mushrooms

soak grain in water for 12-24 hours; it will triple in size

simmer grains for about 15 minutes to soften them; don't bring to boil

drain grains such that they're surface dry

fill jars no more than 2/3 full

put the lid on and cover with tin foil

• alternatively you can layer two pieces of foil instead of using a lid 

• the bottom layer perforated to release steam and the top layer intact to preserve sterility

put in pressure cooker and cook at pressure for 90 minutes