Raw milk or pasteurised?
Raw milk is available from some healthfood stores in South East Queensland. It’s a farm to consumer product sold in standard 2 litre disposable bottles and labelled as “Bath Milk, not for human consumption”. It’s a rich milk from Jersey or Guernsey cows and has a high cream content.
Milk is valued by its butterfat content, which is the key nutrient.
Raw milk producers must maintain scrupulous hygiene in the dairy with high health standards for their milking herd. One pleasing fact about this unpasteurised milk is its shelf life. It generally stays usable for a good 5 days longer than normal pasteurised milk.
Why is that?
I once lived in Belgium and ran the mix in an icecream factory in the industrial northern suburbs of Brussells. My employer and mentor Charles was a good Frenchman with a degree in milk chemistry from a university in Switzerland.
Charles explained to me that raw milk had a “bacteriostatic factor”. If a bowl of fresh raw milk is put on the kitchen bench it will not begin to “turn” until 24 hours have passed (the way milk ‘turns’ is the basis of cheese making).
If chilled when fresh the milk retains this bacteriostatic factor, which is denatured by the heat of pasteurisation.
Until the early 1990’s there were many raw milk dairies in Australia, for example micro dairies providing fresh goat milk, however they were forced to close when legislation required that all milk for human consumption be pasteurised, an industrial level process beyond the resources of small producers.
Raw milk sales are banned in most of the developed world, all milk must be pasteurised, a heat treatment to kill microbes. The pasteuriser is a continuous flow heat exchanger with hot water on one side and milk on the other, the milk must be heated quickly to the required temperature of around 71 deg C for a limited time (about 15 seconds) then rapidly cooled by chilling. An important factor deciding these temperatures and times is the microbial count of each batch of milk.
Pasteurisation allows dairies to supply milk to factories with a higher microbe count. I know for a fact that a dairy factory in Victoria used to deal with batches of souring milk by adding sufficient caustic soda to normalise the acidity then run the batch through the pasteuriser. One excellent small dairy in the Sunshine Coast hinterland will reject a batch of milk if the microbial count is excessive rather than increase the pasteurisation temperature to suit the batch. I’ve noticed that this dairy’s milk tends to stay fresher for longer.
Our immune system should recognize microbes but it isn’t good at recognizing the intestinal contents of killed microbes, a factor in allergic reactions to milk.
Homogenisation breaks up the fat in milk by sudden pressure which smashes the droplets making them small enough to stay in suspension. Because this prevents the fat from rising it’s impossible to know how much cream the milk really has – the cream may be separated out to go into other butterfat products and the milk thickened with milk powder to restore the flavour. Another problem with these microfined fats is that they may elude proper digestion and when absorbed cause immune disturbances or even lodge in crevices such as behind heart valves to attract microbial or inflammatory problems. Fortunately, non-homogenised milk is readily available.
Traditionally, when nomadic peoples began to acquire herds, the milk was a valuable nutritional supplement and preserved by culturing to make curds and cheeses. Eating butter, yogurts and cheeses is preferable to drinking milk. Homemade kefir from milk kefir grains is a remarkably nourishing food and probiotic.
Milk and milk products are embedded in our dietary culture such that persons who avoid dairy have created a market for milk substitutes. These substitutes are not foods and to be enjoyed in very limited amounts.
Support local dairies as much as possible. Enjoy the great range of quality products available to us, they’re a sign and source of food richness in our country.
Until next time, keep safe and be well,
Hugh Wallace Naturopath