I have wanted to inoculate coffee grounds with oyster mushrooms for quite awhile. With the help of the cool people at Wild Joe’s, I have managed to collect some great organic, free trade coffee grounds. The grounds are too rich to waste and the folks at Wild Joe’s  feel the same way! Oyster Mushrooms grow on almost anything, so it stands to reason they would like coffee grounds. The very strength of coffee grounds, is also their downfall.They are a perfect semi sterile substrate for growing fungus because they have been steam pasteurized. The problem with that is the quickest fungus to get to them is usually green mold. The trick to this project is going to be controlling the growing conditions to help the oysters while making the mold unhappy.When I first put the spawn in the coffee grounds, the spawn took off because it was warm in the garage and the spawn was hungry. Then I noticed the green mold creeping in, and as you see in the pictures, there is a major war going on between the mold and the oysters.

The little brown specks are the grain from the spawn mixture. The white spider web is the Oyster spawn growing and the green is, you guessed it, mold.At this point the project has gone outside,and neither the spawn nor the mold is happy! But I know the spawn is still growing as the temperature is just above freezing, and the mold won’t survive the cold.Hopefully the bucket will produce mushrooms. Either way the experiment has already told me that Oyster spawn does indeed like coffee grounds.

Thanx again to the awesome crew at Wild Joe’s for saving the grounds for me,and thank you Hannah for setting it up. Stop by their coffee house on Main Street in Bozeman and create some grounds for us.