Wednesday, January 22, 2014

Coffee Roasting for fun and profit

By Donald Sensing

Well, roasting for fun, anyway. After a hiatus of several years, I am roasting my own coffee again. This is the first batch. It is from Papua New Guinea. I bought five pounds of the coffee "green," or unroasted. Green coffee has a shelf life of about two years. 

I have a coffee roasting machine that will roast about three ounces per batch. With two roasting chambers I can knock out six ounces in 20-30 minutes, depending on how dark I want to roast and what the ambient temperature is. 

Despite what people tend to think, roasting coffee does not smell so great. It is roasted coffee that smells good, and then not for several hours. And once you roast past medium brown, the coffee gives off smoke. So I roast outside, but last night because of the cold I roasted in the garage. 

This level of roast is called Full City. Coffee roasts the same way popcorn pops, except coffee beans do not explode, of course. My roaster is a hot air roaster. Hot air blows from the bottom of the chamber. As the beans heat, they expand and slough off a very thin layer of chaff. Then the moisture inside the beans vaporizes and pops. This is called the first crack. If you keep roasting there will be a second crack, which denotes the beginning of dark roast phases. The coffee in the pic was roasted until about midway through the second crack, then I set the roaster to cool air to stop the process. 

Once the fan stopped I quickly dumped the coffee into a colander. This helps it cool more quickly and sieves any chaff that the roaster's chaff screen didn't catch.

Roasted, unground coffee will lose half its flavor in two weeks. Once ground, it's half gone in two days. 

Roasted coffee should be kept in an airtight container and protected from direct light. Do not keep coffee in the refrigerator or freezer; coffee is highly hydrophilic and fridges are damp! Chilling or freezing does not make the flavor last longer, either, since roasted coffee has almost no moisture left so there's nothing really there to freeze.

This is my roaster, the Fresh Roast Plus 8. 

It is no longer offered for sale, having been superseded by the Fresh Roast SR500, which I may get since it offers much more control and flexibility for the roast.

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