How to Grow Oyster Mushrooms at Home

Five years ago, when I completed an intensive mushroom growing course with Peter McCoy, I had a fantasy to become a mushroom farmer. Little did I know, a pandemic and shelter-in place protocols would lead me to explore this dream in a totally different way.

I had been growing mushrooms on and off ever since that course, and after a successful harvest, a couple of friends asked if I could make them a mushroom growing kit. I said “yes!” At the time, there was a big trend in starting gardens and growing your own food during the shelter-in-place orders. After a Facebook post to friends, a couple of mushroom growing kit requests, turned into 80 orders overnight and I had unwittingly started a mushroom growing business called Mushrooms from Mars.

I learned a lot about how to grow oyster mushrooms at a home scale and how to scale up. My main aim for Mushrooms from Mars was to inspire people to build a relationship with their food by growing it. This is why I am happy to be a resource and share my easy how-to techniques with you.

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Mushrooms From Mars stackable growing pods.

Before growing your own mushrooms at home, I recommend learning about the mushroom life-cycle. Understanding the basics has helped me be successful at growing mushrooms. Here are the steps that have been 100% successful for me for growing my own oyster mushrooms.

  1. Gather materials

It’s important to gather all the materials you will need before you start. When we collaborate with living systems we are on their time. Make sure to have straw, a 5-gallon bucket with drilled holes, and fresh myceliated grain spawn. You can use a regular plastic five gallon bucket with a good lid and drill ¼–½ inch holes in the bucket spaced about 5 inches apart. You can get the grain spawn either from a local mushroom company or by ordering from Aloha Medicinals.

  1. Prepare the substrate
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The substrate is the material that the fungus consumes. For oyster mushrooms, I use straw as my substrate. Fungus needs to have a head start on colonizing a substrate for successful fruiting. This is why we sterilize or ferment the substrate; it sets the mycelium up for success. I prepare the substrate using a cold pasteurization method. To do this, simply submerge straw under water for 5–7 days.

  1. Inoculation

Once the straw substrate has completed cold pasteurization, it’s ready to be inoculated. Clean the working surfaces and bucket by spraying the surfaces with rubbing alcohol or a bleach solution. Remove the straw from the water and let it drain. Before stuffing it into the bucket, see if the straw has a trail of drips. If it does, it is too wet and needs more time to drain. While stuffing the bucket with straw, sprinkle myceliated grain spawn throughout. A higher inoculation rate has a higher success rate. I recommend 4 cups of grain spawn for a 5-gallon bucket or 2 cups of grain spawn for a 2-gallon bucket. Stuff the bucket as much as possible. It is good to not have much space between the pieces of straw. I like to sprinkle some grain spawn on the top, and then put then close the bucket. Additionally, there are many types of nutrient additives you can add to your bucket. I like to sprinkle in ½ cup -1 cup of fresh day-old coffee grounds to boost nitrogen and acidity levels.

A note about contamination- It’s best to clear all your tools, surfaces, buckets, etc, and then leave them exposed to the air as little as possible between cleaning and inoculation, as there are spores of all sorts of contaminants all around us. On a small scale, you generally have high success rates with Oysters, but still, even higher success rates will be achieved in clean areas with very little airflow. Once the bucket is closed, resist the urge to take the lid off (at least too many times) because each time you do can be an opportunity for contamination.

  1. Colonizing Phase

After inoculating the bucket, choose a cool, dark place to store the bucket. It is important that the bucket does not receive direct sunlight and is protected from wind. This is the waiting period. During this phase, the mycelium is growing and expanding, covering every crevice of straw, and decomposing it. Once the mycelium has filled up the whole bucket, it has successfully colonized the substrate.

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The mycelium network colonizing the straw substrate.
  1. Fruiting Phase
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Oyster primordia formations.

When the mycelium is healthy, vigorous, and has fully colonized the substrate, white mycelium may appear in the holes of the bucket. Eventually, the mycelium will begin to form primordia, which will poke out of the holes. The primordia sometimes look like bumpy, outy belly buttons.

During the fruiting phase is it important to make the environment outside of the bucket more humid. I do this by wetting the ground and putting a tarp loosely over the bucket. Every morning, add water to the ground and throughout the day the evaporated water gets trapped under the tarp. During the fruiting phase, it is important to check on the mushrooms often because they may need more water and mushrooms grow fast and could double in size in one day.

  1. Harvest and Storage

Oyster mushrooms can become bigger than my hand and often grow in clumps. The clump is ready to harvest when one mushroom cap in the clump begins to turn from concave to convex or the cap becomes so big that it begins to tear. Harvest the clump by either tearing it off or cutting it off with a knife. Mushrooms can be stored in a paper bag in the refrigerator for about a week if they are not used right away. (Plastic bags tend to make the mushrooms slimy.)

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This pink oyster mushroom is larger than the palm of my hand!
  1. Culinary Dishes

There are endless recipes that include mushrooms. Add them to a stir fry or a pasta dish! I really love keeping it simple to savor the flavor. I tear my mushrooms into pieces and then dry fry them with a little salt. After they have sizzled in the pan, I turn off the heat and add a small amount of butter and garlic powder. These can be served as an appetizer or compliment another dish.

I wish you wild and wonderful mushroom adventures!

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