There are many foods that people keep in the fridge that don’t need refrigeration, keeping them cool does allow those foods to last longer, but they don’t NEED refrigeration. We have a small cube (dorm sized) refrigerator but rarely turn it on. We do have access to a neighbor’s refrigerator if we really need it (for milk mainly, and the occasional pound of ground beef), I will say that walking/hiking up and down the mountain side to get a glass of milk makes one not be as interested in having milk.
Anything that contains vinegar is fairly safe to keep outside the refrigerator, pickles, pickle relish, ketchup… I don’t know about mustard (I don’t eat that very often). I know mayo does require refrigeration. We get fresh eggs from a friend and I request that they not be washed, they can safely stay outside the fridge, We use a lot of powdered and canned milk for cooking.
One thing I do is I purchase those little individual serving size packets of mayo, mustard, ketchup and pickle relish, these do not need refrigeration, but it does say on the box to keep them in a cool location. I find that the mayo has to be used within a year of purchase or they start tasting “off”, the rest of them seem to last a lot longer, I suspect it’s because they have lots more vinegar. You can find these by the box in Sam’s Club, you can also order them from the internet.
In the 3 years we have lived off grid, we have learned how to live with very little refrigeration for our food, I just don’t buy very many food items that require it.
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