I have a Oatmeal Stout recipe that calls for 4 tsp/ 1 gram of Irish moss powder. The LHBS had Irish moss, but I wouldn't call it a powder. They're small flat pieces maybe the size of half a grain of rice. Should I pulverize it in a morter and pestle? I would assume this would make it more efficient. Or just measure out a 1 gram and not worry.
If I use my (near impossible to sterilize) morter and pestle, is there any concern that the irish moss would not be sterile? Its going in the last 10 minutes of the boil.