Introduction: Shinty_six's Shiitake Bucket Tek
I came up with this method as a way to avoid using disposable filter patch bags in favor of 2 gallon plastic buckets, which are re-usable. There's nothing particularly new here. It's mostly bits and pieces taken from other teks, but I find it gives a better yield per pound of substrate than a traditional 5 lb block.
It may be possible to make a much bigger version of this in a 5 gallon bucket, but I haven't tried it yet.
This tek won't cover making grain spawn. For this example I've used whole oats but any type should work identically, and this tek assumes you've already gotten that far. If you need help making grain spawn, I recommend FreshCap Mushroom's excellent video on the topic.
1 Five gallon plastic bucket with lid
1 Two gallon plastic bucket with lid
1 roll Micropore tape
70% isopropyl alcohol
8 cups hardwood pellets
2 cups wheat bran
9.5 cups water
1-2 quart jars of colonized grain
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Step 1: Prepare the Bucket
Using a ~1/8" drill bit, make 18 or so holes in the bottom of the 2 gallon bucket and several ~1/4" holes spaced around the sides. The precise number and diameter of the holes is unimportant. The small holes in the bottom will allow excess water to drain out and the holes in the sides will provide gas exchange. If you already have a bucket drilled for growing oyster mushrooms you can use it as-as without further modification.
Once the holes have been drilled, clean and dry the bucket, then cover the outside of the side holes with Micropore tape. Leave the drain holes uncovered. Then, wipe the inside of the bucket and lid with isopropyl alcohol and set them aside to dry.
Step 2: Pasteurize the Substrate
Typically fruiting blocks made in filter patch bags are pressure cooked or steam sterilized. Since we can't do that with a plastic bucket, we will instead pasteurize the substrate. This does increase the chances of contamination, but if you take care to keep everything clean you should have success.
Spray down your 5 gallon bucket with isopropyl alcohol, then add the hardwood pellets, wheat bran, and boiling water. For each 2 gallon bucket you wish to make, add 8 cups of pellets, 2 cups of bran, and 9.5 cups of water. Mix the bran and pellets evenly before adding the water.
Cover the bucket and let it sit until it has cooled to at least 80 degrees Fahrenheit.
Step 3: Add Spawn and Substrate to the Bucket
Wearing nitrile gloves, scoop out a few large handfuls of your now pasteurized substrate into the 2 gallon bucket, then shake a thin layer of grain on top. Repeat this process alternating layers of substrate and grain until the bucket is full. Make sure your final (top) layer is substrate. You should be able to fit all of the substrate and spawn without packing it down.
Once the bucket is full, wipe away any loose substrate from the rim with a paper towel and cover it tightly. Mark the bucket with the date and set it aside somewhere it can drain. Leave it alone at room temperature for 8 weeks.
Unlike using bags, the bucket method doesn't let you see what's happening inside. If you feel the need to check on it, wait at least a few weeks to allow the top of the substrate to fully colonize, or else you may introduce contamination. You can take the lid off once in a while to peek, but try to keep it to a minimum.
Step 4: Fruit It! 🍄
After 8 weeks, remove the lid. The surface of the substrate should be heavily "popcorned", as shown. If you invert the bucket the block should slide out easily and be fully colonized on all sides. There probably won't be much browning except where your side-holes were, but this is fine. Move the block directly into your fruiting chamber and proceed as normal from there, treating it like any other shiitake block. For general info about fruiting shiitake mushrooms, watch this video.