I thought it was because it bubbled in one of the bags at some point. Anyone else have a vote?
I thought it was because you are trying to get all the little (THC) bubbles. I have seen it done and with the bags they only strain. You just add ice and use a food mixer, the ice helps the plant material seperate allowing the THC balls to fall through screens. Then as you remove each one you will be left with some material that did not fall through, then the one before you final one will have the best. Reason is the one before the last catches the most non broken THC balls, allowing for great potancy.