I have always rinsed my meat before grinding if I see hair on it. Usually only a few pieces will have some hair on it. It has never affected my grind, though I do have a heavy duty LEM so that may help. I do like to place the auger and plates in the freezer to cool them down before I start grinding and only pull out the meat from the fridge as I need it rather than letting a tub of meat sit while I am grinding and letting it get to room temp.