Mass-produced American chocolate has a distinct flavour that non-Americans describe as tasting a bit like vomit. It’s Milton Snavely Hershey’s fault.
Have you ever eaten a Hershey’s chocolate bar? If you’re American chances are good that you’ve had several in your lifetime; if you’re not then I don’t advise it. To non-Americans, Hershey’s chocolate has a distinct and recognisable aftertaste that is strongly reminiscent of vomit.
The specific compound that triggers this association is butyric acid. It’s one of the chemicals that give us the flavour in Parmesan cheese and slightly rancid butter. If you’ve ever walked past a ginkgo tree when it’s producing seeds you’ll know the smell. Butyric acid is also the smell of vomit, produced by gut microbes.
Most chocolate in the world does not contain large amounts of butyric acid. But when Milton Snavely Hershey began mass-producing chocolate in 1900 some part of the production process produced butyric acid. It was probably lipolysis of the milk, which extends its shelf life but affects its flavour, but I’m also highly suspicious of Hershey’s middle name “Snavely.” It sounds like one of Willy Wonka’s dastardly competitors, or perhaps a minor Harry Potter villain.
Anyway, because this flavour was a part of Hershey’s from the beginning it’s now inextricably linked to chocolate in the American flavour palate. For everyone else… less so.