Mannitol is a six-carbon sugar alcohol (polyol) that looks like a fine, non-sticky white powder and tastes cleanly sweet with a mild cooling touch. It is only about half to two-thirds as sweet as table sugar, dissolves poorly and — crucially — barely absorbs moisture from the air, which makes it the classic "dusting sugar" that keeps marshmallow candies, chewing gum and spun sugar dry and free-flowing instead of tacky.
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