White sugar is an item that stores very well for long periods of time and is great for making comfort foods when you need them. I store pure cane sugar because that is what we already typically use.
Most white sugars have a best use-by date of about 2 years. After 2 years of being stored in the original packaging, the white sugar may start to clump a bit but it is still just as good to use. If you store your white sugar with optimal storage methods, it will put off clumping much longer. As I mention before sugar that has clumped together is still good to use, its just a pain to break apart.
Optimal methods of storing white sugar should address 3 things: protection from moisture, protection from light, and avoid high temperatures. Probably the most important of these 3 is to keep your white sugar protected from moisture exposure. I have also been told by multiple people not to use oxygen absorbers with storing white sugar, it will cause it to clump faster. Most sources say that white sugar will store almost indefinitely under good storing conditions.
I purchase white sugar in bulk bags and pour them into a 5 gallon food-grade bucket with a Gamma Lid for easy access. This seems to keep the moisture and sunlight out very well. My basement storage room, where I keep my sugar, stays cool enough for almost everything I store. I try to keep 2-3 buckets full of white sugar in our food storage, which is well over a 2 year supply of sugar for our family. I have heard of people keeping sugar for over 5 years this way without having any clumping issues.
I have a 45 gallon plastic garbage can with a loose lid that I filled with white sugar about 7 years ago. The sugar is now so clumped together that it is a workout to scrape it out. From this, I can tell you that a non-sealed container is a good idea for long term sugar storage. The sugar still tastes great but I just can’t stand scraping it out every time I get into it. I haven’t decided what to do with what is left in the garbage can yet but I have started to use my sugar from the 5 gallon buckets instead, for now.
To build up to the amount of white sugar I have in my food storage, I bought a 10 pound bag of sugar every month. One 10 pound bag of white sugar usually lasts our family about 3 months. It took us about 20 months to build our supply of three 5 gallon buckets full. For rotation, we now wait until one of our three 5 gallon buckets is empty and then we start buying one 10 pound bag of sugar every month again, until that bucket is back to full.
I have been told that powdered sugar stores really well also but we don’t use powdered sugar very much. I just keep 1 bag of powdered sugar in my pantry at all times.