How To Inoculate A Sterilized Grain Bag
This injection should be done in a still-air environment like a glovebox. But if you wish to do it in open air, you can do so. But you should turn off your heater or AC an hour before inoculating the bags to reduce airborne contaminants. You should also work in a small, clean room with the door and windows closed to reduce airflow.
Steps to Take
Step 1: Prepare the grain bag for injection with mycelial culture or mushroom spores in a spore syringe. Pull apart the gussets on the bag to the sealed top. Ensure that the bag is well-inflated so the filter has enough room for breathing. Pressing the filter against the plastic of the bag will limit the gas exchange during the colonization phase and disturb the colonization process.
Step 2: Put on your pair of gloves. Use a sterile alcohol swab to clean the area you will inject into.
Step 3: Take your syringe and flame it for about 15 seconds. You can use an alcohol burner to flame the needle so there won’t be any soot or residue on the needle. You can also use a lighter, but you must wipe off any lighter soot that is on the needle with a sterile alcohol swab after sterilizing the needle with flames.
After the needle of the syringe is flamed, press down the syringe plunger to bring out a little quantity of solution down the needle to cool the flamed needle down.
Step 4: Take 2-3 ccs of culture solution or spore and use it to inoculate the bag through the self-healing injection port. Apply a small piece of tape to cover the injection point.
Step 5: Set the grain bag in a place where it won’t be disturbed. It could be in a dark place or a place with light. Ensure that the temperature of the place remains between 75°F and 81°F. Within 3 to 10 days after inoculation, you’ll start to see some signs of growth. Do not disturb the bag within this period. Keep the bag in an upright position with enough space for breathing between the filter and the plastic of the bag. The bag must have enough space to breathe.
Step 6: After about 3 to 4 weeks, the mycelium will have colonized about 70-75% of the bag.
Step 7: Once the mycelium has colonized up to 70-75% of the bag, use your hands to break up the grain through the outside of the bag. Breaking up the grain will make the mycelium well distributed and hasten the last phase of colonization. Don’t break the grain until the mycelial colonization has reached at least 70%. If you do it before the right time, it will impair the growth.
Step 8: The mycelium will take a lot of days to recover after you break it. Within 3 to 7 days after breaking up the mycelium, the mycelium will colonize 100% of the bag. At this point, it is time to spawn the colonized grain to a bulk substrate.
Bulk Tub Substrate Phase
Once the inoculated grain spawn has attained 100% mycelial colonization, you can now spawn it to a bulk substrate. Remember that once the bag has been completely colonized with mycelium and you can’t see any uncolonized grain, you should break up the grain with your hands outside the bag. Ensure that the grain gets broken up thoroughly.
The recommended spawn ratio is 5 pounds of already pasteurized mushroom compost with 2 pounds of grain spawn that has been colonized. Take the bag of colonized grain that you broke up and cut it off directly below the filter patch using a pair of scissors.
Take the 1-pound grain bag and pour it into 5 pounds of mushroom compost. Add another 1 pound of grain bag and pour it into the 5 pounds of mushroom compost. This will give you 2 pounds of colonized grain spawn for 5 pounds of substrate.
Mix the grain and compost mixture through the outside of the bag. Ensure that the mixture is well-mixed and the grain distributes evenly through the bag.
You can add the mixed substrate to a modified plastic bin or any other homemade fruiting chamber. You can also add the mixed substrate to mushroom grow bags. It’s your choice. Any container works.
But we use mushroom grow bags as they are more convenient. So, all the steps performed in the rest of this tutorial are conducted using grow bags.
You need a clean, room with limited airflow for the rest of these procedures. Ensure that you wear your pair of gloves. Pour half of the 5 pounds of substrate and mixed grain into a new filter-patch bag and pour the other half into another filter-patch bag.
Mark the two inches from the top of the bag and seal the filter-patch bag with a tube and mushroom bag clamp at that point.
Place the bag in a dark place with a temperature between 75°F and 81°F. Try not to move or touch the bag within this period. Do not open the bag until the colonization phase is complete. It should take about 5 to 10 days for the substrate to get completely colonized with mycelium. Colonization is complete when the substrate turns completely white. Once the substrate is completely colonized, you can introduce the bag to the necessary conditions for fruiting.
Casing and Fruiting
It’s time to apply the mushroom casing mixture to the colonized substrate. Massage the outside of the bag containing the casing mixture to loosen the casing mixture. Use a pair of scissors to cut off the bag containing the casing mixture below the filter patch. Remove the mushroom bag clamp from the bag containing the substrate that has been colonized and dump a little casing mixture into the bag with the block of colonized substrate.
You need to form a 0.5-0.75 inch casing layer on top of the colonized substrate.
Spread the casing mixture into a uniform layer across the top of the colonized substrate with your gloved hands. Ensure that the casing remains loose and do not pat it down. Take a bag clamp and reseal the bag of colonized substrate with it. Do not pat down the casing. It should be a bit loose. Use the bag clamp to seal the bag of colonized substrate again. Put the cased substrate back in a dark place and watch it closely for some days till it gets fully colonized. Once you see that the subsurface of the casing layer has been fully permeated with mycelium, you can introduce the bag to fruiting conditions.
Introducing the Bag to Fruiting Conditions
Step 1: It’s time to introduce the bag to fruiting conditions. You are going to introduce the bag to a specific lighting cycle. The bag will be kept in an area with a temperature between 60°F and 80°F. But the temperature can fluctuate depending on the mushroom species. The best light source is a full spectrum fluorescent spiral bulb. This is a direct source of light that will grow your mushroom well. The more direct the light source, the better the growth of your mushrooms. You can leave the light on for 24 hours each day or you can operate a 12-hours on, 12 hours off schedule.
Step 2: You need to mist the colonized substrate once per day for the duration of the fruiting stage. Remove the clamp from the bag and use a clean water bottle to mist the substrate. If you hold the nozzle of the bottle beneath the filter when spraying it, the filter won’t get wet. 5 or 6 sprays of water are enough. You shouldn’t soak the colonized substrate or leave any body of water on it. You just want to spray a little water on it. If you mistakenly have too much water in the bag, pour the water out while taking care not to wet the filter.
Step 3: Fan the bag of substrate immediately after misting it. Move the gussets of the bag in and out steadily, like a fan. This will bring in fresh air and take out carbon dioxide. Fan each bag for about one and a half minutes. Use the mushroom bag clamp to reseal the bag of substrate after fanning it. The bag of substrate should be misted and fanned every day until the substrate no longer produces mushrooms. Any day that you see that the substrate is moist, you can leave it without misting it.
Step 4: 5 to 10 days after the bag has been introduced to fruiting and subjected to a light cycle, you’ll start to see primordia. Primordia are tiny pinheads that turn to mushrooms.
Step 5: Within a few days, the primordia will turn to pins. After another few days, the mushroom veils will start to open up. Once most of the mushroom caps have opened up, you can now pick them. With gloved hands, pick the mushrooms by grabbing them from the base and rooting them up. Take care not to leave mushroom fruitbodies behind as these could rot and cause contamination.
Step 6: Once all the mushrooms have been picked, remove all pieces of mushroom fruitbodies from the substrate. Now, you can mist, fan, and reseal the grow bag with a clamp. Put the grow bag back under the lighting schedule and watch for the next flush. Continue to mist and fan the bag every day. You should get about four to five flushes from the substrate until it is spent or no longer productive. You should harvest mushrooms every seven to ten days.