What You Need: Whirley-Pop (previously known as the Felknor Theatre II) or Back to Basics Stainless Steel popper, or another similarly designed device, gas stove (electric with larger burner OK too), thermometer is mandatory for this method, a metal colander or two for cooling, and oven mitt. Stovetop roasting takes some practice. There are more variables than other methods since you set the heat and provide the agitation. But the results can be outstanding and the 1/2 lb. batch is nice. It sometimes seems like a 3-handed act: before you start, try a dry-run by adding green coffee without any heat, and agitate it. In the course of the roast, agitation gets easier as the coffee loses weight and expands.
Instructions:
- Turn on your stovetop exhaust fan, or open a kitchen window. Have all your supplies within reach.
- Measure out about 8-9 ounces of coffee by weight, or about 12 ounces by volume.
- Use a low flame / medium electric burner setting. NEVER use highest heat settings/flame -you'll scorch the coffee! See the tip below about using a heat-diffusing cast iron pan if necessary. Heat until thermometer reads about 400 degrees. PLEASE NOTE: A thermometer is going to give an incurrate reading when the inside of the popper is shiny and reflective, so use a LOWER heat until the popper is broken in and seasoned.
- Put your beans in the popper and start your medium paced, steady cranking. Thermometer will drop to around 350. Don't let it drop much below 300, or get much above 400 except at the end. These temps are starting points; you will ultimately personalize the process once you have done it a few times. And remember, you are measuring the air temperature in the popper, and the actual temperature on the bottom will be higher. DO NOT ROAST BY TEMPERATURE ALONE - watch the beans and popper to be sure the roast is moving neither too fast, nor too slow.
- Around 6 minutes you should hear the "first crack" and see roast smoke. Wait 1 minute and slightly reduce the heat (or lift the popper off the heat), not so much that the roast stalls, but enough so that the roast does not progress too quickly. Start checking the roast by flipping back the lid at about 30 second intervals or less. Second crack ought to occur anywhere from say 9 minutes to 12 minutes, depending on how you like to time the roast. TIP: If you can learn to roast by smell and sound only (and avoid opening the lid), you can reduce escaping roast smoke and any reduction in temperature.
- You want to pour the beans out of the popper into a colander when they are a tad lighter than the color you desire, since roasting continues a little into the cooldown process .
- Agitate beans in metal colander or bowl with a big spoon until they are warm to your touch. You may need oven mitts for this. You may want to shuffle the beans between 2 pans/ colanders.
- You may want to walk out to a porch to aid cooling.
- If beans have light colored chaff still attached to them, simply agitating them in the colander should remove it. If you blow lightly on the beans the chaff will fly off, but do this outside or over a sink to avoid sweeping the floor. Chaff has no flavor so if a bit of chaff remains with the roasted coffee, it is of no real consequence.
- Coffee should be stored out of direct light (and not in a fridge or freezer) in an airtight glass jar, but with a fresh roast, wait 12 hours to seal the jar tightly; it needs to vent off C02.
More Tips:
If the agitator jams while cranking, don't force it. Work it free by cranking the opposite direction. When the popper is cool, see if you can bend the agitating tines to hug the bottom of the pan a little closer.
If the flame is too high, or you worry about burning up the pan, you can use a cast iron pan, or cast iron heat diffuser under the pan.
Having trouble getting an even lighter roast? You need to slow down the initial warm-up period of roasting (from the time you put the coffee in until first crack).
Clean the popper with scalding hot water every so often to reduce the coffee oils ... it is not necessary to clean it after every roast. I clean mine after every 15-20 roasts.
Modifications and Refinements:
- We recommend Home Coffee Roasting by Ken David's for more information. You can use the stovetop popper without a thermometer - but the thermometer gives you more information that can help you make roasts more consistent. Stove popping is great! It's like cranking an old butter churn or a meat grinder.
- Resist the urge to peek all the time! Listen to the sounds and smell the steam/smoke. After you do this a few times, you'll know what stage the roast is without looking, which lets a lot of heat escape and makes the kitchen smokier. Remember, first crack sounds like corn popping, while second crack sounds like the snap from an electric spark (or a "snap" in the sense of "snap, crackle pop").
- When the roast is done, there may be a lot of smoke that makes it hard to judge the color. A good overhead light helps a lot. I keep the popper closed, walk outside with my metal colander, and then transfer the beans.
