You will need these
Find an open place with electrical outlets nearby. Roasting is a rather noisy, smelly and messy affair. The heat gun or popper puts out quite a roar, the smoke is *not* the essence of brewed coffee, and the chaff will fly. I use the garage because a little more debris here and there is no big deal.
If you are using a heat gun and dog bowl, make sure the surface that the bowl is resting on is either well protected or heat resistant. That bowl is going to be ~430F and if those little woody beans are smokin’ so will your nice black walnut side table. Brother Nathan does his thing on the BBQ, while I have a bit of cardboard under my bowl.
If you are using a popper, you might consider placing a bowl in front to capture the chaff. It is not necessary but it makes cleanup much easier. If you are using a heat gun, I hope you don’t mind sweeping.
Think ahead of time how you are going to cool these especially hot beans when they reach the desired roast level. I used to dump them into a colander and swirl them around before spreading them on a cookie sheet. Now I use a winnowing tray that would be used to separate chaff from rice, and toss it around a bit. Nathan uses a screen mounted on a frame on top of a box fan that has been laid on it’s side. That girl is cooler than anything else I’ve seen. I have heard that some folk keep a little spray bottle handy to mist the beans right when they come off the roast, to just stop the roasting.
Alright, putting the right amount of beans in the popper is pretty easy. Just keep adding beans until it *almost* stops spinning the beans. It is usually around 1/2 cup, but may vary depending on the beans. Tt is a little harder with the dog bowl. How long do you want to be holding that heat gun and stirring those beans? How much do you want to loose over the side? I would start small, maybe filling the bowl 2/5 of the way (less than half) and see how that goes first. Of course, if you bought yourself one of those huge dog bowls, you might want to consider returning it before you lacquer it up too much with coffee residue after learning that your arm just can’t take that much stirring. My little bowl takes 1 1/2 cups just fine, but I have a friend that routinely roasts 3+ cups in his old mixing bowl. He also stirs the beans with the heat gun and likes a very dark roast.
If you are using a dog bowl, you will need something to stir the beans with to make sure they are heated (more) evenly. I use a wooden spoon. You will be stirring constantly for the next 15-30 minutes, so make sure you are comfortable and you used the restroom. The first few times you roast with the heat gun and dog bowl your arm(s) will hurt like heck 5-10 minutes in. Later, after you get used to it, it won’t start hurting until the 15-20 mark. Eventually you will be an Olympian roaster and you arm will not hurt until you have done 3-5 rounds in a row. Keep in mind that unless you have set up a rig to hold the heat gun, you will have it in one hand while you stir with the other. It takes real constitution and perseverance to make it to the Olympian stage.
The beans will start loosing chaff almost right away, but it will really get going once they start to heat up. signs of roast that you are looking for are color change, smoke, and sound. The color of the beans will go from green to yellow to light brown and then just darken from there. Roasted beans will always be some shade of brown when they are done, and will never be yellow or green. OK, maybe that is obvious, but I just thought I would make sure.
First crack usually comes as the beans turn brown and will be a sometimes sharp snap. You will usually hear a few and then more. When there is a constant snapping sound, that is called a rolling first crack. Usually, but not always, the snaps will die down and the beans will continue to darken. Then you will begin hearing second crack. This is distinguished from first crack because the sound is a higher pitch, more like a tic. Smoke often accompanies second crack. If you continue roasting and you stop hearing signs of second crack, you have just ruined your coffee. Well, maybe you like French roast, but if you do, don’t bother buying any special coffee because French roast completely obscures the regional flavors.
So, how do you know when it is done? Here are some terms:
- City – The signs of first crack have ended, the beans are a little browner, but there is no sign of second crack yet. This would be considered a medium-light roast.
- City+ – Just a little bit longer than City, the beans are darker but still no sign of second crack. The beans are mostly medium brown and may still have some chaff clinging to them.
- Full City – You hear the first signs of second crack and you stop the roast. The beans are medium to dark brown, but free of oil.
- Full City+ – You hear about 10 seconds of second crack and then stop. The beans are a dark brown and some oils may be visible.
- Vienna – You wade those beans hip deep in a rolling second crack. Oils are obvious on the beans.
- French – Second crack is over, and the beans are black and slick. Lots of smoke.
- You have gone way to far – Smoke is billowing up, the beans a sizzling. You can’t drink this.
The first and most important thing to do once you reach the desired roast level, is to stop the roast. If you don’t, the roasting will continue, just from the collective heat of the beans. The fastest way to stop the roast is to dump the beans into something where the cooler air of the room flows through the beans. I dump the beans into my winnowing tray and start tossing them around. With every toss, the air flows around the beans and cools them. If you have a box fan, an old screen and a deep frame, you could build yourself a very nice cooling tray that will bring the beans out of roast, and into storage temp within 30 seconds.
The the beans rest after they have cooled. Not all of the gases have escaped from the beans, so they need some time to breath. This will depend on the roast level and the bean. Some are ready to grind within several hours, while others don’t bloom for 5 days or so. I generally try to let all my beans rest for a day or two before I use them. I keep my beans in canning jars, but leave the lids loose until the smell of the beans strikes me as “ready”. Then I tighten them down and keep them sealed until use.
Different coffees will roast at different speeds, and will be better a different roast levels. I like taking the dry processed Ethiopian coffees to a City- (barely out of first crack) because at that point they have tons of their fruity flavors. Brazilian beans are often good at a Full City+ to get their chocolaty fullness. Experiment!
Sometimes you will see that the roast is uneven. My policy is that unless the flavor is bad, I won’t pick out any beans after the roast. In some cases, like the Ethiopian coffees, I want all the odd light colored beans because they contribute to the fruity flavors. An uneven roast will sometimes add complexity, as the lighter beans will produce more regional flavors, and the darker, more caramelized beans will add fullness and sweetness.
Some coffees that are known for their fruity flavor need to rest longer. Ethiopian Harrar, known for it’s blueberry bomb, takes a light roast, and then needs 5+ days to rest. The Ethiopian Sidamo that I roasted recently had a similar blueberry flavor, but it was evident after one day.