One of the most striking aspects of the shift over the past century to mechanized food production is how the local logistics have shifted.
For example, think of a dairy farm. In the pre-refrigeration past, most of the dairy products, particularly fresh milk and cream, were produced at the farm itself. Butter could be made at the farm, or the cream brought to a nearby butter factory. Cheese could be made at the farm, or by nearby cheesemakers who bought the whole milk at the farm. The dairy industry still works like that in much of the world. When I lived in Switzerland, we had a dairy in our little village, nestled in the base of the hill. Early each morning, you could see the hausfraus walking back up the hill, toting their full milk pails back from the dairy.
Our current system in the United States bears almost no resemblance to that small-scale, localized dairy of the past. With the advent of refrigeration, mechanical milking, and better transportation, the industry shifted to a centralized, large-scale specialized production system. Using milking machines, modern dairies are ably to milk many more cows than their hand-milked predecessors. More cows meant much more milk. Instead of selling the milk locally, it is refrigerated in large holding tanks, before a milk transport tanker arrived to bring the milk to a factory. At the factory, it’s homogenized, pasteurized, and packaged before being shipped to a central distributor, and from there to various grocery stores.