I do not know what you mean by winterize the BHO.
1. I grind an Oz
2. I freeze Oz
3. I pack into stainless steel extraction tube
4. I attach vacuum pump and run for 5-10 min.
5. I blast with 2 cans of Butane. Best butane to be found. 5x refined or more and 11x filtered or more
6. After around...