Skim milk is milk with all of the butterfat (cream) removed. The butterfat rises to the top, and is easy to skim off. The remainder can be removed by centrifuge. What is left is skim milk. It is powdered by the simple industrial process of evaporation.
Milk is centrifuged to separate the cream/fat.
Yes Centrifugation is the most common technique used to separate cream from milk (especially raw cow milk).
centrifugation
Centrifugal force is used in commercial dairy factories. Gravity can be used with raw milk to get cream floating to the top.
You don't separate crream from curd, you separate whey from curd. Cream is skimmed from the top of milk as it sits and the cream floats to the top. Then the milk is used to make curds and whey by adding a curdling agent like rennet. The curds form and the clear liquid they float in is whey. Then you can strain the curds from the whey by pouring them through cheese cloth.
This depends entirely on the equipment at your disposal. Traditional methods let the milk stand overnight before skimming off the cream that settled to the top of the tank. High speed centrifugal separators are mostly used these days. With this equipment the process is very quick. Some of the smaller separators can handle 3000 - 7000L of milk per hour.
The old tool is a hand-cranked butter churn. It was used in the past to separate cream from milk and churn the cream into butter by manually turning the crank, causing the cream to agitate and eventually form butter.
Standardisation is when cream is removed from the milk and then added back to a specific butterfat. For instance - cream is first removed, leaving skim milk and cream. The cream is then added back into the milk phase to 2.0% to give low fat milk. The rest of the cream is used for cream or butter.
The toned milk should contain a minimum of 3.0 per cent fat and 8.5 per cent non-fat solids.Centrifugation is used to make the skimmed (low or non-fat) milk needed to reconstitute the toned milk, made up from whole milk and this skimmed milk with water to obtain the 3.0/8.5 spec's on fat/non-fat solids.
churning is the process of shaking butter,cream,milk and various forms of butter churn have been used for the purpose.
raised on a farm I know this a cream separator a device that separates the heavier milk from the cream by centrifugal force
Whole milk or regular cream is typically used.