Out Of The Holding Truck, Into The Tank: How To Properly Move Milk
Getting milk from the farm to the grocery store shelf involves a number of important transitions: from cow to milk tank, from there to the truck’s tank, from the truck to the processing facility, and from there to the packaging you’ll bring home from the store. At each point, care must be taken to ensure that all equipment and tools that come into contact with the milk are clean and sterile, to keep the milk free from bacteria and contaminants, and to minimize waste.
Bulk milk trucks make pickups at several different farms, combining the milk from each, before delivering the total collection to processing facilities for testing and preparation. Because more stops means more chances of contamination, precautions must be taken to ensure that the milk collected from each farm stays clean and sanitary at every step along the way.
- Before Transferring
Before transferring the milk onto the truck, the milk hauler must ensure that all required testing, sampling and measuring has been completed—including ensuring that the milk is free from obvious defects that could indicate spoilage or souring. If the bulk tank’s agitator has been running, it should also be turned off either before the pumping begins, or at least before the level of milk in the tank gets below the top of the agitator, to prevent loss of milk.
- Connecting The Hose
Every dairy house is equipped with a hose port with a self-closing door. Milk haulers should always use this door so that the milk house door can remain closed, keeping out wandering animals or pests. Using this door also helps to prevent crimping, bending, and other potential sources of damage to the transfer hose, which helps prevent issues in the transferring process and damage to equipment. To connect the transfer hose, the driver should remove the hose cap (this cap must be kept clean and protected at all times, especially since the interior of the cap comes into contact with milk). This can be achieved by placing it on the upturned outlet cap when not in use.
- The Transfer Process
Before starting the pump, the inlet valve on the tank truck and the outlet valve on the farm bulk tank should be open—especially if the truck is equipped with a positive displacement pump with no safety bypass. (Failure to do so could cause the hose to collapse or could blow a gasket from excess pressure). As the milk is pumped out of the farm’s bulk tank, the driver should be watching to ensure that there is no foreign matter or precipitate remaining in the tank after the liquid has been removed (if there is, this should be noted and reported to supervisors). Once the transfer is complete, the pump should be turned off as soon as possible. Running the pump after all of the milk has been removed from the farm’s bulk tanks will introduce air into the small volume of milk left in the pump, which could cause it to go rancid.
Once the tanker hose has been disconnected—and not before—the milk hauler should rinse the farm’s bulk tank with warm water (otherwise he or she risks contaminating the milk with rinse water). This step expedites the cleaning and sanitization process for the producer. The milk hauler should also ensure that the pump, agitator and refrigeration unit have been turned off, where necessary, and ensure that all valves are closed and all access points are sealed, on both the bulk tank and the truck, for safety and security during transport.
- Best Practices
All outlet caps should remain on when an outlet is not being used, to prevent contamination. Milk haulers should also ensure that they have enough space in their truck’s tank to accommodate all of the milk in a farm’s bulk tank before beginning to pump, as the farm’s tanks should never be left partially full. Additionally, to prevent contamination of a full truckload because of a problematic batch, milk can only be collected from bulk tanks at the farm—not from any other container.
Following this protocol ensures consistency and safety for everyone involved, and helps minimize waste—both key criteria of effective and successful milk collections. The result is that more milk makes the safe and sanitary transition from farm to processing facility. Better yields for farmers and processors with lower chances of contamination, means consistently affordable milk prices for everyone. In other words, we all win.