How is skim milk made? If you're interested in raising dairy cattle, you'll want to know how to control the fat content in the milk you sell. If you simply enjoy milk, you'll enjoy this behind-the-scenes look at how it's created.
Types of Milk
The average composition of milk is 87.2% water, 3.7% fat, 3.5% protein, 4.9% lactose and .7% ash. These percentages vary with the breed of the cow and what is fed to the cow.
Skim milk, 2% and 1% milk are made by taking a percentage of the cream from the milk. The cream contains the fat solids in milk. The separated cream is then used to make butter or cheese.
Creating Skim Milk
Raw milk is collected from cows at the farm, then pumped into calibrated, refrigerated, stainless-steel tanks. The milk is then pumped into the tanker trucks and shipped to a processing plant. Once at the processing plant, the milk is either separated or clarified.
Cream, with its heavier fat content, settles to the bottom of storage tanks if the milk is allowed to sit for a short period of time.
Once the separation occurs, a machine simply pushes, or skims, the lower-fat milk off the top. This is how skim milk gets its name. The lighter 1% and 2% milks are made in the same manner, by skimming lower-fat milk off the top. Additional steps separate the milk and fats to reach the targeted fat percentage.
The Food and Drug Administration (FDA) dictates how much fat is in whole milk and skim milk. The average amount of fat in whole milk is 3.67% butterfat and 8.7% solids-not-fat (SNF). Because these percentages vary with the seasons, the breed of cow and what the cow is fed, the minimum federal standards are 3.25% butterfat and 8.25% solids-not-fat.
Skim milk may contain no less than 0.5% butterfat and 8.25% solids-not-fat. Low fat milk ranges from 0.5% to 2% butterfat and must contain 8.25% solids-not-fat.
The separating machine at the milk processing plant measures the amount of fats in the milk and separates enough fat from the milk to meet the federal standards for skim milk, 1% and 2% milk. The percentages you see on the label are based on butterfat content; 1% milk contains 1% butterfat, and 2% milk contains 2% butterfat.
Learn about the types of cows commonly used for dairy farming in the United States.
How much does a cow cost? Learn what determines the price of a cow and how to figure a cow's profitability.