Okay, “processing” is an ugly word. It makes me think of factories, and chemicals, and other icky things. But that’s the word that we use to describe what happens to milk after it leaves the cow and before it gets to you.
And no matter what you call it, it is really important.
In my last post, we talked about all the things that milk is tested for before it is unloaded at the processor. Here’s what happens, after the milk passes all its’ final exams.
Milk in the grocery stores is pasteurized and homogenized. You’ll see these two words used together all the time, but they are two separate processes.
Pasteurization is basically a form of sterilization. The milk is heated to very high temperatures for a short period of time to kill any bacteria that are normally present in raw milk. Depending on the type of pasteurizer the processor uses, the milk is either heated to 145 degrees Fahrenheit for 30 seconds or to 161 degrees Fahrenheit for 15 seconds. Then the milk is rapidly cooled back down to prevent any new bacteria from contaminating it.
Homogenization is a fancy word that basically means “mix up really well.” If you leave raw milk alone, the cream will separate to the top of the milk. No doubt you’ve noticed that this doesn’t happen to the gallon of 2% milk you have in your refrigerator. That’s because the milk was homogenized – the milk fat (what makes the cream) is broken up into microscopic-sized particles so it is evenly distributed throughout the milk and can not come together and rise to the top. In addition to making milk that looks nicer and doesn’t need a vigorous shaking to drink, it also makes it easier to digest.
Some of the milk fat is removed to make the different percentages of milk that you find at the grocery store. Raw milk has over 7% milk fat, depending on the type of cow and their diet. Whole milk is only 3.25% fat, and skim milk is fat-free.
When the milk fat is removed from the milk to make these lower percentages, some of the vitamins A and D are also removed. (These vitamins are fat-soluble, and stick to the milk fat.) That’s why most milks you find are fortified – this simply means that vitamins A and D have been added back into the milk after the fat content was reduced.
Milk, in any form, is an excellent source of calcium, protein, and vitamins. In fact, it has more electrolytes than many sports drinks! However you like your milk – whole, 1%, strawberry, or chocolate – it really is a “super food”!
And remember – it only takes two days for the milk to get from the cow to your grocery store. If that’s not fresh food, I don’t know what is!
I actually just visited a dairy a few days ago. That dairy used something called Low-Temperature Vat Pasteurization. The dairy claims the low temperature keeps more of the good stuff in milk.
They also choose not to homogenize, they claim homogenizing breaks up some proteins that make milk easier to digest. Homogenize or not to homogenize, that is the question.
(I originally visited to learn about making ice cream)
Here’s a link:
http://www.thesocialsilo.com/2012/07/31/national-ice-cream-month-how-to-make-ice-cream/
Will, thanks for the link, I enjoyed your story! There is some evidence that “regular” pasteurization does destroy some of the natural enzymes in milk. This makes sense, because enzymes (which are a special kind of protein) are destroyed by heat. It was my understanding that homogenization actually makes the milk easier to digest, but I am sure there are differences in opinion on this as well! The bottom line is, milk = good; ice cream = great, however you choose to make it! Yum!