a simple and easy to follow tek for growing mushrooms on straw.
Heat a tub of water. The 12-gallon metal washtubs by Brinkmann at Home Depot (take one of the metal trashcan lids too if can get away with it) work great. Use a roast thermometer ($2) for this temp range.
While that's heating--it'll take awhile even on two or four burners at once--load up a strong laundry bag with wheat straw (bright yellow in color). Walmart around here sells an industrial one for $5. Alfalfa (greenish color straw-like stuff) beyond about 20% of the mix will cause contaminants. Push the straw tight in the bag.
Once the water is hot, put the laundry bag full of straw (see TIP 2) in the water. Place a heavy weight or flat cement block ($1) on it to keep all the straw submerged.
Cook at 160-180?F for 1 to 2 hours. DO NOT exceed these temperatures! If you do, you risk a bacterial bloom that will lead to disaster. 1 hour 15 minutes at 170?F is just perfect.
While this is cooking, put one of your oven racks over your kitchen sink.
Once it has cooked, lift the laundry bag out of the water and rush it over to the oven rack over the sink to drain. The oven rack should keep it suspended above the sink so it's not sitting in its own drainage.
Let drain and cool for an hour or two (this will depend on how much you had in the bag).
Once cooled and drained, put the straw in a basket or something so you can easily get to it. Before spawning the straw must be totally cool. If it is hot, you'll sterilize some or all of the grain and almost certainly fail.
Use a tub that will be high enough for fruiting when the time comes because you don't want to have to build a tent for it! Those 35 or 45-gallon tubs by Sterilite or Rubbermaid are perfect for a few square foot of cropping surface, or build your own tray as large as you'd like. Lay a layer of straw down then sprinkle some colonized birdseed cake EVENLY over the surface. Remember, each grain can serve as an inoculation point so very small pieces are desirable. Rubber gloves are recommended by not required.
Lay another layer of straw, more birdseed cake crumble, etc, until you've laid between 5 to 10 inches of straw.
With your fist, push down the straw with all your body weight all over the tub. The straw should be at least 4 inches of even depth and pushed down as well as possible.
Lay a piece of clear plastic wrap (3 mil furniture wrap works well) cut slightly larger than the surface centered over the straw. Now, just as you would tuck a child in bed, tuck in the edges of the plastic down in to the tub. The idea here is to make the plastic touch all of the straw because large air pockets under the plastic tend to dry out the straw making it colonize slowly.
The plastic needs lots of holes poked through it! I'd recommend 1/8th inch hole every 1 to 2 square inches or the equivalent in small holes. One way to make them is to heat a fork with a torch and melt lots of tiny ones. Alternatively, you could have drilled them through a piece of highly folded plastic wrap before you laid it (easiest method if you have a drill). This method allows one to drill one hole making dozens.
Let the straw colonize at room temp (75?F) for 10 to 14 days (see TIP 1). It'll be ready to case after it is totally colonized over the surface. It will generate a lot of heat, so do not incubate except to keep the room temperature in the mid-70s! Self-heating will keep the tray in the lower to mid 80s assuming the room is in the mid-70s.
Take the plastic off. Sprinkle the casing mix (see TIP 3) on the tray at a depth of 1/2 to 1 inch. Do not pack the casing mix down! Replace the hole-covered plastic lightly laying it directly over the casing. Do not tuck the plastic in this time. Do not pack down on the casing in any way. If there are large holes around the edges of the plastic, tape the sides against the tub.
In one to two weeks or even less (depending on the depth), the casing should be colonized. Now, take the plastic off, cover the top of the tub with a new sheet of hole-free plastic, begin the light cycle, and hook up a cool mist humidifier via ShroomGod's Humidifier Tek.
THAT'S IT! Expect between 90 to 180 dried grams (that's 2 to 4 wet pounds) per square foot given a 6-inch deep bed and about 4 flushes.
TIP 1: If you buy a panel of "egg crate" light diffuser material--any decent hardware store will care this in the lighting department--then you can really increase the how evenly and fast the tray colonizes. All you need to do is cut the material to the size of the tray surface, place it over the plastic, and weigh it down with one cinder block every 2 to 3 square feet. You can remove this after the straw has colonized before the casing is applied. This weight will give more compression of the straw making it colonize faster and more evenly. Take care to not cover many of the air holes.
TIP 2: Cutting up the straw prior to pasteurization in to 1 to 3 inches pieces makes TIP 1 not really needed. Cutting is just too much hassle for me, but maybe you have something to cut up massive amounts of straw quickly (like a mulching mower or chipper/shredder).
TIP 3: A great casing mix is 8 parts peat moss, 8 parts vermiculite, 1 part lime flour. Saturate 80% of it with tap water then mix in the remaining 20% dry to get the moisture right. You can pasteurize the casing by cooking it at 160?F (that's the warm setting on most ovens) covered with foil for 2 hours. Do not sterilize the casing. Many respectable mycologists discourage sterilization of the casing.