Sounds like it may be a bit underpowered. I don't waste my good bud on butter, I just use shake and trimmings but will usually use 20-30 grams per quarter pound of butter, usually actually using about a stick and a quarter to compensate for some loss. Being that you're using bud it may very well be OK, but only 10-12 grams for a whole pound sounds like it will be a bit on the weak side. Use more bud or less butter is my recommendation.