The production of cream varies slightly between the different types of cream; however the production of most involves the separation of fat from milk which is done through centrifugation. Centrifugation involves the rotation of milk at high speed by an electric motor; the force of this process causes the milk-fat globules to separate from the denser liquid. This process is continued until a cream of the desired fat content is produced.
The cream is then pasteurised (heat treated) to kill off any bacteria that may be present. Pasteurisation also destroys lipases (enzymes) which can affect the flavour of the cream and reduce its shelf life.
Whipped and whipping cream are made by mixing cream with air to roughly double the volume. The air bubbles are captured in a network of fat droplets.
Clotted cream involves a slightly different method of production. Traditionally cows’ milk is strained into a shallow pan and then left for 6–14 hours to allow the cream to rise to the surface of the milk. This milk with a cream layer is then heated in the pan over a water bath to 80-90ºC and is kept there for 40-50 minutes. It is then allowed to cool for 24 hours during which time the cream layer forms a solid crust which can be lifted clear of the skimmed milk creating a product with greater than 55% fat.
The commercial production of clotted cream involves a float cream method. This involves scalding a layer of double cream poured over skimmed milk or whole milk held in swallow trays.
Sterilised cream undergoes a more severe form of heat treatment than pasteurised cream. Sterilisation destroys nearly all the bacteria present meaning it can be kept unopened for several months without the need for refrigeration. The cream is put into cans and heat treated. The high temperatures involved give the cream a caramelised flavour.
Sour cream contains 18% or more milk fat and has been subjected to a bacterial culture resulting in the production of lactic acid, which sours and thickens the product.
Crème Fraîche was originally a French product but is now widely available throughout the world. Crème Fraîche is made by adding bacterial culture to cream which produces a slightly soured cream, however not as sour as sour cream.
In the UK the types of cream are legally defined by the percentage of fat that they contain.
The composition of cream is defined by law - ‘The Cheese and Cream Regulations, 1995'
||Contains no less than 12% milk fat (Not sterilised)
||In coffee, pouring on fruit and desserts|
||Contains no less than 18% milk fat (Not sterilised)
||In coffee, pouring on fruit and desserts, adding to soups and savoury recipes|
||Contains no less than 48% milk fat
||Pouring/spooning cream for desserts, can be whipped for piping onto cakes and pastries|
||Contains no less than 35% milk fat
||Aeration for applications including desserts, cakes and pastry fillings|
||Contains no less than 35% milk fat (Cream has been whipped)
||For dessets, cakes and pastry fillings|
||Contains no less than 55% milk fat (Cream is clotted)
||Used in the classic English cream tea and as a dessert cream. Virtually unique to Cornwall, Devon and Somerset|
||Contains no less than 23% milk fat (Cream is sterilised)
||On or in desserts|