Have you ever wondered how milk goes from the dairy farm to the grocery stores? We toured a local dairy processing plant in Burnaby to learn all about how milk is processed.
At the farm, all the fresh milk is stored in a temperature regulated bulk tank. Every other day a dairy truck goes to the farm, picks up the milk and delivers it to the processing plant. The milk truck driver collects a sample and tests it for quality. This is an important step because to ensure efficiency and freshness. The milk truck picks up milk from multiple dairy farms before delivering it to the processing plant.
|A sample of milk is taken at each farm.|
When the milk has arrived at the processing plant it is tested again. All Canadian milk is free of anti-biotics and growth hormones, and its reputation for high quality is world renowned. Once the milk passes all the quality tests, it goes through the pasteurizer. The pasteurization process heats the milk up to 72 degrees for 16 seconds and then rapidly cools it down to 4 degrees. The pasteurizer is designed at an angle to increase the amount of surface area, allowing the heating and cooling process to be done quickly. The angle of the pasteurizer also allows the milk to be constantly flowing so that it can be held at a consistent temperature.
|Ron shows us a pasteurizer. Notice how it looks similar to a ladder and each layer is tiled slighty. The angle is important to help bring the temperature of milk to a consistent temperature.|
After the milk is pasteurized it goes through a separator. The separator spins the milk at an ultra-high-speed (6000 rpm) to separate the cream from the milk. Different amounts of cream are then recombined with the milk to create dairy products of different milk fat. For example, to make 1% partially skimmed milk, only 1% of the milk fat is put back in. To recombine the milk fat with other components of milk, a high-pressure process called homogenization is used.
From here, the milk is sent through stainless-steel pipes across the processing facility to be either bottled and sent to the grocery stores, or made into dairy products such as cheese, yogurt and ice-cream.
|After the milk is bottled, it is prepped to be shipped to stores.|
After the milk has been processed, the tanks are cleaned. To help reduce water consumption, the pH of water used to clean the tanks and pipes pasteurized milk has come in contact with, is neutralized and reused in the initial rinse cycles of unpasteurized milk tanks.
Just as dairy farmers have to follow strict quality standards, processors too must test the milk for quality throughout the pasteurization, separation and homogenization process. In addition to ensuring the milk is at the proper temperature and consistency, processors must also meet government standards to ensure excess air is not incorporated. The equipment used for testing the milk is annually calibrated and its controls are locked by a government official.
Our tour guide Ron shows us one of the equipments they use to ensure no excess air is incorporated into the milk during the processing stage.
Did you learn something new about milk’s journey from the farm to the grocery store?
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