Stovetop Coffee Roasting


Stovetop Popcorn Popper Method (Whirley-Pop, SS Stovetop Popper)

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Features: Can produce any roast style, from City roasts to Dark French/Spanish roasts. Lighter roasts are more difficult with this method. Air roasting produces even roasts with less effort, but if you like doing things the "olde tyme way", you may enjoy this! Beans can be observed during the roast since half the Whirley-Pop lid is hinged and flips up. Since there is no fan or motor, it is very easy to hear the cracks with this method. This is a conduction method, and produces a roast close to drum roasting (just more smoky since there is no air flow). Can roast 8 oz of coffee at a time. More effort required than a roasting appliance or even an air popper because you have to crank to agitate the beans. And if you don't like this roast method, the stovetop poppers are incredible popcorn poppers!

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. 


The benefits of Stovetop roasting:

  • You can roast more in one batch than air roasters, and more than some expensive drum roasters! 1/2 to 1 pound batches are possible. With the Stainless popper you might be able to roast a bit more too. This means you can probably roast enough for a week in one sitting, and with 1 or 2 batches.

  • You can get good roast results through the entire range, from City roasts to Dark French/Spanish roasts. Lighter roasts are a bit more difficult with this method. But all levels can be done well with a proper technique.

  • If you like doing things the "olde tyme way", you may enjoy this! There's no electronics to break. Completely Y1k compatible.

  • It's fairly quiet and with experience you should be able to hear the first crack and second crack easily.

  • You can have total control over the length of the roast, getting more of a "drum roast" profile, which some people prefer for espresso.

  • You can go nuts and modify/customize the process endlessly. People have added spit motors or electric screwdrivers to power the agitator, bolted the roaster to camp stoves so it doesn't move around on them, installed thermometers of all sorts...

The problems with Stovetop roasting:

  • Stovetop roasting produces a lot of smoke, mainly because you are roasting more coffee in each batch. You must have a hood over your stove that actually goes to the outside, or roast outdoors on a camp stove ... or maybe you really like smoke..

  • This method requires some skill - you need to set the heat source so you don't roast too fast and scorch coffee, or too slow and bake it.

  • You need to be patient ... to roast coffee well the process takes 8 to 15 minutes, and you need to stand there and slowly crank the roaster the whole time. Sometimes the popper doesn't crank easily and you need to overcome that ...

  • ... Stovetop poppers might require some adjustments and occasional repairs to keep working right. You are on your own, since you are using it for an unintended purpose you can't expect a warranty to cover you. Poppers are for DIY people (do-it-yourself). You may need to fix gears, replace rivets with screws, modify the stirring paddle, etc.

  • Some coffees don't get along with stovetop roasters and tend to jam them up ... namely the Yemeni coffees and other small-bean types. Peaberry coffees roast especially well because they "roll" in the popper.
   

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:

Warm, fresh roasted beans are wonderful, but the coffee attains its peak 4 to 24 hours after roasting. If you store it as recommended, we'll call it fresh for 6 days. When you open that jar in the morning, you will know what fresh coffee truly is.

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:

Here's a helpful overview of the stovetop process written by Philip Scott-Smith. a home roaster on the island of Guam. It sounds like his inital temperatures are probably too high for the stainless poppers with the plexi window - unless you have modified the popper and replaced this with a pie plate:

"I believe I finally have the Whirley-Pop method worked out right.
The most important thing to remember is that the W-P is a CONDUCTION roaster. Consequently, the beans always are at risk from scorching. Even if the thermometer is reading acceptable temps, it's easy to get scorched results because simply cranking the agitator doesn't get them far enough away from the hot skin of the roaster.

Here's my new method, which has produced consistently superb coffee (possibly even better than my Hearthware roaster):

Here's is yet more feedback from a customer on his stovetop popper method - from Bill Baddeley 5/27/05:

I've been working with the steel version of the stovetop popcorn popper for the past several weeks, and I've gotten to the point of getting consistently good coffee from my roasting efforts. I found a few small glitches as I went along, mostly in the first roast.

•The popper has metal gears on threaded rods. When the agitator began to stick, prior to the first crack, I cranked backwards. The gears began to unthread from the rods, so I went back to "forward only" cranking. I put blue locktite (thread sealer) on the threads and replaced the gears, and have had no trouble since. The blue formula allows you to take the gear off if you need to at some later date.

•Shortly after I'd narrowly avoided losing the gears by cranking backwards, the clip that retains the handle on the crank rod popped off and rolled away. So, now we're cranking forward, and being careful not to slip the handle off the crank rod. And we're mildly apprehensive. I used a 5/16" O.D. c-clip to retain the handle, and it's been fine.

•The polycarbonate window sagged when the heat got too high, but stayed put well enough to get me through the first batch. I replaced it with a pieoe of sheet aluminum and that, too, has been fine.

•The thermometer fit through a #8 (8-32) t-nut with the threads drilled out of it. The gasket compound works very well, but I didn't use enough the first time, and the thermometer AND the t-nut wobbled around, giving me one more thing to try to keep lined up in that first attempt to roast coffee. I used a nut to secure the t-nut to the lid, and then the gasket compound, and it's been fine since then.

Your advice on listening and smelling the roast as it goes is excellent. It's much easier than trying to see the beans through the smoke. I had one batch that turned out to be a bit lighter than I wanted, so I poured the beans back into the pot, and roasted them a bit more. I had a couple of roasts that ran too hot and too fast: one so bad I couldn't drink it. But once you get the hang of it, the roasting process is pretty straightforward. And the coffee is wonderful.


Ye Olde Skillet Roasting (a Wok is acceptable too!)

Features: Fun and easy. Cheap and definitely "old school." This is the method I used to roast Tanzanian Peaberry (they roll nicely in the pan) 10 years ago. I thought I was the only person in the world roasting at home. This is better as an experiment, or for you cowboys and mountain men out there; the other methods produce better cup quality. It's easy to scorch the beans and produce uneven roasts. The pan needs to be covered and the beans need to be stirred without removing the pan from the flame (i.e. shaking the pan) ...not easy to do! But it doesn't cost much to give it a try! Even experienced roasters should try it once. You learn a lot by having the whole roast process unfold in front of your eyes...

What You Need: Any lightweight skillet with a good tight lid, or a heavy skillet for a real aerobic workout. (You might also try a Wok and agitate with a wooden spoon. With good technique, this method can produce fine results.) Gas or Electric stove. An oven thermometer . A big spoon, a big bowl or metal collander for cooling, and oven mitts.


Instructions:

Refinements: Use another method. Skillet roasting is fun and barbarous, but I must admit, after a while you can become quite intuitive and produce some good roasts. But in the meantime you'll ruin many good beans. An air popper is 93% foolproof! I have had more success using a wok than a skillet. Still, I am not a talented person with the wok technique. I do know someone who has great success because he uses a wood-type stove and the wok sits in a opening that exposes about 2/3 of its bottom surface area to heat. That means the coffee has more even contact with heat more consistenly than on a stovetop range, and the results are very good, so I hear. And he roasts 1 Lb. at a time...