At the Dairy

• Dairy cows, like our Holsteins, can produce up to ten gallons of milk a day.
• Most dairies milk their cows 2-3 times a day, to empty their udders and keep the cows comfortable.
• The milk at the farm is called raw milk because it hasn’t been processed for human consumption yet.
• As the cows are milked, the milk is immediately cooled.
  
  • Bulk milk tanks will cool milk from about 101* F to 34-36* F in a short period of time and will maintain that temperature until the milk leaves the farm.
  • An agitator in the bulk tank mixes the milk periodically to maintain even temperature throughout.
  • The milk is never exposed to outside air or airborne contaminants.

Leaving the Dairy

• Every day or two, milk is taken from the dairy in an insulated tanker truck to a dairy processing plant. Within the tanker the milk is kept at 38 degrees.
  
  • The tanker holds approximately 6000 gallons of milk and is always cleaned and sanitized before milk is loaded.
• The hauler checks the milk to make sure it meets certain standards of freshness and collects several samples from each farm milk tank.
• Once the milk arrives at the processing plant it is tested again before being unloaded.

Processing the Milk

• Milk is transported to one of several processing plants that manufacture products like cheese, ice cream, milk, yogurt, butter, or milk powder.
• The milk samples are tested at a laboratory by lab technicians to make sure the milk is safe and fresh to be processed for us to drink.
  
  • One sample is immediately checked for temperature. If the temperature of the milk is above 40°F, the entire load is discarded.
  • Another sample is tested for bacteria and antibiotics. In the rare event that the tanker of milk tests positive, the entire load is discarded.
  • Milk is never unloaded until it passes all tests.
  • The technician also tests the butterfat content. Butterfat is also called cream.
• When milk passes “inspection,” processing begins.
• Once the tank truck driver gets the okay from the lab, the pumping begins.
  
  • Milk is pumped into large, refrigerated storage tanks or silos.
• One of the first stops is the separator.

The Separator

• Milk is pumped into a separator that spins the milk to separate cream, which is lighter, from the skim.
  
  • What do we call milk that has the butterfat removed? Nonfat milk or skim milk
• The desired amount of cream can then be added back to the skim later to obtain milk standard for 1%, 2%, or whole milk which is 3.25% fat. Excess cream can then be used to make ice cream and butter.
• Some of the milk is even pumped to mixing tanks. Here other ingredients are added to make flavored milk.

The Homogenizer

• The milk is pumped into a homogenizer (Homogenized means the same all the way through) that breaks up the fat globules and makes them smaller.
  
  • Milk is forced through very small holes under great pressure.
  • This breaks the butterfat particles into tiny, uniform pieces.
  • A protein coat surrounds each butterfat piece. This keeps the butterfat from clumping back together.
• This makes the milk have consistent flavor when bottled.
• If milk were not homogenized, the cream would rise to the top. You would have the shake or stir the milk before drinking it.

Pasteurization

• In 1865, a French scientist named Louis Pasteur discovered that heating liquids to high temperatures kills microorganisms.
• Milk is pasteurized which kills bacteria that may be harmful to health.
  
  • Heating milk to 165* F for 15 seconds then quickly cooling it down to 35* F accomplishes this.
• Pasteurization protects the purity and flavor of milk without influencing the nutrient value.

Preparing Milk for You

• Milk is always bottled in sterile containers that are fed down a conveyor belt to the filling station.
• Containers (bottles or cartons, in some countries they even use plastic bags) are automatically filled with the proper amount of milk, sealed and capped.
• Milk is stored in a refrigerated room that is kept at 36 degrees until it is ready to be transported to grocery stores or schools.
• Refrigerated trucks are used to deliver bottled milk to its retail destination.
• It takes only about two days from the time milk leaves the cow until it reaches the grocery store.
• Still, some milk doesn’t get bottled for drinking, instead it’s set aside for further processing to make ice cream, cheese, yogurt, butter, or other dairy products.

Milk is Safe

• Milk is one of the safest food/drinks you can consume:
  
  • Human hands never touch the milk.
  • The milk is tested to make sure it is fresh and clean.
  • Milk is always kept cold as it travels from the cow to dairy processing plant and finally to the store or school.
  • These steps are important to make sure that milk is always safe and fresh for us to drink.