How to preserve fat or I need my bacon...
Bacon was the primary way that country folk had grease to add to meals for cooking and for adding flavor and salt into their meals. This means you need to be able to cure pork and other mammals. One can't ever cure poultry, it's not possible to do it safely.
Here's a link which describes how to harvest nitrates from Instant Cold Packs. Now, honestly nitrates are good for you, but it will ensure a good cure of the meat, and you're trying to avoid spoilage. Most people won't know how to do this, so this gives you a trade item to harvest many months after a collapse when a few of us might still be around. Otherwise if it's not that bad a collapse, most people won't know the value of them, and you can trade for them. It certainly is possible to buy “cure” from suppliers today.
This is the best way to save that animal fat versus having to cut it out for making jerky or canning it.
[link to www.survivalblog.com
Making bacon with pickling salt and smoking it:
Making bacon with maple cure:
If you've ever had a country ham, you know that a mold can develop on the outer rind, but you merely cut it off. For those who've never had a cured ham, it's very salty, so you adjust your cooking to deal with the intensity.