How I make mushroom fruiting blocks for hardwood loving fungi (5lb block)

I mix my substrate inside the bag as I've found it's the easiest way.

my recipe is -

800g hardwood fuel pellets
160g organic bran (50/50 oat and wheat bran)
35 grams Gypsum (optional)
1250ml of filtered water

Pressure cook for 2:15 min (135 minutes) and let cool inside the pressure cooker for 12 hours or overnight.

I have been using the instant pot as my pressure cooker with 100% success. I use the pressure cook preset on the high & more setting.