I once had APE aborts. I bought 2 grams and within 2 minutes, while I was still eating them, I began to feel it. I only ate about 1.5 grams and it broke my brain. It was not my first time with psilocybin but it was my last. I'm afraid of it now.
All that to say it does not take half an hour in all cases.
They were dried. I estimate there were about 30 tiny mushrooms in that 2 grams. I ate about 20 of them.
I have read that an abort contains the same amount of psilocybin as a full grown mushroom. If so, I overdid it by 18 mushrooms.
I knew they would be potent but didn't think they would be that strong.