Whipped Cream
Whipped cream is a cream of milk with a fat content of at least 35% and has a doubled volume because of the whipping of air in the product.
In the Netherlands and Flanders, whipped cream is a titbit, sweetened with sugar. Whipped cream is available as whipping cream in cups or bags and has yet to be whipped to become whipped cream, or as whipped cream which already has been whipped. The whipped cream is also already sweetened with sugar and wrapped in aerosols. In this whipped cream, small amounts of N2O (laughing gas) are present as propellant, in order to obtain a whipped cream immediately.
Production whipped cream
The production of whipping cream will be described first, followed by a short description of the production of whipped cream in aerosols.
Whipping cream
Raw materials
Whipping cream is made from whole milk. It is important that this milk contains little heat-resistant bacteria’s, because the presence of Bacillus Cereus can lead to an instable fat emulsion. The formation of heat-resistant lipase due to psychrotroph bacteria’s is also harmful and may not occur. To prevent auto-oxidation leading to spoiled taste, not even small amounts of cupper are allowed to be present in the milk.
Pasteurizing
Before the cream is separated from the milk, the liquid is pasteurised at 72°C for 15 seconds to inactivate lipase.
Separating cream
To obtain cream with the proper fat content, the cream is separated from the milk by means of a separator. This separating generally takes place at a temperature of approximately 50°C, because a good separation of the fat takes place at this temperature. However, the cream can also be separated from cold milk. By separating at approximately 7°C, a cream is obtained with good whipping characteristics, although the fat content of the milk obtained at this temperature is usually higher than normally.
Standardizing
The cream is standardized to a fat content of at least 35% by means of the previously obtained cream and milk. To lower the serum discharge of the whipped cream, skimmed milk powder or thickenings agents can be added to the standardized cream.
Pasteurizing
After the standardizing, the cream is pasteurized again. The time and temperature combination differs per concern, but a standpasteurization for 30 minutes at 80°C or heating up too 100°C in a heat exchanger is not uncommon. It is also possible to pasteurize the cream for 20 minutes at 103°C while it is already wrapped.
When one wants to remove unwanted scents from the cream, one can choose to keep the cream moving at high temperature in an open kettle. The cream has to be kept moving very accurately, for clotting of the balls of fat needs to be prevented.
Cooling and wrapping
The whole is cooled to 5°C after pasteurization and then wrapped in glass bottles or in disposable wrappings.
Afterwards pasteurizing / sterilizing
To ensure the product keeps fresh for a longer period of time, the cream can be pasteurized afterwards or sterilized. When the cream is sterilized, it first needs to be homogenized lightly (at 1,5 bar), to prevent coalescence. However, due to the homogenizing, the whipping characteristics of the cream deteriorate. It is therefore sensible to add an emulsifier to the cream. After the final pasteurizing or sterilizing, the whole needs to be cooled quickly to at least 5°C.
Rebodying
The whipping characteristics of the cream can be improved by keeping the cream, after cooling to 5°C, at this temperature for several hours. The cream is then heated shortly to 20 to 30°C and cooled again to 5°C.
Crystallizing
Finally, the cream has to be kept at 4°C for 24 hours, in order for the milk fat to crystallize, which improves the whipping characteristics.
Whipped cream
The cream which is obtained by separation and standardisation is mixed in a mixing tank with emulsifiers and stabilizers. The whole is then sterilized to ensure a longer freshness. The sterilization process is the same for whipped cream as for whipping cream. After cooling the whole to 5°C, the aerosols are aseptically filled with the cream. Before the aerosols are filled, they are brought to an overpressure cabin, where they are heated to 160°C. When the aerosols are filled, a cap is placed on top of them. The propellant is then injected in the cream. The gas N2O is usually used, because it dissolves relatively good in fat. The propellant dissolves in the cream, but when the cream is pushed out of the aerosol under pressure, the gas leaves the solution again. The laughing gas therefore is used to push the cream out. However, the whipped cream will return to a more or less liquid state again after a short period of time, because the laughing gas diffuses out of the cream as it is not present in the atmosphere.
