The jars are colonising, but we've got contam!

Published on Nov 1, 2021

After two weeks of incubation in a dark space, I figured the jars would never colonise. I inoculated them with pink oyster and expected some mycelium growth after about 14 days.

In a way, I gave up, but I kept them, just in case I was wrong and they are just taking their sweet time.

The two jars took about four weeks to start showing mycelium growth and only after I let a bit of air in them. I unscrewed the tops slightly. That seemed to have done the trick, however I am not 100% sure if it was indeed the air that gave them a jumpstart.

Fluffy pink oyster mycelium in a jar
I don't think those pink patches are mould

Sadly, one of the other pink oyster mycelium (using brown rice flour and vermiculite substrate) got contaminated somehow. I noticed black blotches on the side of the tub and I became worried that it is black mould, which is threatening to a person's health. KILL IT WITH FIRE.

a black mouldy patch growing in mushroom mycelium
Is that... black mould?!
a close up showing mould growing in a mushroom mycelium block
Ugh, seriously

I grabbed the tub, went outside and opened it in the sunshine. The mould was thankfully not black, but rather a dark green. I did some searching online and it seems to be an asexually reproducing fungi called Trichoderma, a rather common type of mould with antibiotic properties.

Green mould overtaking oyster mushroom mycelium
Fluffy green penicillin killing my oysters

In the sun I was able to have a better look at what was going on inside the tub. It was more than I noticed. Sadly, I had to dispose of this one, as I am unsure of how to deal with this type of infestation of competing organism at this stage.

A lesson to myself is to work cleaner, I really need to pay attention to everything I touch and do to avoid this.