is optimally hydrated for fast colonization times and top yields.

How to use:

  • For 3 lb. bag of inoculated grain spawn - we recommend 8-12 bags of Mastr Mix
  • For 6 lb. bag of inoculated grain spawn - we recommend 16-24 bags of Mastr Mix

(Higher inoculation rates may improve colonization times and yield.)

Best practices
  • It is best practice to wait a minimum of 1 week after arrival before using sterile substrates to ensure they were not compromised during transit. Rest assured that your purchase is 100% guaranteed. If your substrate is compromised, we will replace it.
  • We recommend clean hands, latex or nitrile gloves, and sterile technique using a still air box or flow hood to reduce the introduction of contaminants. 70% isopropyl alcohol, a scalpal or scissors and an alcohol burner are all helpful tools for an inoculation space. Please be aware of alcohol flammability and never use both alcohol and a flame inside of a still air box.
  • If using grain spawn, start by making sure the grain spawn has been thoroughly broken up. Then, slice the Mastr’s Mix bag just below the seal and add a small amount of grain spawn. Immediately reseal the Mastr’s mix bag and shake or massage the bag to evenly distribute the spawn.
  • If using liquid culture, purchase optional injection ports and stick a single port onto the center of a Mastr’s Mix bag. Once adhered, clean the port and your liquid culture syringe needle with alcohol, allowing the alcohol to air dry just before use. Using your liquid culture syringe, inject a full syringe into the block. Just as with grain, the next step is to mix the bag up to evenly distribute the mycelium. Recognize that liquid culture may take about twice as long as grain to colonize.
Storing

Mastr Mix should be stored at room temperature out of direct sunlight. No refrigeration is necessary. It can also be stored for several months before use.

Sterilization

Our Mastr Mix is sterilized in a commercial-grade autoclave. Sterility is verified using biological indicators and bacterial plate tests of the substrate from sample bags post-sterilization.

Upgrade Your Grow
Nitrile Gloves
Nitrile Gloves (+$13.99)

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NocBox Still Air Box (+$74.99)

Innoculate your grain without worry

Frequently Asked Questions

We recommend absolute beginners start with our Spray & Grow Kits, which make growing mushrooms at home super easy.

We want you to have the best possible experience with every North Spore product and guarantee free replacements within 30 days of receipt for any damaged, contaminated, or unusable product.

Absolutely! Mushroom cultivation is a great activity to do with the whole family, whether you'd like to grow indoors or outdoors. If you're new to mushrooms, we recommend starting with a Spray & Grow Kit or a Plant & Grow Kit – both make it easy to grow fresh, organic mushrooms at home.

We are vertically integrated — from culture work all the way to spawn and substrate production — ensuring a quality end product. And our staff mycologists keep up to date on all best practices in our field. Additionally, we have a dedicated QAQC team that tests every batch of grain and substrate before it’s inoculated.

Cluster of brown-capped mushrooms with long, light-colored stems against a white background.

Your Trusted Source for Premium Mushroom Growing Supplies

Whether you’re growing mushrooms at home, in your garden, or at a commercial scale, we offer everything you need to cultivate success. We start with the highest-quality OMRI-listed ingredients, mix them in our state-of-the-art facility, and inoculate them in our custom-built lab, so you can rest easy knowing your product will yield the best results.

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