I know, I know. Yes, if it hangs with the wrong crowd at an early age, and doesn’t have positive adult role models. 
I don’t frequently use sugar (what, me bake?). I have sugar in a plastic canister that has got to be two-plus years old.
It isn’t bricking up or anything. There’s no moisture in there, so it’s still quite granular. No invasion from insects or anything.
So, does sugar ever go stale, or some-such? When? What happens?
Sugar doesn’t go bad, since it’s a preservative (think jelly – all you need is a little parafin and it’s safe for years). As long as it’s kept dry, mold won’t attack it.
Refined sugar is a simple chemical compound and unless something is added (water, for instance) it doesn’t break down any more than salt does.
I read somewhere that the relative humidity level in sugar is less than 0.5%. Perhaps this is why sugar “never goes bad.”
Not to hijack, but here’s my question: Why is the RH level in sugar less than 0.5%?
I would imagine that if it got much higher than that, it would cease being sugar crystals, and become sugar water.
Sugar has even been used to treat infected wounds; the osmotic gradient causes the bacteria to literally shrivel up, I would imagine the same thing makes it quite difficult for bacteria to spoil it in storage.
er…or my cuts.
http://www.slackinc.com/general/idn/199702/sugar.htm - not for you if you get queasy at the thought of large open wounds, clean or not.
I saw something on discovery (?) recently regarding Hammurabi’s code and early medical practices that said they smeared honey on open wounds as an antibacterial agent.
http://www.islamset.com/sc/honey/shawki.html - apparantly, people are still fiddling with the idea.
Meg
They’ve recovered honey from Egyptian tombs, 3000 years old, and still good. (But severely crystallized, I bet.) The stuff is so hygroscopic (I just love an opportunity to use the word “hygroscopic”!) that it just sucks all the moisture away from bacteria depriving them of life.
**
Substitute “she” for “it;” “joy” for “moisture;” “Milo” for “bacteria;” and “him” for “them;” and Jomo Mojo has just perfectly summed up my now-defunct marriage. 
Oooh, yum! When can we expect to see it in stores? I’d like some “King Tut’s Finest” on toast.
I’ll bet honey works even better because it isn’t just sugar; social insects often produce antibiotic-like substances.
Yes she can, and proper names are always capitalized.
And speaking of insects and sugar, while sugar does not necessarily go bad, there is no guarantee that some little bug hasn’t laid a few thousand eggs in your batch. Once I came across a jar of sugar that I had forgotten about in the basement. Turns out that it was a breeding ground for at least a little while considering the number of dead bugs (all seemingly the same species) inside the tightly-closed jar.
Despite the discovery of this new source of protein, I opted to throw it out. 