A family of oxygen heterocycles that perfumes roasted malt, chicory, and other heated foods with sweet, caramel, and bready notes. Microbes can brew them too during fermentation, adding complexity to traditional products. The family has a split personality: some members are mycotoxins demanding vigilance, while others show antifungal promise. Careful identification separates friend from foe, and flavorists value the benign ones as building blocks of roasted and caramel character in foods and beverages. Analytical standards help flavorists distinguish desirable pyrones from hazardous ones.