Milk adulteration - a question for the scientists amongst us

[John_Hartley]

I'm currently undertaking some general research with the local Stockport papers from the time of the war. It seems to be a fairly regular occurance of dairy farmers finding themselves in court for thinning down milk with water, often by around 10%.

I appreciate that customers are likely to think its been thinned from the taste but my question for the scientists is what tests would the local council staff have had available to them to prove the case in court?

[Malcolm]

Changes in freezing point or refraction of light from the whey. Probably the former in 1914-18.

Aye

Malcolm

[tintin1689]

"Little drops of water,

Little grains of sand,

make the milkman wealthy

and the grocer grand"

Weights and Measures Inspectors were (are?)trained to perform a comparatively simple test to ascertain how much water is in beer and milk

Regretably I don't know what it is, and probably would n't understand it if I did

Along with checking vendors scales and measures against standard weights and measures this was a big part of their work in those days. (I only know about this as I have an interest in Police history and in many places this was a police task)

[centurion]

Changes in freezing point or refraction of light from the whey. Probably the former in 1914-18.

Aye

Malcolm

Refraction techniques were first introduced by the State of Massachusetts in 1904 for checking milk. Freezing based checks do not appear to have been common until the 1950s. However the Formalin and Sulphuric acid check. was a likely method. Formalin was added to a sample which was then agitated. and a drop of Sulphuric Acid applied. If the sample turned blue then the milk had been watered.

New Zealand had a milk watering scandal in 1918 and a number of producers were prosecuted.

[truthergw]

Would watering milk affect its specific gravity?

[centurion]

Simple testing could be initially carried out using a a lactometer also known as a galactometer. This is a specialised form of hydrometer for milk. It isn't 100% effective as milk can vary in density for many perfectly innocent reasons but it acts like the blow in the bag breathalyser - if you get the wrong reading then you go on to more precise testing such as those mentioned above. I have seen them used on dairy farms, that bottled and distributed their own milk, for random checks. (My uncle was such a farmer)

[keithfazzani]

The standard method in use then was the Gerber method, largely replaced in the latter part of the 20th century for routine testing by cryoscopy or measuring the depression in the freezing point of the milk. Details of the gerber method Gerber Method

[centurion]

The standard method in use then was the Gerber method, largely replaced in the latter part of the 20th century for routine testing by cryoscopy or measuring the depression in the freezing point of the milk. Details of the gerber method Gerber Method

The Gerber method is not a test for watered milk. It is a method for analysing the fat content of any particular sample of milk. Without a standard of what the fat content should be it does not tell you if that sample has been watered. Milk from different herds will have differences in fat content depending upon the breed of cow, average age of cow, what they have been fed on, the time of year etc etc.

[Magnumbellum]

"Little drops of water,

Little grains of sand,

make the milkman wealthy

and the grocer grand."

Another comment from the period and earlier was to refer to milk having come from the "iron cow", meaning the farmyard water pump. As late as WW2 there were some milk producers still delivering milk by drawing it direct from a milk churn brought to the doorstep and pouring it into the householder's own jug, with suspicions that the churn had been diluted.

The "grains of sand" in the doggerel refer to the dilution of sugar at the time it was weighed out for each customer from a sack which might or might not have been adulterated. I know of know no specific case of that happening at a grocer's, but it certainly happened in the case of sugar bowls in a certain cafe in the 1920s.

[auchonvillerssomme]

Put your search request into HANSARD http://hansard.millbanksystems.com/search plenty of info there.