Saturday, December 07, 2013

Cheese in detail

It's Saturday night, and I'm reading an article that contains far more detail about the chemistry and biology of cheese than I really need to know, including this:
In Quicke’s vat, this arrangement has broken down and become curds and whey, on its way to cheddar. If milk is left alone, bacteria quickly start converting its lactose sugar into lactic acid that can eventually start this curdling. This is probably how cheese was first made, but modern needs for safe storage and maturing demand a different approach. Quicke’s minimally pasteurises its milk, and like most modern cheesemakers adds a starter culture including lactic acid bacteria such as Streptococcus, Lactococcus and Lactobacillus. They work hand-in-hand to control which bacteria reach the final cheese, by outcompeting less welcome species and making the environment too acidic for them. And rather than these bacteria doing the curdling, acid conditions help an enzyme preparation known as rennet to do it. Their ongoing acidity development also controls the resulting solid curd’s texture.

Traditional rennet, which Quicke’s uses, comes from soaking a milk-fed calf’s stomach in brine.
 Had some nice goats cheese at dinner tonight, as it happens.

UPDATE:   I was wondering last night how someone first worked out that calf's stomach contained something that was useful in making cheese.  Another site provides the likely answer:
There is a great deal of mythology surrounding the history of cheesemaking, because humans have been making it for a very long time, and the steps involved are actually fairly complicated. The stomachs of ruminants have historically been used to make bags and sacks, and food historians theorize that someone must have stored milk in one a bit too long, allowing it to curdle, and the curdled milk was then turned into a food product. Modern rennet is created through an extraction process that yields neat, dry tablets or a liquid that is very easy to work with.

 Traditional rennet was made by washing the stomach of a young ruminant after it has been slaughtered, and then salting it. The salted stomach is kept in dried form, with cooks snipping off small pieces and soaking them in water when they have a need for the extract. Some cheesemakers continue to make and use it in this way, but the vast majority use commercially processed rennet, which is made by creating a slurry and then subjecting it to a compound that will cause the enzymes to precipitate out.


John said...


Something myself and a friend have been looking at is source of Vitamin K2, and some cheeses are good sources of it. Vitamin K1 and more particularly K2 are very important for calcium regulation. Vitamin D is not enough, in fact Vitamin D+calcium-vitamin K appears to induce tissue calcification, a major risk factor for cardiovascular diseases See:

Steve said...

I see from that link that K2 is found in lots of things pleasant to eat, although highest in the very stinky natto from Japan.

I wonder if one can learn to like natto - from my age, it sounds like a good thing to try for its possible prostate benefits alone.

John said...

I know, I got some natto but can't stand it! A friend of mine has looked extensively into this issue Steve and while K2 is the better option some cheeses contain it in good quantities. Additionally it seems to me that if we maintain sufficiently good K1 intake that will be adequate; though I am in a very small minority in that regard and I don't read that much on nutrition.