picked up two slabs of spare ribs at walmart and I tried to get the membrane off, but could not do it. This is the first time this has happened to me. I usually use a fork at one end to loosen it up and take a papertowel to grab the membrane and it usually comes off nice and easy. I ended up just taking a fork and lightly scrapping the membrane off each rib. Will the membrane cookoff over the next several hours?