It’s more simple than that. Acids are sour. Coffee has acids that are transformed by the roasting process. Light roasts do this less. Some people like that tast

It’s more simple than that. Acids are sour. Coffee has acids that are transformed by the roasting process. Light roasts do this less. Some people like that taste and others don’t. Those that do like it often act superior and treat the other group as uncultured.