Growing mushrooms at home
For the last few years, I have been using wheat as my base for grain spawn. Rye grain is what most people start with, but almost any whole grain can be used, I would advise you to just use what's cheapest and available in your area. Wheat costs me $25 per 25kg bag. Barley and Oats are also good and cheap grains to use.
I don't soak wheat before cooking, All I do is wash as much dirt off as possible and simply boil for15 minutes, pour off the water and drain and let the excess water steam off. Doing it this way I have found I get a lot less burst kernels, the centre of the grain will be dry but the water on the outside of the grain will be forced into the centre of the grain during pressure cooking giving you a very dry grain on the outside while retaining moisture on the inside. During the boiling prosses I also add 3/4 a cup of gypsum per 20 cups of dry wheat which stops caking and adds some nutrients mushroom mycelium need for healthy growth. I have also been experimenting using vermiculite in the grain as well to stop excess water produced by the mycelium’s biological processes from forming at the bottom of the grain jars spreading it evenly back through the spawn. The drier you can keep the grain the less likely contaminations will occur.
Just for those of you interested if you let grain start to germinate Alpha Amylase is released from the kernel which starts breaking down the starches to make glucose and other sugars which may lead to easier contamination of green mold later on in your project, if your making an alcoholic mash for yeast this is beneficial but not when growing mushrooms.
A pressure cooker/caner is the only real piece of equipment I would consider essential if your planning to start growing mushrooms at home, everything else can be built upon later and you can work around ways to grow mushrooms fairly easily with the use of a homemade glove box and just keeping everything as sterile as you can with alcohol.
Bags-vessels grain spawn and substrate
On a budget use any vessels you can get your hands on. When I first started, I went around asking people I knew to get old jars with metal lids, olive, jam, pickle jars and just modify them to work for you. If you have a bit more $ to splash around you can order jars from several NZ wholesale suppliers for good prices, I have always bought jars from Arthur Holmes in Petone Wellington.
Another option is gusseted Cellophane bags. The upside is they are pressure cooker safe up to 20psi and very cheap from packaging suppliers I use Packaging House in Lower Hutt, they also have an amount of gas exchange through the actual material so no need for a filter patch. The downside is they are not a true plastic but made from wood-based cellulose so you will need to use spawn as soon as possible or the mushroom mycelium will start to break down the bags for their dinner. Experiments I did on these bags showed that if I made an artificial shiitake log the block was about ready for fruiting when the bag started breaking down and becoming fragile.
Logs for wood loving species
Most hardwood species can be used, the most comon in NZ is poplar, willow, prunus species, Gum, apple and other flowering and fruiting trees. When using willow, try to avoid using green wood, another words only use winter cut logs as the bark is less likely to come off.
Artificial logs are a bit mor time consuming but will give you faster and more acurate results. You definately need a pressure caner/cooker for this even if you can only get your hands on a 5psi caner, use it.
Makeing your own alcohol for sterilising
I much prefer using ethanol for sterilising. It is much less toxic and fumy compared to isopropyl and is in fact better at killing bacteria and other contaminants, isopropyl can be deadly if you breath too much of the fumes. With ethanol you can get drunk breathing in the fumes so allow good ventilation when using it. I generally wear a mask capable of stopping the ethanol getting into my lungs. The cost of making my own alcohol is about $3 per litre so I can afford to spray a bit more around without too much concern about cost. I leave my flow hood running for 2 hours before use giving ample time for the alcohol to evaporate and disperse. Whatever alcohol you use watch out for signs of rapid heart rate and disorientation, hold your breath and leave the room quickly after you have sprayed and wear a suitable mask. When distilling take off the first 100mls at least, the first alcohol that comes off is mainly methanol which can be absorbed though the skin.
You should be able to buy a still at most home brew shops. Shop around as prices for the same still can vary. I use a Turbo500 https://www.youtube.com/user/2dstill There are also smaller cheaper stills available, just go for one that suits your needs.