Great idea, Susan,

I'd like to add a couple of thoughts to that, having learned a few lessons on doing this from my friend's father.

If you're going to do this, only use interior non-insulated walls. You don't want to lessen the house's efficiency, and you don't want your goods exposed to constant fluctuation of outside temperature, especially in extreme parts of the seasons.

As Susan mentioned, stack cans by date vertically instead of horizontally, keeping similarly dated items in a column rather than a row. This will keep you from having to constantly go to the bottom of a stack for items that will expire sooner.

Try to keep the same items in the same column as much as possible. That way, should you want a can of corn for instance, you don't have to unstack a column of pinto beans to get to it, only to have to restack the beans when you've gotten what you wanted. This will also help when it comes time to resupply because visually it's easy to keep track of.

You can easily make shelves between the wall studs to save some of the hassle that will come no matter how hard you tried to stick to the two ideas above. Most studs are 16" apart from center.

Be careful while stacking and removing cans. While it may not matter that one side of the wall has a hole in it that you're utilizing, a hole in the other side of the wall might be an eyesore in the living room.

As badly as most houses are regarding transferring noises from one room to the next, you're making it worse by removing the materials between rooms. In other words, don't stack food in the walls behind your bed if you and your SO tend to make a lot of noise in the sack.

If this is to be a hidden cache, hide the items well, but don't make them so hard to get to that you don't rotate your stock consistently. Behind the hutch behind paneling screwed into the wall studs is a great hiding place, but it's a pain in the backside to get to.

Remember where your caches are. I learned that my friend's father learned about storing items in the walls from his father after my bud's grandfather died. While helping to fix up the house for sale, we found a 20 year old canned ham and several cans of SPAM behind a piece of sheet-rock in the master bedroom's closet. We were toying with the idea of letting some future resident find the potted meats, but decided not for reasons of health.