We have Chronic Wasting Disease here so it's not a good idea to use brains for tanning. Doesn't matter though, lecithin is the active ingredient in brains. I buy mine in a little tub, it comes in yellow granules. You just dissolve them in warm water until no more granules will dissolve, then use it just like you would brains. I've been doing it this way for about 20 years. Works great.