Can sugar go "bad"?

My girlfriend is trying to make tart filling right now and the recipe calls for her to caramelize sugar. On our first attempt at this, 99% of the sugar melted, however rice sized chunks still remained. With the second attempt we tried adding a little bit of water and continuously stirring; this resulted in no melting and even larger peanut M&M sized chunks. This seems to be a simple process and we’re not quite sure where we are going wrong. Which brings me to my question…can sugar go “bad”?

My thinking is that at some point in the life sugar, sitting in a room temperature cabinet, that it could lose some of it’s consistent properties…such as the ability to melt correctly at certain temperatures? Is this true?

No. It won’t go bad. Dissolve the sugar in water and go from there, as the water boils off it will caramelize.

Oh and use a candy thermometer.

Heh, and on review, you should also include a dash of corn syrup, because the glucose will stop the sugar from forming crystals, which might be the problem you are having if you aren’t using a spotlessly clean pan and aren’t rinsing down the sides.

The only two things I can think of that will make sugar go bad are 1) bugs getting into it and b) improperly stored sugar absorbing moisture. Either one of those things, you’d notice. The sugar is fine, just try the tips you’ve been given to improve your technique :slight_smile:

Several years ago, my father found a 50 pound bag of sugar in the rafters of a house he was renovating. From the packaging, he figured it was World War II era sugar - seemed that someone was hording it and forgot about it.

His sister (my aunt) was a baker at the time, and she took the sugar and called the company to see if it was still good. I don’t remember the brand, but they told her as long as it was dry and clean (ie, the package wasn’t torn, mice didn’t get into it, etc) it should be just fine.

She used it and had no problems at all.

Wasn’t there a 3,000 year old jar of honey found in some Egyptian tomb, and it was still good? Although I guess it had gotten kind of hardened by then.

How about maple syrup? I bought some in Canada several years ago and never used it, but am thinking about it . . .

Honey and syrup are sugar solutions. Sugar is very hygroscopic, meaning it sucks up lots of water. Because of this, almost no water is left to support bacterial or fungal growth, so they almost never go bad. There are one or two species of yeast that can grow very slowly in honey, but other than that, they’re good.

Your maple syrup (like old honey) may have crystallized, but if so, you may be able to “revive” it by heating it (just a few seconds at a time; it gets very hot, very fast) in the microwave. I’ve revived crystallized honey that way.

I have had real maple syrup go bad. High-end brands advise you to refrigerate after opening.


It’s never been opened and is in a clear container in the shape of a half moon. No visible crystals forming. Been using it as a decoration next to the pickeled peppers.

Dry sugar stays very stable. Damp sugar is digested by organisms. Sugar can also have contamination. The easiest thing you could do is sift the sugar before you use it.

Maple syrup can grow mold on top, but as I understand it, simply remove the top layer of mold, and use. If it’s gotten mixed into the syrup (by pouring, most likely. The sloshing action in the jug/container causes pieces to separate from the layer, and mix into the depths of the syrup), simply filter it out.


I had some that smelled strongly of alcohol, after it had been in the fridge for quite awhile.

I dubbed it Maple Schnapps, but didn’t have the courage to try it. It could have been contaminated by something, but I’m not sure what.

I’m no expert, but have made caramel desserts a few times, and I’m guessing your sugar is fine, but you just stopped too soon. When I do a dry-sugar caramel, it seems like there’s a long wait before the sugar starts to melt, then a bunch of it melts quickly, then another long wait for the very last of the sugar to melt. I say, just keep going, as long as the melted sugar isn’t too dark.
Worst comes to worst, you just pick out the few hard lumps of sugar from the caramel, but I think the lumps will also melt with a little more heating time.

Yeah, I forgot to mention that syrups tend to have more water than honey, and so are more likely to suffer from microbial invasion. I don’t recall offhand the relative water activity levels. Sorry…