Can I store suet or home-rendered tallow at room temperature for a year?

YouTube shows many ways to can tallow, including heating the empty canning jars in an oven to 250 + degrees and then pouring the hot (250+) tallow into the jars and sealing them with clean lids.

They seal nicely, the same as any canning process, and will last indefinitely on the shelf. I have used this method to can all sorts of fats, easily storing them for 10 years or better. As long as the seal remains on the jars, what's inside will remain safe and usable. Don't worry about glass breakage; it doesn't happen. 250 degrees is the temp a pressure cooker produces at 15 pounds pressure, except by preheating the jars in the oven you are able sanitize them and also keep them dry... also you won't shock the glass when you pour in the hot fat.

When the hot fat cools a vacuum will form in the jar and the lid will seal. Just be careful and wear gloves, because you are working with very hot materials.

Suet was used for pemmican 100s of years ago, I read in history books they found some that had sat dry in bags for over 25 years and was still good Native Americans used this process for hundreds of years , Lewis and clark used Suet pemmican for a major food source for months on their long trip over years

I render mine in a slow cooker then filter and pour into Silicone cupcake pan making small discs. I then put these in plastic freezer bags and store them in the freezer. They will pretty much last forever in there so long as I double bag it to keep the freezer burn down and since they are easy size I can just grab one when needed. In theory you can store it in jars but the problem can happen with impurities spoiling a jar. I tend to salt the bottom of the jar and warm can them. For extra security you can use a food grade wax at the top of the jar before sealing. I would expect this to be good for at least a year in jars if not more. Note that suet is going to keep much better then lard. The fat around kidneys was used for candle making and keeps solid at room temp so less air to spoil.

the best way to keep it is by vacuum sealing the fat or tallow making sure it is absolutely clean and dry. It will keep that way in a cool and dark place for well over a year.

I waterbath can my tallow in jars for 10 minutes. I found a really good scientific explanation once saying why it was ok to can it this way but I can't find it now. Basically for fat to go rancid or for bacterial / mold to grow there has to be certain conditions met such as moisture, air, etc. Because rendered fat has no moisture, if done correctly, then it is safe to can in a water bath. Then you can store it on the shelf for longer than a year and it takes it out of the refrigerator or freezer. Seems I'm a little posting to this now but this is knowledge for the future :D

Pure fats tend to last quite a long time and for whatever reason bacteria and bugs are not attracted to pure fats. You can also preserve food with ghee, lard and tallow as it's an oxygen barrier.

Tallow does not need to be refrigerated and can last a year or longer. I would not worry greatly about decomposition, but oxidation can be a problem. Make sure to store it in an airtight container and you shouldn't have a problem.