I used whipping cream that I soured with a buttermilk culture to make creme' fraiche so literally a soured cream. It does not have the sharp bite of the store bought sour creme and is much more mellow and rich and even mildly sweet. The beef broth had tomato in it so my wife was asking why it was not white. Its not really comparable to the boxed variety at all. Onion, garlic, mushrooms etc make it tasty. Always start by carmelizing those onion! I see recipes where a tablespoon of cultured buttermilk is put into a cup of whipping cream for the same purpose and it seems like a much easier way to go. I used a whole carton of cream my first try because I knew I was going to try to use it on a lot of things, but realistically using some sour cream containers you already emptied refilled with whipping cream makes more sense because that is the size you like already.