Scientists cannot yet predict a chemical’s smell simply from its molecular shape, explains lead author Dietmar Krautwurst, a molecular cell biologist at the Technical University of Munich. For example, the chemical responsible for caramel scent, called furaneol, has also been described as smelling like strawberries or cotton candy. But just a tiny tweak in the chemical structure makes it recognizable by a different receptor, giving it a savory and herby scent instead, Krautwurst says.

— Read more in How We Detect Caramel Candy Scent at Scientific American.