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Bulk Substrate Instructions

Bulk Substrate Instructions


This substrate should be inoculated with “fully colonized” grain spawn only. Injecting spores or liquid culture directly into this substrate will cause contamination and will not work. Do not use as casing.

This substrate can be used in mono tubs and trays. You can also use the filter bag as a growing bag but this won’t be as efficient.
This product requires basic knowledge of mushroom cultivation. If you are a beginner, please do your research first on spore prints, grain spawn, bulk substrate teks, monotubs, mushroom trays and fruiting chambers.
This product and instructions are intended for the cultivation of legal edible mushrooms.

1) Inspect your vacuum sealed bag for contamination and mold.  If you see contamination, don’t use the soil; contact us before going any further.

2) Wipe all surfaces, your hands, tools and containers with rubbing alcohol before you start and as needed going forward.

3) Cut the top of the vacuum sealed soil bag and remove the filter bag.Unfold the filter bag and loosen the soil by squeezing the filter bag with your hands.

4) At this point you have two options:
a. You can use the filter bag the substrate came in and mix the grain spawn into the bag, shake and seal the filter bag. And then continue to Step 10.
b. Use your own tub or tray. We recommend this as this provides better yield.

5) We highly advise that you have your grain spawn and tub or trays ready at this point so that you can finish the next step as soon as possible, reducing the risk of contamination from the environment.

6) Wipe your tub with alcohol thoroughly. Line your container with a clean plastic sheet. Dump the soil into the tub. The final substrate in your container should be between 2-4 inches deep depending on the size/volume of your container. We recommend 25qt monotub per 5lb of substrate; or 15-16qt container per 5lb of substrate for incubation and then placing it in a big enough fruiting chamber (e.g. shotgun fruiting chamber) or humidity tent for fruiting.

7) Make sure to loosen any remaining clumps in the substrate and your substrate is evenly mixed, looking uniform and no dry patches visible. The substrate should be fluffy and not compacted.

 8) Break your grain spawn into individual grains and mix the grain spawn into your substrate evenly with an alcohol wiped tool/spoon. We recommend using 30%-50% grain spawn as compared to the weight of the substrate. So, this 5lb substrate will need a minimum of 1.5lb of grain spawn.

9) Make sure the substrate is evenly distributed in your tub and the surface is flat.

10) Your substrate is now ready for incubation. Place your tub/trays or grow bag in a dark room/closet where the temperature is between 70-75°F.

11) Once the incubation starts, it should take about 10-14 days for the substrate to be fully colonized by the mycelium. When the entire substrate is white, including the top of the substrate, you are ready to start fruiting your mushrooms in a fruiting chamber with high humidity and frequent air exchange.

Good Luck and Happy Harvest!