I have some single cream or double cream in my fridge that's been there over a month & the flavour and taste has degraded into something sour and horrible on it's own but when adding other flavours like salty. Sweet & savory it brings out a nice flavour in dishes that you might not expect, which tastes a bit different from normal cream that hasn't soured.
I wouldn't call it sour cream because I don't know what enzymes & cultures are used to make it , this was just sitting in the fridge for too long but I guess most people would call this maybe gone off cream.
Is there such a thing as matured cream in the same way we have matured cheese?