The Flavor of Caramelized Sugar

The aroma of a simple caramelized sugar has several different notes, among them buttery and milky (from diacetyl), fruity (esters and lactones), flowery, sweet, rum-like, and roasted. As the reactions proceed, the taste of the mixture becomes less sweet as more of the original sugar is destroyed, with more pronounced acidity and eventually bitterness and an irritating, burning sensation. Some of the chemical products in caramel are effective antioxidants and can help protect food flavors from damage during storage.