How to Grow Fresh Oyster Mushrooms at Home
Updated: Nov 17, 2019
Home Cultivation of Oyster Mushrooms
Growing oyster mushrooms at home can be rewarding and fun. It's nice to see something you created from start to finish turn into your dinner. You'll also save money, as oyster mushrooms can be as much as $15 a pound! This is a guide to growing your own oyster mushrooms at home.
Oyster mushrooms are delicious and good for you. You can buy them from the store, but it's easier than you think to grow them yourself. Home-grown oyster mushrooms are fresher and tastier than store-bought mushrooms, and you know exactly how they were grown from start to finish.
Oyster mushrooms are very aggressive growers. They will grow on almost any wood-like material including straw, cardboard, sawdust, corn cobs, newspaper, and even rolls of toilet paper. You can choose a substrate based on what is easy for you to obtain, but for the purpose of this guide, we will discuss growing oyster mushrooms on straw.
Straw is easy to work with and readily available at farm supply stores. To prepare the straw to be used as a substrate, it must be pasteurized. Cut the straw into 2-3 inch lengths using a shredder or a weed whacker in a garbage can. Scissors are not recommended for this process, because it will take a much longer time to shred your straw.
Once the straw is shredded, put it into a pillowcase and place the pillowcase into a pot of water on your stove. The straw must be fully submerged in the water, so use a weight to prevent the straw from floating to the top during pasteurization. Place a digital probe thermometer into the pot, and keep the temperature between 160 and 170 degrees Fahrenheit for 1 hour. If the temperature goes higher or lower by a few degrees, it's ok - under-pasteurization is better than over-pasteurization. Over-pasteurization can increase the risk of contamination.
After an hour, remove the pillowcase from the water and allow it to drain and cool. You can drain it in your sink, but the best way to drain your straw is to tie the pillowcase up outside and allow it to hang until cool. After the straw is cool, you're ready to inoculate it with spawn.
During the inoculation process, you will fill your spawn bags with the substrate in layers with the spawn. Place a handful of straw into a spawn bag and flatten it a little to form a bottom layer. Do not compress the straw too much, as this will prevent air exchange and increase the chance of contamination. On top of this layer, place a layer of spawn. Repeat this process until the bag is filled about halfway. Fold over the top of the bag and clip it shut or tie the bag with a twist-tie.
Next, it's time for the spawn run.
Place the bag into a cool, dark area. The temperature can fluctuate but should remain at around 75 degrees Fahrenheit for optimal mycelial growth. The spawn run lasts anywhere between 1 and 3 weeks. When the mycelium has colonized the substrate, and it is ready to fruit, you will begin to see small nodes of mushrooms called primordia. Primordia formation is known as pinning, and primordia are the beginnings of the fruits you will harvest.
Fruiting is the final step before harvesting your mushrooms.
To initiate fruiting, the substrate must experience fruiting conditions. Fruiting mushrooms requires fresh air, moisture, and light. At this point in the process, you can take the block out of the dark area and expose it to light. Placing it on a shelf with indirect light is sufficient. The bag must be opened and fanned several times a day. It's a good idea to mist daily, but do not drown the block with water or fruiting will stop.
Mushrooms grow quickly, and within a week you may begin to see small fruits called primordia. Every day they will get bigger, and sometimes from hour to hour, you can see their progress. The journey from primordia to full size can take anywhere from 3-7 days depending on the quality of fruiting conditions, including the amount of air and humidity.
Once the fruits are mature, the edges will curl out, and the gills will be exposed. After you see this, they are ready to harvest. You can either cut off the fruits at the base or grab and twist until they break off. Place the fruits into a cardboard box lined with paper towels in the fridge for storage.
As you can see, it isn't very difficult to grow your own oyster mushrooms at home. The concepts that you learn while growing oyster mushrooms can be applied to other species, with some tweaks here and there. Not all mushroom species use the same methods, substrate, or spawn, but they are all similar enough that learning to grow one species will give you the tools and skills needed to pick up another one much easier.