(or how to put us out of business!)
There have been many small coffee roasters start-ups in recent years. Many of those doing the roasting “graduated” from home roasting to commercial roasting. There are many advantages to home roasting. You can have fresh roasted coffee all the time. You can roast coffee to light, medium, or dark or anything in between that suits you. You can buy a great many strains of Arabica beans from businesses that sell green beans to home roasters. Compare that amount of choice with the already stale coffee, from unknown sources, in grocery stores.
There are many home roasting machines for sale that you can choose from. Here are two methods of roasting coffee:
Drum roasting heats coffee beans that are inside a rotating drum. The drum has fins inside it that cause the beans to tumble as the drum turns.
Fluid roasting bounces the coffee beans on a column of hot air. Both methods keep turning the beans so that the beans roast evenly. Fluid roasters and drum roasters debate about which method is better.
Ideally your roaster provides you with lots of good information and functions: elapsed time of the roast; clear view of the roasting beans and their colour changes; the temperature of the beans (not just the space in which they are roasting); quiet operation so hearing first crack and second crack are clear; the suppression of smoke from the roast; the collection of chaff from the roast; rapid transition from roasting the beans to cooling the beans preventing beans from over roasting; a profile of the roast that is a record so you can improve your “recipe” for the particular beans you just roasted. There is no ideal roaster that provides all these advantages!
As a roaster you can keep good records to use in improving profiles and improving roasts. A bright LED flashlight often facilitates seeing the changing colour of the beans. A kitchen timer can count up the minutes and seconds of the roast. Some home roasters add thermometers to their roasters. Coffee roasting uses high temperatures and fire is a danger. Never leave a roast alone; for safety’s sake always stay with your machine. Eyes, ears, and nose provide information to the roaster. And the more information the roaster has the more he or she can improve and shape the roast. The roaster starting with high quality beans will quickly improve on the stale and bland coffees on the grocery store shelves. Your fresh roasts will be vastly superior to stale coffee.
As coffee roasts, the beans expand, lose weight and get lighter in colour until the beans reach their “yellow time”, the beans’ lightest colour. Then the colour changes to sand, then tan, then light brown, then darker shades of brown, to black in very dark roasts. At some point in the roast the beans go through first crack that sounds like popping popcorn. Water is exploding out of the beans in first crack. After first crack you have a drinkable coffee. It goes from a light roast to a medium roast and then in second crack a dark roast. Second crack is faster, quieter, and higher pitched than first crack. It sounds a bit like milk being poured on rice cereal. The farther the roast goes into second crack the darker the roast gets and beyond second crack the beans can catch fire. The darker the roast, the more diminished the flavours in the roasted beans. Many coffee connoisseurs prefer light and medium coffees for the sake of the flavours. However, if you prefer dark roasts, there are strains of green coffee that are best dark roasted and will give you rich, complex flavours. As a roaster you choose the roast levels that please you and the strains of green coffee that please you.
My knowledge of home roasting machines is out of date. To see the home roasters currently available go to Sweet Marias website www.sweetmarias.com and click on “roasting”. Before we go any further Home Coffee Roasting: Romance & Revival (revised edition) by Kenneth Davids is a must read. None of the home roasters he mentions are current; but, the explanation of the process is excellent background understanding needed to hone your roasting skills. You will learn what is happening in first crack and second crack and learn about roast levels.
We recommend that you start roasting with a popcorn air popper. Our first roaster was an air popper. The air popper you need has a popping chamber (or in our case a coffee roasting chamber) with a solid base and vents along the sides to agitate the coffee beans. See the photos below. Use as much green coffee as you would popcorn kernels -- trying to roast a lot is a mistake. You will find instructions online for roasting coffee this way. As with any online instructions, be wary of the quality of instruction which will vary from poor to excellent.
Initially the beans are heavy and a wooden spoon is helpful for agitating them to get an even roast. As the beans become drier and lighter during the roasting process, they will agitate well without being stirred. The wooden spoon is also useful to lift out a few beans several times during the roasting process to check the colour. Every popcorn popper is different and you need to figure out what works for you. The chaff from the roasting beans flies everywhere; but, in our roughly finished garage it is just a matter of sweeping up after the roast. If you roast inside you will need a way to exhaust smoke like a vent over a range.
Once the beans are roasted they need to be cooled quickly, or they continue to roast past the level you want. We use two large-screened colanders and a fan outside and pour the beans from one colander to the other in front of the fan to cool the beans. With this operation the chaff also flies away. If you have a stiff breeze you do not need a fan. However, the fan is more predictable.
From start to finish the roasting takes six to eight minutes and then you add the time for cooling the beans. The last time I checked in a large hardware store’s kitchen section I found a popcorn popper with the right kind of popping chamber for $20 Canadian. If you decide that coffee roasting is not for you your investment is small and you can still pop popcorn. There are roasters who install a thermometer in their popper and never advance to any other roaster. We recommend this simple, easily learned roasting method.
When you are seriously ready to buy a coffee roaster, check out RK Drums www.rkdrums.com that sells well-made hardware to convert a gas barbeque into a good coffee roaster. The equipment and online advice are both excellent. When we first went commercial we used a large RK Drums roaster. They have roasters from small to large. As an outside roaster in the Canadian winter it can be unpleasant.
From a repurposed popcorn popper to a repurposed barbeque to many dedicated home coffee roasters choose what works for you and learn to use it well. Then you are beyond stale store-bought coffee.