A mushroom growing kit has many components—substrates, incubators, harvesting knives—but you’ll need to choose which spores you want to grow before you start. How do you extract spores from mushrooms? Existing mushrooms can give you what you need to begin the growing process. Here's how to harvest spores cleanly, step by step.
Choose Your Species
What kind of mushroom do you want to grow? You can harvest spores from mushrooms you purchased at the store, from small button mushrooms to large portobellos. Make sure you know exactly what species of mushroom you’re working with. A specimen you found in your backyard may be of unknown origin and could be inedible. Choose a specimen that’s grown to full maturity — our guide to harvest timing by species helps you spot a mature cap.
Keep It Hygienic
Hygiene matters at every stage, but it's especially important when you're collecting spores to propagate. Wipe down all surfaces, use clean paper for your print, clean every tool, and wash your hands thoroughly (gloves and a mask are even better). You'd be surprised how much contamination of spore prints comes down to skin, breath, and dust. Working inside a still air box or in front of a flow hood helps a lot.
Make a Spore Print
This step feels a little like a craft project. To start, you’ll need a piece of white paper, a piece of black paper, and a glass bowl or container.
Place the white and black papers side by side. This step will ensure you collect all the spores you can. Some are light in color, and others are darker; you’ll be able to see the spores better with the additional contrast.
Snip off the stem of your mushroom with a clean, sharp harvesting knife or scissors. Add a drop or two of water to the mushroom cap before placing it, gill side down, on the paper (one half on white, the other half on black). Cover the cap with the glass bowl or container to keep extra airflow from disturbing the process.
Let it sit for 24 hours to allow the spores to do their work. When your waiting period is up, carefully remove the glass container and lift up the mushroom cap. You’ll see the print it made on those papers—that print is made up of your precious spores! Not sure which part is which? See our guide to mushroom anatomy.
Collection and Storage
To keep your spores safe, carefully fold your spore print and store it in a sealed plastic bag in a cool, dark place. The fridge is ideal: cold temperatures slow the growth of any bacteria or mold that sneaked in, so prints and syringes stay usable for months. Next time you want to inoculate your substrate, you can scrape them gently off the paper and introduce them to a spore syringe.
Spore syringes are among the many mushroom cultivation supplies offered at Midwest Grow Kits, and they are the ideal way to keep spores safe and ready for use. Carefully introduce the spores from your print to 10 mL of lukewarm, sterilized water. Pull that liquid up into the syringe. (Doing this inside a sealed bag will help prevent contamination from the air.) A swab method also works, but syringes are more precise.
Spore syringes can be stored in your fridge for up to six months. Keep them safe in a sealed bag. If you want faster, more predictable colonization than spores give you, read liquid culture vs spore syringes, and if you're buying rather than making your own, our spore syringe buying guide covers what to look for in a vendor.
Getting started with your own mushroom growing adventure takes a few extra steps, but they’re worth it in the end. Midwest Grow Kits provides the best supplies to help you extract spores from mushrooms and get them ready for inoculation.