Fungal eruption

It was just over a month ago that we took away from the mushroom growing course our tubs of tightly-packed layers of straw, coffee grounds and fungal spawn to await the development of fruiting bodies from the new mycelium. One of my son's tubs (packed by me he says) has already started to fulfill its promise, he showed me today.

My tubs have produced nothing more than mycelium. That may be to do with the fact that I put them in a cold greenhouse while he left his in a well-used steamy bathroom. I've moved mine now and shall await developments.  
Although whatever erupts is never going to match this wild oyster mushroom jackpot in 2011.