Winter mushroom project

In the near future we hope to be able to offer fresh mushrooms to farmers market and mushroom CSA customers, in the winter!

This is a very different kind of mushroom growing, and there is much to do yet, but we’re well on our way.  Thanks to the Next Stage Grant offered through the Mill City Farmers Market, we got some help to make this happen.

What we’re trying to do:

  • Grow mushrooms indoors in the winter, within a corner of our packing shed.
  • Grow up to 25 lbs. per week of winter mushrooms on sterilized sawdust, wood chips, or other substrates, since growing them this way is more space efficient.  We should be able to grow shiitake, oyster, lions mane, and reishi this way.
  • Grow mushrooms on mushroom blocks purchased by Field and Forest Products (our mushroom seed supplier), since this will simplify our project significantly.
  • In order to grow, mushrooms need optimal temperature, humidity, and fresh air (CO2).  Here’s how we hope to maintain control of these conditions:
    • temperature – we are insulating the chamber with a walk-in box, and using electric heat to heat it.  We are also preheating fresh air as it comes in (see below).
    • humidity – we are installing water misters to maintain 90% humidity, under pressure and after reverse osmosis treatment.
    • fresh air (CO2) levels – we are using a fan to force preheat fresh air through a pre-conditioning plenum.  Fresh air is necessary to maintain the quality of mushrooms.

We’ve made some progress, as you can see below, but there is still much to do.  Stay tuned for more updates on this project!

fruiting chamber feb 2019

large pipe is fresh air intake small pipes will provide water to misters

chamber interior drainage

drainage channel – interior of fruiting chamber

chamber drainage and sink

exterior of fruiting chamber – including drain pipe for chamber and hand washing sink

preconditioning plenum1

preconditioning plenum – insulated chamber to pre-heat fresh air

preconditioning plenum2

interior of pre-conditioning plenum. Duct fan blows air into plenum ducts, and into pipe leading to fruiting chamber