Heavy cream, also known as whipping cream, is an ingredient that is frequently called for in recipes. Cream is the thick, fat-rich part of milk, which rises to the top when milk is fresh and is skimmed off. The type of cream is determined by its fat content. Heavy cream has a fat content between 36 and 40%. A high milkfat will add tenderness and moisture to a baked good, just like adding most other types of fat. For instance, many scones are called cream scones because they are made with cream. It is certainly possible to substitute some other type of milk for the cream in these recipes and have them come out, but they won’t be nearly as tender or moist as a scone that is actually made with heavy cream. Heavy cream is also used to make whipping cream. The fat in the cream is what helps stabilize it after it is whipped, and why you can’t whip just any old dairy product into whipped cream with a whisk. The fat also prevents the cream from freezing too hard when it is used in ice cream, leading to a creamier finished product.
There is one type of heavy cream, called manufacturing cream, that is used commercially by bakers, cooks and bakeries. It has an even higher fat content of 40-50%. This can be substituted to regular heavy cream (it is often found at bulk stores, but would not be found at a grocery store with regular cream), but otherwise there are no real substitutes for heavy cream when you need it. The fact that heavy can whip and hold its structure so well makes it unique. And because its high fat content gives lightness to all kinds of dessert, from featherweight mousses to silky ice cream to tender scones, it is an ingredient that is generally worth using when called for to get the best results you can.