A WINTER OF MUSHROOMS

In our desire to produce an income year round on the farm, we decided to try growing mushrooms and see if it was something we would enjoy and would hopefully be worth the effort.  Mushrooms are far more complicated than I originally thought, although our only experience with growing them was from a ready to fruit block that was given to us as a gift.

Mushrooms are propagated from mycelium, mycelium is white stringy stuff you might have discovered growing in a mulch or compost pile. You need to get your hands on mycelium to grow mushrooms (more or less). The mycelium is added to a substrate (usually a grain like winter rye or bird seed), and allowed to grow and colonize the container. This substrate with colonized mycelium is called spawn.  It is basically used to expand the mycelium, sort of like growing a transplant. The spawn is then added to another container for fruiting (often a bag), which contains a different substrate (usually straw or hardwood sawdust), and occasionally a supplement (alfalfa or bran). The fruiting bag is either pasteurized or sterilized depending on the mushroom variety, and after it is cool, spawn is added.

Each mushroom is different, and even oysters vary in the conditions they thrive in. We soon discovered that blue oysters are among the easiest to grow and ordered some spawn from a company in the north east. Blue oysters grow on straw and the straw needs to be pasteurized at around 160 degrees for 90 minutes. That was done in pots on our kitchen stove (apparently I need to find a better method for doing this). There is a way to cold pasteurize the straw which we are going to try with our next batch. The straw is drained, cooled and mixed with the spawn before it is added to bags and put in the incubator. Grains and sawdust need to be processed in a pressure cooker before spawn can be added.

The incubator is basically a dark area around room temperature or higher. It is where the mycelium grows and colonizes the bag, we poke holes in the bags so they can get a little extra air while growing. Once colonized, the bags are placed in the fruiting chamber.  At the moment, our fruiting chamber is just a small, low cost, four shelf greenhouse in the basement.  Mushrooms need fresh air and high humidity (generally above 85%) so we have a tote with a fan mounted to the lid, inside the tote is a fogger.  There is a humidity control which turns on the fan and fogger when the humidity in the tent drops too low.  The whole tote is connected to the fruiting chamber with PVC pipe which delivers the fresh humid air.

We are also playing around with making our own spawn, you can buy mycelium strains in a syringe and add them to bird seed or grain and grow them out, you can also add the liquid from the syringe to a sugar liquid and allow the mycelium to grow in that. This is far more involved than we originally thought but we are really enjoying the whole process. Our plan is to produce 25 lbs of mushrooms a week by the start of the Farmers markets.  We have a long way to go.