After reading everything in this thread I'd even recommend drying the flax in an oven before infusing it. Might be overkill, but unless it is stored under dry conditions it might absorb a considerable amount of water. I have some cotton flox in a small glass jar, someone left it open for an unknown duration and it started to become clumpy. The flox in the original plastic bucket it came in is still dry after several years.

Well I did have it under vacuum for 12 hours before infusing in an attempt to boil off moisture. Got careless after that.