Isovaleraldehyde

An aldehyde — synonym 3-methylbutanal — and a volatile flavour compound identified in fermented and heated foods. It carries malty, fruity notes that contribute to the aroma of products such as cheese, beer, and cocoa. Flavour chemists track it as part of the Strecker aldehyde family that shapes the character of cooked and fermented flavours. Its concentration reflects amino-acid breakdown during fermentation and heating, linking process conditions to aroma. Chocolate makers monitor it among the aldehydes of cocoa fermentation. Its malty character is desirable in beer but a fault in milk.