REALLY?

Is it true that sugar, molasses and honey never go bad?

They can if they are diluted. “It’s almost all about water,” said Kathie T. Hodge, associate professor of mycology at Cornell University.

Molds and bacteria cannot survive on very sugary foods, she said, because the concentrated sugar, like salt, has the effect of drawing moisture out of cells. The attacking microbes tend to dehydrate.

“We talk about a food’s water activity, how much of its water is available,” Hodge said. “Sugar, honey, molasses and maple syrup have very low water activity. In fact, they will pull water right out of the air.”

But that is why maple syrup left on the table will absorb water from a steamy kitchen and eventually become dilute enough to support mold growth, Hodge said.

Molasses is 50 percent to 75 percent sugar, preventing most bacteria and fungi from growing on it, but if it is diluted, microbes will eat it and spoil it. “That’s how we get rum,” Hodge said.

Honey has low water activity and a very high acid level, she said, and also contains chemicals made by plants and bees that suppress the growth of fungi and bacteria.

A handful of organisms, especially some fungi, are good at growing on things with low water activity, Hodge said. Such organisms, which love dry places, are called xerophiles.

“But even for them, a sugar cube is too dry,” Hodge said.