Hazelwood Cream Station in Genesee, Idaho, United States, photographer Russell Lee 1941.
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 homogenization. In un-homogenized 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 produced by livestock grazing on natural pastures 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 color cream. Cream from livestock fed indoors, on grain or grain-based pellets, is white. The chemistry of whole milk is such that it separates into cream and milk best at a temperature of about 100º Fahrenheit.
Types of cream
Here is a list of cream products and associated percentages of fat: in the United States, cream is usually sold as:
Half and half (10.5-18% fat)
Light, coffee, or table cream (18-30% fat)
Medium cream (25% fat)
Whipping or light whipping cream (30-36% fat)
Pegs of cream (15-20%)
Heavy whipping cream (36% or more)
Extra-heavy or manufacturer’s cream (38-40% or more) *generally not available at retail except at some warehouse stores.
Not all grades are defined by all jurisdictions, and the exact fat content ranges vary. The above figures are based on the Code of Federal Regulations, Title 21, Part 131  and a small sample of state regulations.
Other cream products
Sour cream in the U.S. is cream (18% or more milk fat) that has been subjected to a bacterial culture that produces lactic acid (0.5%+), which sours and thickens it.
Crème fraîche is a heavy cream (30–40% milk fat) slightly soured with bacterial culture, but not as sour or as thick as American sour cream. Mexican crema (or cream espesa) is similar to crème fraîche. Kysana smetana is a Central and Eastern European sour cream.
In the UK, clotted cream (similar to Indian malai) is a very high-fat (55%) product processed with heat. For cooking purposes, both single and double cream can be used in cooking, although the former can separate when heated, usually if there is a high acid content. Most UK chefs always use double cream or full-fat crème fraîche when cream is added to a hot sauce, to prevent any problem with it separating or “splitting”. In sweet and savoury custards such as those found in flan fillings, crème brûlées and crème caramels, both types of cream are called for in different recipes depending on how rich a result is called for. It is useful to note that double cream can also be thinned down with water to make an approximation of single cream if necessary.
Cream with 30% or more fat can be turned into whipped cream by mixing it with air. The resulting colloid is roughly double the volume of the original cream as air bubbles are captured in a network of fat droplets. If, however, the whipping is continued, the fat droplets will stick together destroying the colloid and forming butter; the remaining liquid is buttermilk. Confectioner’s sugar (also known as icing sugar) is sometimes added to the colloid in order to stiffen the mixture and to reduce the risk of over whipping.
Whipped cream may be sold ready-to-use in pressurized containers. Nitrous oxide is used as a propellant, and when the cream leaves the nozzle, it produces four times the volume of cream, i.e., twice the volume produced by whipping air into it. Using this technique, it may also be prepared in reusable dispensers, similar to a seltzer siphon bottle, using inexpensive disposable nitrous oxide cartridges. However, the whipped cream produced with nitrous oxide is unstable, and will return to a more or less liquid state within half an hour to one hour. Thus, the method is not suitable for decorating food that will not be immediately served.
Chantilly cream (French: crème Chantilly) is whipped cream with sugar and vanilla. Perfect on top of a waffle with strawberries, it is used in pastry both for its taste and as a decoration. Ice cream is also frequently served with Chantilly. The original recipe was created by François Vatel, maître d’ at the Château de Chantilly in the 17th century. The basic Chantilly is made of whipped cream and sugar although there are slight variations in some countries. The most important thing to get the correct result is the ratio between the two ingredients. The ideal portions are 60 grams of sugar for every 200 millilitres of whipping cream. Before whipping, you can add half a teaspoon of vanilla extract or vanilla bean to taste. Remember to use cold utensils when preparing Chantilly cream!