Making BRF cakes for the first time

Was wondering if anyone has some insight into this. I am going to be making BRF cakes for the first time and picked up a big ass pressure cooker for cheap at a resale shop. When I sterilize the BRF cake in the jar, how tight does the lid to the canning jar need to be. Ive read that it needs to be tight and it needs to be loose. Just looking for someone with a little more Myco experience than I do to give some insight. Picked up some spores from spores101 and dont wanna screw this up. Thanks in advance!

You put holes in the lids for inoculation so how tight the jar lid is doesn't matter. Go to youtube and search let's grow mushrooms and watch it as many times as needed until you have a feel for the basics. Good luck.

well if its loose when you put it in the pressure cooker water could get into it..i always tighten my lids all the way.

My advice? don't make BRF cakes at all. It is in my opinion the worst way to grow mushrooms.