Oldcoffee

Why Doesn't Coffee Last Forever?
(or, darn, are our tires bald again?)

Unlike tires, which probably could be made to last forever, coffee has an inherent problem. . . if one wants to drink it, it must age.

To start at the beginning, green coffee beans are roasted, much like peanuts or popcorn. The beans are placed, at the Coffee Exchange, into a roaster with an internal rotating drum, much like a clothes dryer. They are gradually heated to a temperature of about 430 degrees or so, depending upon how dark a roast is being done. During this process many chemical changes take place. One of these changes is the formation of carbon dioxide within the cell structure of the coffee bean. There are literally thousands of cells within a coffee bean. Within each of these cells, carbon dioxide is produced as a natural result of exposing the bean to heat. The carbon dioxide produced is at about 20 atmospheres pressure within the bean.

Carbon dioxide is an anti-oxidant. That is, it will not support oxidation.

Over time, the carbon dioxide leaves the coffee bean in a process known as de-gassing. Once the carbon dioxide has gone from the bean, the bean is much like a sponge, and oxygen is free to enter the cell structure. Once oxygen is in contact with the oils in the bean, the aging process begins, and the oils begin to go rancid. All that is left is for you to notice a "funny taste to the coffee".

This, of course, prompts one to ask "How can I keep these tires from going bald?" This is an easy question to ask, and almost as easy to answer, once the process of aging is understood. Simply place your coffee beans in an airtight jar, and don't open it. Of course, you might notice the problem encountered using this method . . . ya' can't drink the coffee! So, let's look at how you can preserve the beans. Click on PRESERVE

Last updated Saturday, April 05, 2008