Yes, much much quicker in coffee grounds (and other similar media such as straw and sawdust) than in logs. Logs have the benefit of being very low maintenance and not needing buggering about with pasteurisation or sterilisation, (and dispense with the eyesore of plastic buckets and what have you) but are very much a long-haul kind of deal. Not had much luck with logs but haven’t given them a great deal of effort.
Pasteurisation is better than sterilisation for oysters because you don’t have to be nearly so careful / use pressure cookers and filter bags etc. Oysters are vigorous enough to outcompete moulds and stuff on pasteurised media, other species not so much. Really can’t beat a fresh homegrown oyster fried up in butter though, proper meaty stuff, batters the shit out of anemic shop-bought fungi. Coffee grounds are automatically pasteurised by the brewing process, I used to whack them straight in a ziplock bag in the freezer until I’d saved enough to do a bucket of oysters.
I also tried mixing in some straw from a pet shop that I pasteurised in a crock pot and that worked even better. I’d echo that it is a lot easier in colder weather though, as soon as things warmed up I had a lot more trouble with attracting insects and you have to start looking at nets and stuff.
