I tried a lot of things regarding food preservation in a natural environment, from hanging it on a tree to burying it in the snow. Lastly, I found URSACK to be the most convenient way to deal with that problem.
When you go for a multi days trip over an area with a high probability to cross the path of bears, wolves, coyotes, lynxes, cougars, raccoons, squirrels and all sort of mice it becomes crucial to keep your food out of them otherwise you end up loosing some weight :-).
First time out with the new bag and a raccoon tried to empty it! It partially accessed the content because I did not tied enough the bag but it was so noisy that it woke me up by night and I was able to chase the intruder. There was obviously failed attempts to open it by teeth, it was only able to put its arms by the gap I left in the opening. Luckily, I put the trash at the top of the food bag so even if it was painful to collect pieces of plastic by night with all mosquitoes around, we kept our food almost intact for the rest of the trip. Yay!