Right then, let’s start from the very basics.
The vast majority of cows milk that we buy and consume in the developed world has gone through two pretty major scientific processes: pasteurization and homogenization.
Pasteurization is done for fairly obvious reasons. Unpasteurized milk does taste a lot better (and has an odd yellowy colour), but unless you live right next to a farm, know a bit about the cows that are producing it, and aren’t going to keep it for long, then it’s probably not the best idea to buy and use it.
Homogenization on the other hand gives no health and few storage benefits. It’s only purposes are aesthetic, and to give the product a slightly longer shelf life, and the fact that you don’t need to shake the bottle to mix the cream. It’s a complex process but the simplest explanation is that the fat particles in the milk are broken down into a smaller size (from 2-4 microns to 0.4 microns) so that the milk looks smooth and has no lumps of cream in it.
I buy unhomogenized milk whenever I can for a number of reasons, which we’ll go into in a minute, but it can be a bit trickier to lay your hands on than homogenized is. When I was living in the UK, I could always get it in the Waitrose supermarket chain, and here in Barcelona I buy it from the local cheese shop. If you can’t find it in a supermarket then you might want to try a farmers market or a cheese shop.
You should buy it because…
So, after hunting it down, what do I get by buying unhomogenized milk?
I get the kind of milk that I remember as a kid. Unhomogenized milk has that cream line at the top, so that everyone (who likes milk) wants to the one who gets to open the next bottle or carton and get the lovely fatty creamy bit.
In the US, homogenized milk has been the standard since the 1930′s and it has spread over time to cover pretty much every developed nation on the planet. The UK was one of the longest holdouts, only making the change en masse to homogenized a few decades ago. When the majority of British milk came from the milkman then it was all unhomogenized, but when we gave up that great institution and started buying it in the supermarket, then we didn’t only change the delivery method but also made a switch to homogenization.
Apart from the creaminess and the nostalgia of it, there are a number of other reasons why I prefer unhomogenized milk.
A lot of people believe that there are health benefits associated with unhomogenized milk. There is some evidence that implies that homogenized milk may be more likely to trigger allergies, but I am not aware of any large scale study of this.
Various studies have shown that homogenized milk may be bad for you for a number of different reasons. One of them links the rise in heart disease in the years following 1932 to the invention of the homogenization process. Dr. Kurt Oster has spent decades trying to prove that homogenized milk has links to all kinds of different disorders, including atherosclerosis, but the fact is that the majority of these links are not widely supported by the scientific community and there is not a large amount of evidence for them.
Whilst none of this evidence is particularly strong, you do have to wonder why we would want to pass any foodstuff through an additional mechanical process that gives absolutely no real benefits, and certainly no health benefits, but may have several negative health effects.
One useful fact in the kitchen, is that because of the bigger fat molecules, unhomogenized cream takes about half of the time to whip that homogenized cream does.
Apart from anything else though, and most important of all, is the fact that unhomogenized milk and cream simply tastes better!