Grain + Substrate Guides
In this video, you'll learn how to grow mushrooms with grain and substrate in a grow bin (aka monotub). We'll teach you everything from inoculating your grain bag, mixing your colonized grain and substrate in a grow bin, and harvesting mushrooms!
Supplies You'll Need
- Grain Bag w/ Lightning Colonization™
- Premium Manure Mushroom Substrate (x2)
- Spray bottle filled with 70% Isopropyl Alcohol
- Scotch Tape
- Syringe with 10 -20 CCs of Liquid Culture or Spores (see below for purchasing info)
- Latex Gloves
- Paper Towels
- Monotub (aka grow bin)
- Air filter patches for monotub
- Liner or an aluminum tray that fits snugly inside the monotub
- Atomized fine mist spray bottle
- Flow hood
WHERE TO BUY LIQUID CULTURE OR SPORES:
This can easily be found online from many suppliers.
Our favorite supplier is inoculatetheworld.com. Use the checkout code MUSHROOMSUPPLIES on their website for 5% off!
STEP 1: Sterilize your environment
This first step is very important! Even the smallest amount of bacteria can ruin your mushroom bag if it gets inside.
- AIR: Turn off any fans, A/Cs, or heaters.
- BODY: Wear gloves and a mask.
- WORKSTATION: Clean your workstation with a spray bottle filled with 70% isopropyl alcohol.
- GRAIN BAG: Wipe your grain bag down with the alcohol spray bottle. Do not wipe or get alcohol inside the air filter patch.
- INJECTION PORT: Leave a fresh alcohol wipe or paper towel with isopropyl alcohol over the injection port until you are ready to inject.
STEP 2: Inoculate your grain bag
- Gently knead your grain so that the moisture is evenly distributed throughout the bag. Gently tap the bag on your work surface so that all the grain settles back to the base.
- Attach the sterile needle to your syringe. Flame sterilize your syringe needle and allow it to cool.
- Carefully insert your syringe needle into the injection port and inject the bag with 10-20 CCs of liquid culture or spores. If you’re working with spores, make sure that all the fluid is injected in a single spot in the bag so the reproductive cells are near each other.
- Carefully pull the needle out the injection port and place the cap safely back on. Dispose of the needle in a designated receptacle.
- Cover the injection port with clean scotch tape to protect the bag from outside contamination. You may also place the alcohol wipe back on the injection port and allow the injection port to self-heal.
- If you’re doing multiple injections with the same needle, make sure to re-sterilize your needle with a lighter between each injection.
- Store the bag in a semi-dark room with no direct sunlight, off the ground, at about 70-78 degrees Fahrenheit.
- You will store you bag until it is 20-40% colonized (20-40% covered in white mycelium). If Using Liquid Culture: Store your bag for about 1-3 weeks. If Using Spores: Store your bag for about 2-4 weeks.
STEP 3: Shake your bag once it's 20% colonized
- Once your bag is about 20% colonized, it's time to shake it. The purpose of shaking the bag is to speed up the mushroom growth and to evenly distribute the mycelium so that all the nutrients gets consumed.
- Gently knead and shake your bag to break up the mycelium until it’s evenly distributed throughout the bag.
- After shaking the bag, place it back in storage under the same conditions as before for about another week or two, so it can finish colonizing.
STEP 4: Prep your monotub once your grain bag is fully colonized
Now that your bag is fully colonized, it's time to prep your monotub.
- Repeat the steps above under "STERILIZE YOUR ENVIRONMENT" to ensure everything is contamination free.
- Use 70% isopropyl alcohol and paper towels to sanitize scissors and your two substrate bags.
- Cover the holes on your monotub with tape or patches provided with your monotub. Then spray the inside/outside of the bin, monotub lid, and aluminum tray (monotub liner) with 70% isopropyl alcohol to sterilize the bin.
- Cut open the two substrate bags from the top and pour both bags into the aluminum tray (monotub liner).
- Gently knead and shake your grain bag to break up the mycelium until it’s evenly distributed throughout the bag.
- Cut open the grain bag from the top and pour over the substrate inside the aluminum tray.
- Massage and gently knead the grain spawn until evenly mixed together. Once mixed together, gently pat the top layer to level out the growing medium.
- Place the lid on the monotub.
- Store the monotub in a semi-dark room with no direct sunlight, temperatures at about 70-78 degrees Fahrenheit, with the bag placed at least waist-height or above.
- Keep your monotub undisturbed in these conditions until all the growing medium has become fully colonized with mycelium.
STEP 5: Prep monotub for mushroom growth
- Once the growing medium is fully colonized inside the monotub, remove any tape or patches used to cover up holes on your monotub.
- Cover the holes with air filter patches (provided with your monotub) to allow for fresh air exchange.
- Lower the temperature to 73-75 degrees Fahrenheit. Ensure the monotub has access to clean fresh air, preferably HEPA filtered.
- Pinning and fruiting should occur within the next 7-14 days.
STEP 6: Harvest mushrooms!
- Observe your monotub’s progression and watch for signs of fruiting (actual mushroom growth). The best time to harvest is when the cap has formed and just before the veil begins to tear away.
- There may be many mushrooms at different stages. Try to think of “the greater good”, and harvest your mushrooms when most of them are ready.
- Open the monotub and harvest ALL the mushrooms. Lightly twist and pull at the base of the stem to remove the mushrooms. Set the mushrooms aside on a clean plate/tray/bin/etc.
- Place the lid back on the monotub and wait another two weeks for the second flush.
- After each mushroom has been harvested, cut the bottom portion of each stem off and make sure there isn’t any growing medium on the mushroom.
- Dry your mushrooms using your preferred method.
OPTIONAL: Rehydrating your monotub for 2nd and 3rd flushes
Use this formula to calculate the amount of distilled water needed to rehydrate your growing medium for your 2nd and 3rd flushes:
Measure the wet weight of the mushrooms you just harvested and divide by 3. This is the amount of water (in mL) you'll add back into your growing medium.
Example: 300 grams of fresh mushrooms / 3 = 100 ml of distilled water.
- Use a spray water bottle to spray the inside lid of the monotub.
- Attach the lid back on and place the monotub back into storage.