centuries, where many children were killed by
tuberculosis, undulant fever, and simple food
poisoning contracted from tainted milk. In the
1820s, long before anyone knew about
microbes, some books on domestic economy
advocated boiling all milk before use. Early in
the 20th century, national and local
governments began to regulate the dairy
industry and require that it heat milk to kill
disease microbes.
Today very few U.S. dairies sell raw milk.
They must be certified by the state and
inspected frequently, and the milk carries a
warning label. Raw milk is also rare in
Europe.
Pasteurization and UHT Treatments In the
1860s, the French chemist Louis Pasteur
studied the spoilage of wine and beer and
developed a moderate heat treatment that
preserved them while minimizing changes in
their flavor. It took several decades for