Reader Jimma brought up a good point yesterday: beet sugar can — or once did — have a distinctive smell. Indeed once upon a time beet sugar makers had trouble refining their product to the same degree that cane makers did. This was for a couple of reasons. First, beets grow in soil, so residual soil, molds and bacteria can get into the batch if they’re not thoroughly washed off. Second, beets contain toxic compounds called saponins that they use for defense. As the name implies, these chemicals are related to soaps, which means that they not only have a funky flavor, they can create foam or scum in syrups.
In the last few decades beet sugar makers have figured out how to mitigate all these contaminants. Seldom do they cause off flavors or odors in refined sugar products. However they do make beet molasses unsalable, which is why you never see it on store shelves. It’s usually sold off as animal food.