Bob's Cheese and Wine Blog

My world of cheese and wine

Archive for December, 2010

Rennet

Posted by fromagebob on December 26, 2010

Rennet is the generic name for the family of enzymes used to coagulate milk in the cheesemaking process. Rennet is derived from one of three sources: Animal, microbial, or vegetable. All introduce similar action in the milk; the enzyme causes a chemical reaction that separates the milk proteins, separating the milk into curd and whey. Once the initial action of the enzyme is completed, the traces of the enzyme remaining in the milk play a role in the aging process, and the creation of various aromatic and flavor profiles.

Animal rennet is derived from the fourth stomach (abomasa) of an unweaned ruminant. The stomachs are dried and either powdered, or cut into pieces for later use. The enzymes found in animal rennet are chymosin (80%) and pepsin. The young animal uses the enzymes to coagulate the milk in the stomach for better digestion.

There is no clear indication of when cheesemaking started; the earliest evidence dates back about 5,000 years, but it is very likely that the use of milk as a nutritional component extends much farther back in time, to the period when man moved from a hunter-gatherer (nature-provided) form of food generation to an agricultural / pastoral form.  Evidence of herding dates back some 30,000 – 40,000 years, so it is likely that the use of milk in the diet extends back almost as far.

Milk, when left to sour, naturally separates into solid and liquid, as the acid level of the milk increases. Given that the origins of man place us in the Middle East, and that the climate there was quite arid, it is likely that the souring of milk, and the use of the liquid and solid was common. It is not much of a stretch to imagine man figuring out that draining the liquid extended the life of the solid material, and then to using some form of pressure to force more liquid out.

When rennet came to be used as a coagulant is not known. The popular “creation myth” for rennet is that of a nomad galloping across the desert, his milk ration hanging from the saddle in a stomach being used as a container. Although that has a nice, romantic “ah-ha!” feel, it is far more likely that the discovery of rennet’s coagulating properties was a mundane accident. Given that early man would have made use of all of the parts of the animal, cooking stomach (tripe) in milk is the more likely source of the discovery. It is likely that the realization that combining milk and stomach took some time, as it had to be the perfect storm of events: the correct stomach, in milk, at the (reasonably) correct temperature. Speculation would say that the use of rennet as a coagulant probably occurred over several thousand years. I checked on-line for recipes using tripe and milk, and found quite a few. Here’s one from Gordon Ramsey…

In addition to coagulating the milk, rennet also plays an important part in the development of the flavor of the cheese. The biggest difference in the impact of rennet on flavor is found in cheeses made from thistle, or Cardoon, rennet, especially those from Portugal. Thistle-rennet cheeses often have more pronounced vegetal aromas and flavors, and are not as prone to the “piquant” or peppery feel of animal or microbial rennet cheeses.

When looking at the ingredients list of cheese, it is sometimes difficult to discern which rennet was used in the making of the cheese. For vegetarians, this is an important consideration. The obvious labeling shows the cheese as being vegetarian, but if that is not included, you must look at the ingredients list. Clues are “microbial rennet”, “vegetable rennet”, and “thistle rennet.” If the labeling is “animal rennet or “traditional rennet” then animal rennet was used. The problem comes in when the labeling simply says “enzymes” with no reference to the type used. Some manufacturers will include “no animal rennet used” on the label, but for others, you would have to contact the cheesemaker directly.

Cheeses made in Europe use mainly animal rennet, while cheeses made in the US use mainly microbial. Most Portuguese cheeses are made with vegetable rennet.

Sources for information in this article: American Farmstead Cheese, by Paul Kindstedt, Brined Cheeses, by A.Y. Tamime, and The Wisconsin Center for  Dairy Research publication, Dairy Pipeline, October 2000, Volume 12, Number 3.

Advertisements

Posted in Cheese Basics, Cheese Education | Tagged: , , | 1 Comment »

A History of the World in 6 Glasses

Posted by fromagebob on December 9, 2010

Start a discussion about history, and you’ll be mining a rich topic that runs the gamut of the human experience: battles and conquests, migration and survival, kings, queens, religion – you name it. One topic you probably won’t touch on, though, is beer. Or wine, coffee, tea, spirits, or Coke, for that matter.

It turns out that those six beverages (or at least the first four), had a huge impact on our survival and the development of our civilization. “A History of the World in 6 Glasses” by Tom Standage, is a great look at how beverages that we take for granted today were at the foundation of our development as a people. Beer and wine were accidental discoveries that provided the basis for early survival. Coffee took the place of beer as the morning beverage of choice, and tea laid the foundation for the English empire. But all of them played a fundamental role in the story of us, and how we became who and what we are today.

As we moved from hunter-gatherer to more urbanized settlements, one of the big problems became the disposal of waste and the subsequent contamination of water supplies. When you’re hiking through the jungle, any stream will do to quench your thirst, but as the population became more urban, drinking downstream from the neighbor created some real issues.

Beer was one of the earliest non-water beverages that was safer to drink than water. The fermentation process, and the alcohol content, negated the contamination that was very common in the population. Plus, it contributed to the nutritional well-being of the imbiber, which helped to improve general health. Wine also became an important beverage for the same reason – it was safer than water, and also provided benefits to the drinker in the form of polyphenols, anti-oxidants, and more.

The more fascinating of the four were coffee and tea. Because beer and wine were safer than water, and because they were fairly easy to produce, they were the drink of choice for a very long time- up until the late 16th century in Europe. Coffee originated in the Middle East, and became a fairly common drink in the 15th century. Up until that time, it was very common to start the day with a watered-down glass of beer, and to imbibe beer or wine as a beverage throughout the day.

Coffee changed that; as it became popular in Europe – especially in England, coffeehouses began to appear, and became the center of science, finance, and industry in a fairly short period of time. The reason (as we know today) was simple – a cup of coffee is stimulating, where a glass of beer is not. Men began to congregate in coffee houses to discuss business and the news of the day; coffee houses began to specialize in a particular area of knowledge, such as finance, marine affairs, science, and so on. Lloyds of London started in Edward Lloyd’s coffee house. The London Stock Exchange started in Jonathan’s Coffee House on Exchange Alley. In France, Joseph Priestly (“The Invention of Air”) met Benjamin Franklin and other notable scientists and philosophers in a coffee house.

Because coffee was made from boiled water, it was safer to drink than plain water, and because it stimulated rather than sedated, it became the drink of choice of business men and the intelligentsia alike.

Tea also played an important role in the rise of civilization and the foundation of our country; like coffee, it was safer to drink than water, and like coffee, it provided stimulation from its caffeine content. Tea played a large economic role in the rise of England to power, because it was such a valuable commodity. In the cities, women were not permitted in coffee shops; their venue of choice became the tea parlor, and the custom of afternoon tea became quite common. As the production of tea became more widespread, the cost came down, and it became the beverage of the workingman in England.

This is a great book for anyone interested in the minutia of history – of those things and events that played an important role in the rise of man, and the development of civilization. We tend to think of history as a grand movement from level to level, but – as this book aptly shows – history is more of a series of accidents and opportunities, from which greatness may (or may not) arise.

Best part of the book for me was finding out the truth about Coca Cola! Read it for yourself, and see.

Posted in Book Review, Wine and Cheese History | Tagged: , , , | 2 Comments »