Blue cheese has such a unique flavor it gets its own descriptor: “blue”
Also called “Ketone”, "Medicinal", and “Perfume-y”, blue cheese flavor is very complex and owes much of its existence to the molds used to produce it.
Some of the characteristic flavor comes about due to the breakdown of fat (called lipolysis). When fat breaks down, fatty acids are formed. (as we’ve discussed before: here, here, and here) The metabolism of a blue mold, Penicillium Roqueforti for example, further transforms those fatty acids into compounds called methyl ketones. 2-heptanone is an example of a methyl ketone that smells similar to blue cheese.
While we often talk about flavors and aromas being caused by certain compounds, it’s important to remember that the unique taste and aroma of cheese is caused by a whole menagerie of chemicals. Cheese flavor is definitely a case of the whole being greater than the sum of its parts.