I’m proud to introduce Doug, my wonderful brother-in-law, who so graciously wrote this post on how to roast your own coffee beans. I’ve been the lucky recipient of his delicious home-roasted coffee beans and can fully attest to their yumminess.

So, take full advantage of this once- in-a-lifetime divulging of coffee-roasting secrets. Go forth and roast beans to your hearts content. Thinking of calling my personal barista Doug to roast them for you?

Fuggitaboutit. Get your own brother-in-law.
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Greetings! Jennifer asked some months ago if I would be interested in blogging about coffee. This was not just some random request on her part – in addition to being an avid (rabid?) consumer of espresso, I also roast my own coffee beans. So I agreed to share my thoughts and musings about this albeit low-thrill hobby on this forum.

Background

My wife, Laurie (Jennifer’s youngest sister) gave me an espresso maker as a surprise Christmas gift in 2005. Prior to that time, I regularly consumed one or more small espresso drinks (either a cappuccino or latte) a day. I found the milk rather filling, so I began drinking plain espresso. Hence, the idea for my gift…

It is no secret that the main “supplier” of my desired beverage was Starbucks – partly because of the flavor, but mostly due to the close proximity of a location next to my office. They produce a beverage of consistent flavor and quality. To this day, I still frequent this chain whenever I am away from home and require a “fix.”

Those of you who enjoy the robust flavor of espresso my have noticed that the Starbucks variety, while flavorful and consistent, has a carbonized (or almost burned) taste. This is due to the roast characteristics (more about that in a minute), which works especially well for milk-containing drinks – cappuccinos, lattes, macchiatos, mochas, etc. My own informal sampling – which consists of nothing more scientific than noting the types of drinks ordered while I am waiting my turn in line – reveals that the vast majority of beverages made with espresso contain milk.

Around this time, the husband of one of Laurie’s law school classmates asked if I had ever tasted “really” fresh-roasted coffee. I said “well, sure I have, hasn’t everybody?” “No” he replied, adding “most of the coffee that you drink was more than likely roasted weeks or even months ago.” I conceded that I honestly didn’t know, but had no reason to doubt him. He said “Unless you have ever roasted your own coffee, you have probably never tasted fresh-roasted coffee.” He then proceeded to explain to me how he roasted his own coffee at home, where he obtained green (unroasted) coffee beans, and how he built his own roaster.

The fact that he was a physics professor at the time at Georgia Tech and my own background in chemical engineering made me feel like we were relating on a scientific level. Or perhaps it was nothing more than the fact that we were both hyper-caffeinated at the time. Regardless, I immediately became interested in exploring this idea.

First, I had to build my own roaster. You can buy any number of quality home-sized coffee roasters – but the idea of “building” my own appealed to the engineer in me. OK, I really didn’t have to build much – a home-made roaster is nothing more than an old hot-air popcorn popper with a thermometer added to it! Notice that I said “old” popper – the wattage on the newer models, while safer for home use, do not come close to the 1400 to 1500 watts necessary to produce a quality roast.

Unless you happen to have an old hot-air popcorn popper lying about the house (I did not), you will have to search Ebay or your local thrift stores. The holy grail for home-roasters is the West Bend Poppery (Not the Poppery II). Other brands will also suffice – just be sure to select a model with the desired wattage. I was able to find a used Poppery in great condition for under $15 on eBay.

Next you will need a good thermometer, one that accurately registers up to 460 – 470 degrees F. I found a good thermocouple on-line for $30ish, which works very well. With a popper and a temperature gauge, you are now ready to roast – oops! – forgot the beans.

You will need to find some green coffee – I use Sweet Marias (www.sweetmarias.com) as my source. They source beans from all over the world, and offer a brief description of the flavor and roast tolerance for each variety that they sell. This site also offers great information for the do-it-yourself enthusiast, as well as offering related products (e.g. roasters) for sale.

Roasting

Before plugging in the apparatus and charring my first batch of beans, I read several different articles on home-roasting. I learned that the first “crack” (chemical reactions within the bean resulting a loud audible popping noise, not unlike the cracking process in petroleum refining) should/will occur in the 400 – 410 degree F range. The second “crack” occurs in the 450 – 460 degree F range. For espresso, darker roasts typically provide the best outcome.

Degree of Roast

As the beans are heated they pass through several different stages, marked by ever-darkening coloration of the beans. At the conclusion of the first crack, the beans are at the city roast level, and are sufficiently dark enough to brew coffee. The progression of roast stages is as follows: City, City+, Full City, Full City+, Vienna, French, Charred (burned to a crisp). Espresso is usually prepared with Vienna- or French-roasted beans, but Full City+ will also produce a nice shot.

If you try this at home, please follow this one piece of advice – DO NOT ATTEMPT TO ROAST THE BEANS INDOORS – the amount of smoke and chaff will not endear you to any loved ones or pets – unless, of course, you feel the urge to test your home fire alarm. However, if you do begin your own roasting experiments, try stopping at the various degrees of roast (several on-line sites provide temperature ranges for each) – you might be surprised at what tastes best to you.

Measure out 4 to 5 oz of green beans (I use 4 ½ oz) to roast – any type of kitchen scale should work. One last item that you will need (in addition to oven mitts) is a metal colander or sieve for cooling the beans after the roast (I use a large metal perforated pizza pan with a plastic backing tray). Once you have all of these items, and have a suitable outdoor location, you are ready to roast.

The First Roast

Set up the popper on a table or stand, and connect the power cord. Pour in the beans, and replace the top to the popper. Position the thermometer so that the end is at or slightly above the pile of beans. Now turn on the power – and begin waiting. It will take anywhere from 5 – 10 minutes to hear the first crack, depending on the roaster and the ambient air temperature. After the first crack subsides, several more minutes will elapse before you begin to hear the much fainter (and quicker) sounds of the second crack. Stopping a few seconds after this point yields a Full City+ roast; I typically go 30 seconds to a minute or so after the second crack begins for a Vienna roast.

If you continue the roast much longer, you will notice that the beans have become oily and appear very dark and shiny, which is indicative of French-roasted beans. Should you continue roasting past this point until the beans no longer appear oily, you will have succeeded in carbonizing the roast.

Flavor Characteristics

There are two main determining attributes to the flavor of coffee: 1) the origin of the beans (variety, location, and climate), and 2) the degree of roast. The darkest roasts “cook” away any flavor imparted by the beans, and leave only the degree of roast as the main flavor attribute. For my espresso, I prefer a Full City+ or a light Vienna, and typically I will roast one batch to a Full City+ and a second to a Vienna, and then combine both batches.

I have ordered beans from many locations around the world, and would be hard-pressed to name only one favorite. However, if I could have only two sources, I would pick a variety from Yemen, and a variety from Sumatra. To my taste, the Yemen beans have chocolate, dark, spicy flavors while the Sumatra has more of an earthy appeal. Also, the Sumatra beans become much more complex at darker roast levels. A close third for me would have to be the Brazilians…

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If you have any questions for Doug- post them here and I will make sure he gets them.

In the mean time- wouldn’t these be great gifts for Christmas? Think about it- a great mug and a bag of home roasted coffee beans.

This entry was posted on Tuesday, November 10th, 2009 at 8:00 am and is filed under all, cucina, daily diva. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.