Cream splitting or separating
Splitting is usually applied to dairy products such cream, yogurt or milk when they curdle or separate into curds and whey. It generally occurs when they are added to a sauce and heated close to boiling point. Once the liquid has split it cannot be recovered. Apart from when cheesemaking, this is undesirable.
Because of their high fat content, crème fraiche or double cream are particularly useful when finishing sauces because they are less likely to split. However, "light" crème fraiche with a low fat content is more likely to curdle when heated.