16 December 2023
Written by Benedict Vanheems
Mushrooms are one of the most exciting and rewarding things you can grow at home. Not only are they quick and easy, but they are also delicious. While mushroom-growing kits are an option, they can be expensive and sometimes unreliable. Fortunately, there’s a simple, cost-effective way to grow mushrooms from scratch. In just 30 days, you can harvest fresh, homegrown blue oyster mushrooms without breaking the bank.
Mushroom Growing Equipment
For this project, you’ll need a few basic items:
- Plastic Buckets: I use one-gallon (5-liter) lidded plastic buckets as containers. They are inexpensive, and you can often get them for free by asking local restaurants for used containers. You can also opt for mushroom-growing bags, but using buckets allows you to reuse them multiple times.
- Straw: This is the substrate your mushrooms will grow on. Straw is cheap and easy to find. You can purchase it from pet stores, which often sell it in small, pre-cut pieces, or use a larger straw bale if needed.
- Mushroom Spawn: I use grain spawn because it’s easy to handle. Blue oyster mushrooms are ideal for beginners, as they are hardy and highly productive.
- Surgical Tape & Pillowcase: You’ll need surgical tape to cover the holes in your bucket and a pillowcase or net bag to pasteurize the straw.
Preparing Your Mushroom Buckets
Start by drilling holes in the sides of your bucket. The holes should be about 10-12mm wide, with a first row positioned near the top of the bucket and a second row two-thirds of the way down. Make sure the holes are staggered. Drill a few smaller holes at the bottom for drainage. These holes allow for air exchange and provide space for the mushrooms to grow.
If you want to scale up, you can use a larger, five-gallon bucket with up to four rows of holes.
Pasteurizing the Straw
Pasteurizing the straw is an essential step to eliminate harmful microorganisms while preserving beneficial bacteria that will help the mushrooms grow. Place the straw in a pillowcase or net bag, then immerse it in water heated to between 140-175ºF (60-80ºC) for one hour. Be sure to avoid boiling water, as it will destroy helpful bacteria. After the pasteurizing process, let the straw cool and drain until it’s just damp and heavy.
Inoculating the Buckets
Once your straw is ready, it’s time to add the mushroom spawn. Before starting, sterilize your hands and equipment with isopropyl alcohol or a suitable sterilizer to avoid contamination. Massage your grain spawn to separate the grains before opening the bag.
Layer the pasteurized straw and grain spawn inside the bucket, starting with a handful of straw, followed by a handful of spawn. Repeat the process until the bucket is full, aiming for about 90-95% straw and 5-10% spawn. Once the bucket is packed, seal it with the lid and cover the holes with surgical tape to keep moisture in and air flowing.
Place the bucket in a location with a stable temperature, and over the next few weeks, the mycelium (the mushroom’s root system) will begin to colonize the straw.
Growing Mushrooms
After two to three weeks, you should notice the straw turning white as the mycelium spreads. At this stage, small “pins” (embryonic mushrooms) will begin to form at the holes in the bucket. These mushrooms will grow rapidly, often doubling in size each day.
To ensure healthy growth, keep the mushrooms in indirect light and high humidity. Mist the mushrooms regularly to maintain humidity, especially in the morning and evening.
Harvesting Your Mushrooms
Your mushrooms will be ready to harvest when the caps have opened, but before they flatten out completely. To harvest, twist and pull the mushrooms gently from the cluster. You can expect multiple “flushes” (or rounds) of mushrooms, with a second and possibly third crop emerging within a few weeks.
When the first batch is finished, you can use the mycelium-laden straw to inoculate a new batch of pasteurized straw. This allows you to continue the cycle and grow more mushrooms from the same spawn.
By following these simple steps, you’ll be able to grow your own delicious blue oyster mushrooms in just 30 days. With minimal investment and effort, you can enjoy fresh, homegrown mushrooms year-round.