Dredging up this old thread with some comments from a total chocolate and pastry nerd. Lots of misconceptions in this thread.
1. Hershey's tastes that way because it's supposed to taste that way, not because someone screwed up. Hershey's smells slightly like vomit / sour milk because it contains elevated levels of butyric acid. This is due to Hershey's use of the "Hershey Process", which it has used since the turn of the century. The Hershey Process (which is a trade secret) was designed to produce chocolate more cheaply back when raw cacao was extremely expensive and a chocolate bar was a luxury good. This is no longer the case. but because of the long history of the Hershey Bar and Kisses being sold in the US, Americans are used to this flavor in Hershey's chocolate and the company has stuck with the process. The rest of the world is not used to the taste and considers it a sign of poor manufacturing. What people unfamiliar with Hershey's chocolate might consider to be a fault or "mistake" in making the chocolate is actually a deliberately introduced flavor. This IN NO WAY excuses Hershey for the (IMO) awful taste of a standard Hershey bar. I think Hershey's should abandon the Hershey's Process. It no longer makes sense and once you notice it, it's terrible. PWe should all persuade Hershey to ditch the outdated process.
2. A standard Hershey's bar contains far more cocao than many popular European chocolate bars. The EU minimum percentage is only 1% while a Hershey's bar contains about 11% cacao solids. The UK is (in)famous for have a pretty lax definition of "chocolate", something that sparked a trade war about 15 years ago. In fact, many bars that are sold as "chocolate" in the UK could not legally be sold in the US as "chocolate" because the cacao content is too low or because the manufacturing process introduces non-cacao fat. An example of this is Cadbury Dairy Milk which is based on (much cheaper) palm oil and thus is not chocolate in a purist sense. Because of this, Dairy Milk is contract manufactured in the US without the palm oil for sale in the US. So from a purist sense, a Hershey's Bar is more "real chocolate" than the vaunted Dairy Milk. So there, snotty Brits.
3. Hershey owns several high end brands that produce boutique world class chocolate (Dagoba, Scharffen-Berger etc). Also, many products produced by Hershey's don't follow the Hershey Process and thus exclude the "sour" taste (example: "Pot of Gold"). The company knows how to make unbelievably good chocolate.
I love milk chocolate including Hershey's kisses, M&Ms (U.S. version) and almond chocolate bars. I like dark chocolate but not as much as milk chocolate and the rich Belgian style chocolates do nothing for me, too rich/sweet. I've never had European version M&Ms. How different are they?
