Synthetics
Isovaleric acid smells like a pungent, sour blend of cheese, dairy, and fruity, fatty notes.
Mosciano, Gerard P&F 18, No. 5, 39, (1993): Cheese, dairy, acidic, sour, pungent, fruity, stinky, ripe fatty and fruity notes
Luebke, William tgsc, (1989): Sour stinky feet sweaty cheese tropical
Ernesto Ventós: Sour,cheesy,fruity,fermented,woody
Mane: Sour milky cheesy