How to Grow Mushrooms: Setting up a Lab

To accommodate the grow room expansion, we built a new lab several months ago. While the differences between it and our old lab are all pretty small in themselves, together they create a substantial improvement over the old layout. We thought we’d share our set up and what we have going on.

• We use positive pressure, clean air coming in through the main filter and pushing the old air out, the pressure actually pushes against the door, causing it to resist being opened.
• We use a three-stage filtration process. Air comes through a dust filter on the outside wall, then through an allergen pre-filter above the squirrel cage fan that pushes the air through the HEPA filter and into the lab. This allows us to catch most large particles in the cheap filters upstream, and prolong the lives of the progressively more expensive filters downstream.
• To make sure the pre-filters aren’t clogged, we do a lighter test. This is simply holding a lit lighter and gradually bringing it closer to the filter. At working distance, the flame should be blowing about horizontal, but not blowing out. Once it gets closer to the filter, the airflow might even blow it out. If the flame blows out at working distance the airflow is likely too strong and could dry out your materials, but if it’s not pushing it horizontal the pre-filters should be replaced.
• To test the HEPA filter to ensure we’re getting proper sterility, we place an agar dish without any cultures in it in front of the filter for an hour. Then we seal it and let it grow for a few days. If contaminants show up, we know it’s time to replace the filter.
• We have a cardboard flap above the filter that enables us to control how much air is being recirculated within the lab by restricting or allowing inside air into the main inlet to the filter.
• Occasionally, we use compressed air Duster to clean the bottom edge of the HEPA filter where dust has a tendency to collect. We used to use a small brush, but try to avoid physical contact to keep contamination risks low.
• The lab table was repainted and coated with acrylic, which we found out isn’t actually the best idea. Turns out Acrylic and isopropyl alcohol don’t mix too well…
• We installed warm light LED panels above the lab table to increase visibility.
• We’ve found plastic shelves to be difficult to clean, and it’s hard to find any with desirable dimensions. We prefer our custom designed wood shelves treated with waterproof, acrylic paint.
• We have a fridge in our lab for long term storage and to slow down spawn we may want to hold on to longer.
• It’s important to make your workspace a place you enjoy being. Andrew has a sound system set up so he can listen to music while working, which makes it much more enjoyable and helps him get more done.
• Keeping a notepad nearby to track your production is a good idea.