Cream (from Greek chrisma, literally "an anointing") is a dairy product that is composed of the higher-butterfat layer skimmed from the top of milk before homogenisation. In un-homogenised milk, over time, the lighter fat rises to the top.
In the industrial production of cream this process is accelerated by using centrifuges called "separators". In many countries, cream is sold in several grades depending on total butterfat content. Cream can be dried to a powder for shipment to distant markets.
Cream produced by cows (particularly Jersey cattle) grazing on natural pasture often contains some natural carotenoid pigments derived from the plants they eat; this gives the cream a slight yellow tone, hence the name of the yellowish-white colour cream. Cream from cows fed indoors, on grain or grain-based pellets, is white.
Cows' milk contains butterfat which is removed from milk using a centrifuge system. The longer the milk is centrifuged, the thicker the cream becomes.
Double cream is very rich, with a fat content of 48 per cent, making it the most versatile cream because it withstands boiling, whips and freezes well.
It can be served as is as a thick pouring cream with fruit, pies, cake, puddings, etc. In fact, where North Americans would reach for ice cream, Brits will reach for Double Cream (or custard).
Double Cream can not only be whipped, it will whip up firmer than whipping cream, which is why fancy cake makers will prefer it to whipping cream. If you want it less firm but to have more volume, add a tablespoon of milk or an egg white per 5 oz (2/3 cup / 150ml) before whipping (this lowers the butterfat content a bit, making it a bit less dense, allowing more air in and thus more volume.) Don't overwhip, though, or it will take on a grainy appearance, and if you kept on overwhipping, you'd practically end up with butter.
Irish Coffee connoisseurs say that aerosol foam is a poor substitute for Double Cream.
Double Cream isn't a good substitute for regular cream in normal coffees -- it will indeed try to float on the top and is very hard to stir in.
Can be stored in a fridge for up to five days
Can be frozen for up to two months, but when thawed, use for cooking rather than as a topping.
A lighter version of double cream with a fat content of over 35 per cent - the minimum amount necessary to allow it to stay firm once beaten. It's the fat globules that trap whisked air, creating the characteristic foam and texture of whipped cream. Whipping cream whips well without being quite as rich as double cream and also makes a slightly lighter pouring cream. It makes a good topping for desserts, meringues and puddings that need a slightly lighter touch.
British Single Cream, with 18% butterfat content, is equivalent to what North Americans call Table Cream or Coffee Cream (if those have 18% fat content as well; some dairy producers will produce a table cream with up to 30% butterfat content.)
Single Cream is homogenised to keep the butterfat from separating out from the milk during transport and storage.
It is a good pouring cream and good for cooking with in any recipes that call for milk, when you want more creaminess than just milk would give. But don't let it boil, as it takes a much higher-fat cream to not curdle if boiled. It is also good in coffee.
Will not whip as the fat content is not high enough.
Storage Cannot be frozen; will separate upon thawing
Thick, rich and indulgent with the consistency of soft butter, clotted cream is made by heating normal cream to evaporate some of the liquids. It has at least 55 per cent butter fat giving it a pale yellow colour, often topped with a deeper yellow crust. It's traditionally made in Devon and Cornwall and served with scones or desserts or made into ice cream. If you buy an ice cream in Devon or Cornwall it's usual for your ice cream to be topped off with a spoonful of clotted cream.
Sour Cream has a taste that is mildly acidic or sour. It has been used for a long, long time in Eastern European cooking, and features as well in many German and Russian recipes. The popularity has made its way to America via immigration, even though the Sour Cream is now dolloped on jacket potatoes and refried beans instead of borscht.
Traditionally, it was made by letting unpasteurized cream sour naturally from the bacteria in it. The lactic acid produced by the bacteria eating the milk protein would thicken the cream and make it tangy. This can't work anymore because pasteurisation will have killed off the bacteria.
Today, producers start with a pasteurised cream of 18% butterfat that has been homogenised to make it thicker . A starter culture of bacteria which make the lactic acid is added. (This process is very similar to Crème Fraîche, except Crème Fraîche starts with cream with almost double the butterfat content.) The now-Sour Cream is then re-pasteurised to kill those bacteria and stop the process, which extends of course the shelf life. Stabilizers and/or gelatin are sometimes added.
Lower-fat Sour Creams start with lower-fat creams. Non-fat Sour Cream is made from skimmed milk, and to make up for the absence of fat, is thickened with things such as starch or gelatine.
Crème Fraîche (pronounced krem fresh, for those whose French is rusty) is a thick cream with between 30 to 40% butterfat, usually more towards 40 than 30. It's so thick that you would generally spoon it rather than pour it.
It has a slightly sour taste, contrary to what the "fresh" part of its name might indicate. The taste comes from the bacteria culture used to thicken it. It tastes something like Sour Cream, though not with so pronounced a tang.
It has been widely used in France for a long time, and in Britain has become such a commonplace ingredient that there are even half-fat versions (15% fat).
Crème Fraîche evolved in the days before refrigeration (and pasteurisation). Milk fresh from a cow was left in pails to cool down overnight. The cream would be collected off the top the next day (note: in warm weather, this might happen overnight; in cooler weather, this could take up to 2 or 3 days) and added to previously-collected cream kept in a separate pot at a cool, cellar temperature. The cream would ferment and develop a natural lactic acid that thickened the cream and matured it, giving it a slightly-tangy taste. At the end of which, when you had enough cream collected from several milkings to suit your purposes, perhaps half the cream would be used to make butter, and the other half used as cream.
The cream could be stored without refrigeration for up to a week, because the lactic acid also helped to preserve it (the bacteria that produced the lactic acid consumed the milk proteins which, if present, speeds up dairy products going rancid.)
Ironically, another French discovery -- pasteurisation -- killed off this process, because in halting the natural maturation process with pasteurisation, cream left out no longer matures -- it just goes bad. The pasteurisation process destroys the bacteria that would have consumed the milk proteins.
But never mind -- the farmhouse production techniques wouldn't make enough to meet market demand today, anyway. So, cream at factories is processed in large stainless steel vats to which a small amount of culture is introduced, and the cream is allowed to mature at room temperature for 18 hours to create the same thickness and tangy-ness as was created before.
Creme Fraiche doesn't curdle when heated, so it is great for making cream sauces and for adding to soups. Good with fruit and desserts, for making salad dressings and dips. Can be whipped.