I heard that it is a manufactured taste to emulate the original taste. Something along the lines of when Hershey was first making chocolate there was no good refrigeration method which meant the milk that was used was sour. Then as the manufacturing process changed and fresher milk was used the flavour changed but people didn't like it and so they started putting stuff in to make it taste like it used to. I've never known how close to the truth this was but I've told it to a number of people since I found out. Think there's also something about it giving a longer shelf life or something but that's boring.
I heard that it is a manufactured taste to emulate the original taste. Something along the lines of when Hershey was first making chocolate there was no good refrigeration method which meant the milk that was used was sour. Then as the manufacturing process changed and fresher milk was used the flavour changed but people didn't like it and so they started putting stuff in to make it taste like it used to. I've never known how close to the truth this was but I've told it to a number of people since I found out. Think there's also something about it giving a longer shelf life or something but that's boring.