Raw Milk in Portland, Oregon

A component-by-component reference for what pasteurization measurably changes in milk, and what it doesn’t, drawing on 14 separately researched findings.

How long raw milk actually lasts depends on starting quality and storage temperature, not a fixed number. A complete, research-backed guide to storing it well.

Lactic acid bacteria in soured raw milk measurably inhibit major pathogens in lab testing, but the effect has real, documented limits.

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.