I've been putting dry bulk foods into used Coke bottles for storage. The place where I'm staying for another week now has bottles of soybeans, polenta, flaxseeds, whole wheat flour, white flour, rice, and lentils. This makes me happy. I feel like I'm creating order out of chaos. The bottles look a lot prettier than half-full bags of lentils, and they also exclude cockroaches and beetles better. (Sometimes beetles can get into even sealed-shut plastic bags.) They also seal hermetically, preventing oxygen and moisture from the air from attacking the contents, and for foods that come in paper bags rather than plastic, there's the additional advantage that they protect the food from possible roof leakage --- not a merely theoretical advantage in the places where I've been living!
One of the bottles I have to work with is not a Coke bottle, but a bottle for Terma, a sort of bittersweet herbal infusion that's popular here. The plastic is green, so a lot of foods look horrible inside of it, despite its graceful form, which looks rather like a thigh modified to be rotationally symmetric. So rather than using it for storage, I scissored off the top of the Terma bottle to use it as a funnel for filling the other bottles with, then heated up the neck with a stove flame in order to squish it down a bit so it fits inside other bottle necks --- not actually necessary since it's not a big deal if I spill a few drops of flour or a lentil or two, but helpful.
(Another Terma bottle got used for yerba mate instead, which looks fine when tinted green.)
Washing the bottles out is kind of a pain because they don't dry easily. I've taken to dripping a few drops of 96% ethyl alcohol into them and shaking it around to take up the water. Then I can just pour it out, because it has a lot less surface tension than water. Also, it's reassuring that it's a mild disinfectant.
The more time-consuming step --- which I'm not doing this time around --- is removing the glue that keeps the labels on. Terma labels come off with just water, leaving only a little residue, but Coke and Pepsi label glue (at least currently in Argentina) won't come off even with alcohol; turpentine works, but also penetrates the bottle and can leave the food tasting like turpentine. Filling the bottles with cold water before turpentining the labels off reduces this problem.
A friend suggested freezing foods like flour for a while before storing them, in order to kill any beetles that might be hiding in them, which seems like an eminently sound idea to me. After all, even if the bottles keep the beetles or moths contained, you still lose a bottlefull of food, which could have been avoided if you just had to discard a single beetle.
In order to limit the lifetimes of foods stored this way, I label the bottles with the name of the contents and the date it was bottled. So far I haven't found a good way to do this. Masking tape is workable, but the adhesive decays over time, and two years later when I use the bottle for something else, I'm left with stinky dried adhesive on the outside of the bottle. Also, the masking tape itself is kind of ugly. Permanent marker works, but you can't take it off, and I fear that the solvent will flavor the food. Maybe paper labels with some kind of water-based adhesive, such as wheat paste, would be best, but first I'm going to try tying bows around the necks of the bottles using a wide cloth ribbon I write on.
Many people prefer glass bottles for this kind of thing because they're prettier. Plastic Coke bottles have three advantages over glass bottles: