Cleaning up the Milk Supply

Last week’s protest by British dairy farmers, and their threat to disrupt supplies during the Olympic Games, made me think about milk.   Specifically about how accustomed we are to having clean milk available all year round.  In Britain we might worry that too much double cream is unhealthy but we can assume that milk, and other dairy products, are safe.

Franz Ritter von Soxhlet, the German chemist who developed pasteurization in the late 19th century.

During the 18th and 19th century milk could be a source of illness.   Leaving aside adulteration, the way milk was produced and transported allowed harmful micro-organisms to multiply.  Milk cows were often kept in overcrowded conditions, equipment was not always cleaned properly and the lack of refrigeration made things worse.   Tuberculosis was one of the diseases that could be spread by contaminated milk but the lack of certainty about how the disease spread meant there was plenty of room for disagreement.  Some argued that the milk supply could be cleaned up by good hygiene practices alone.  Others argued that pasteurization of milk was absolutely essential.  There were even voices suggesting that the best solution would be for the government to take over milk production as in this 1899 Fabian Society leaflet.

Of all the people who helped clean up the milk supply the Medical Officers of Health deserve a special mention.  These government officials, who began to be appointed from the mid-19th century, gathered evidence on a range of public health matters including the milk supply.  They inspected milking parlours, visited dairies, tracked the spread of disease and reported on the cause of deaths in their area.   All of which helped to persuade others of the need for improvements.  Some changes were slow to come.  Franz Ritter von Soxhlet (1848-1926) proposed a way destroying the harmful bugs in milk by heating it, i.e. pasteurization in 1886 but British diary farmers resisted compulsory pasteurization.  It wasn’t until 1949 that it became standard practice across the UK. 

This book by Hannah Velten provides more information about the history of milk.