Raw Milk in West Chester, Pennsylvania

An IgM-lipoprotein complex clusters fat globules together in cold raw milk, accelerating creaming well beyond what density alone would predict.

Refrigerating milk causes one of its four major casein proteins to leave its normal structure entirely, a reversible effect documented since 1977.

In some cows’ milk, simply cooling it after milking is enough to trigger rancidity, no bacteria or physical damage required.

Freezing raw milk causes real structural damage from ice crystals, and how you freeze and thaw it changes how much. Here is what the research documents.

Refrigeration favors a specific category of bacteria whose enzymes often survive pasteurization and even UHT heat completely intact.

Unfortified milk contains too little vitamin D to matter nutritionally, and fortification, not pasteurization, supplies almost all of what is on the label.