Venison liver will spoil much quicker than regular red meat. In the field, I often cook my livers in camp rather than trying to keep them fresh and packing them back home. I simply slice the liver in quarter-inch slices and then brown it with sliced onion in whatever’s handy: oil, butter, bacon grease. It’s as good as it is easy. I prefer liver on the medium-rare side. However, the less you like liver the more you want to cook it. Cook it long enough, and it’ll start to taste a little like jerky. Whatever you do, don’t waste it. Even if you don’t like liver, learn to eat it. If you respect the deer, the wild will respect you in return.