Roasting Coffee

December 5, 2010 – Sharing what I’ve learned about roasting my own coffee.

By The Cerebral Aesthetic Vagabond

I’ve been roasting my own coffee for about five years and I love it! I honestly think there’s no comparison between fresh roasted beans and store-bought, already roasted beans. The difference between fresh roasted and previously roasted beans is akin to the difference between whole beans and already ground beans.

Not everyone is a coffee connoisseur, or as I like to call myself, a coffee snob. For some people, the mere belief that they are drinking a liquid called “coffee” is sufficient. Witness the countless commercial establishments that serve coffee that might very well be dirty dishwater, and yet the customers lap it up without complaint.

Me, I like my coffee like I like my women – strong, rich and black. (Just kidding about the women part.) I once made coffee for my sister and, trying to be diplomatic, she declared that it gave her heart palpitations. I have only one cup a day, in the morning, so it has to be strong enough to last me the entire day!

Why bother to roast one’s own coffee when one can just go down to the store and buy it already roasted, even ground as well? It’s not for everyone, that’s for certain. For me, roasting my own coffee appeals to my “do it yourself” mentality, my passion for cooking good food and my controlling tendencies. Among other things, I like to vary the degree of roast to achieve different flavors from a single bean. There are some practical reasons for roasting one’s own coffee, however, including longevity and cost reduction. Unroasted green beans keep for a long time, unlike roasted coffee, the flavor of which deteriorates rapidly. Green beans also cost quite a bit less than roasted coffee beans, about $5 per pound for the varieties I buy. Even exotic varieties of green beans seldom cost more than $10 per pound. There’s one more advantage from roasting one’s own coffee: a wider selection of beans from which to choose. My last order consisted of twenty-four pounds of green beans from four different continents.

Automatic Roasters

When I first started roasting coffee, I used an automatic roasting machine, which worked great, until it didn’t. The one shown below worked satisfactorily – albeit deafeningly – for a couple of years and then began to malfunction, three times shutting itself off abruptly in mid-stream and threatening to catch fire. I would say one needs to keep a close eye on these things.

Automatic coffee roaster

The inexpensive coffee roasters like the one shown above – inexpensive is relative, as this one cost about $180! – are not unlike popcorn roasters, relying mostly on hot air to roast the beans. The vigorously flowing air also assists in the removal of the chaff from the beans, a skin similar to that on a peanut, although thinner. The flowing air blows the chaff into a collector. With the heating element turned off, the flowing air is also used to quickly cool the beans once they have reached the desired degree of roast. While $180 may not sound inexpensive, the more durable, higher capacity roasters can cost as much as $1,000, which is a bit too steep even for a connoisseur like me. However, the higher cost might be appropriate for a commercial establishment.

“Manual” Roasting

Ever since I started roasting my own beans, I have wondered how practical it would be to roast them in an ordinary pot on the stove. When my automatic roaster malfunctioned for the third and final time – I think I’m going to send it to coffee roaster heaven before it burns the house down – my opportunity to roast coffee on the stove presented itself. So I added the word “pot” to my weekly shopping list (no, not that kind of pot) and picked up a small stainless steel pot for $10, far cheaper than a new automatic roaster. The main impediment until now to roasting coffee on the stove was that I knew the roasting process would discolor the pot and I didn’t care to sacrifice one of my nice pots. Now that I had a pot dedicated to roasting coffee, I proceeded without delay.

Beans beginning to roast – notice their slightly brownish color. The bowl of cold water is to cool the beans quickly when they reach the desired degree of roast.

A word to the wise: roasting coffee, whether using an automatic roaster or doing it on the stove, produces a lot of acrid smoke. When I first started roasting, I just did it in the kitchen and let the smoke fill the kitchen. The roasting machine I used could roast only a small quantity coffee, so the amount of smoke wasn’t intolerable and dissipated quickly. With the roaster shown above, which roasts a larger batch than my first roaster, I used some dryer duct to vent it out the window. Now I have a house that has an honest-to-goodness working exhaust vent above the stove, and that works the best of all and permits me to roast in an ordinary pot on the stove. Of course, climate permitting, one can simply roast outside, and I have done that as well, although here in Kentucky where the high temperature today is 35 degrees with a fierce, icy wind, roasting outdoors is not very appealing, especially since even with the automatic roasters one has to supervise them carefully.

In order to achieve a uniform roast, the beans need to be circulated, whether in an automatic roaster or in a pot. The automatic roasters rely on the blowing air to circulate the beans and produce a pretty even roast. Although there are mechanical stirrers designed for stovetop roasting, there is a simple invention known as a spoon that works just as well. In fact, until the latter stage of the roasting process, the beans can be circulated pretty well by simply shaking the pot gently from side to side. Beware, holding one’s hand over the pot while stirring the beans will likely leave it smelling of roasted coffee for a couple of days! If that is objectionable, one should consider wearing some kitchen gloves while stirring the beans.

Cooling the roasted beans in the bowl of water. The beans must be stirred continuously while sitting atop this water bath until they stop smoking.

I have roasted two batches of beans on the stove since acquiring the roasting pot. The first batch I roasted at a higher stove temperature and although the resultant coffee tasted great, some of the beans looked a tad bit burned. So I roasted the second batch at a lower temperature, about one-third of the maximum setting on my stove. Roasting at a lower temperature took longer (about 30 minutes), but produced a more aesthetically pleasing result, shown above.

Using my small pot I can produce about the same quantity of roasted beans as the automatic roaster, or about three days’ worth, which is ideal since I’ve found that fresh roasted coffee experiences a noticeable decline in flavor after about three days. However, this technique can be employed with any size pot, permitting one to roast a large batch of coffee if desired. Just remember that the larger the batch, the more voluminous the smoke.

Coffee beans, before and after

As anticipated, the roasting process quickly discolored the roasting pot, as can be seen in the photo below, which was taken after roasting just two batches, and after cleaning the pot!

Discolored roasting pot after just two roasts

Comparison of Roasting Techniques

The table below summarizes the differences between roasting with an automatic air roaster and roasting in a pot on the stove.

Automatic Air Roaster Roasting In A Pot On The Stove
More convenient, although the roaster has to be carefully monitored for safety and a proper roast, and it needs to be manually switched to cool mode when the proper roast is achieved; I’ve never been able to rely on the machine’s timer to produce a satisfactory roast. One must stand (or sit) in front of the stove for half an hour or so, periodically shaking or stirring the beans; cooling the beans is also a manual process, but a brief one.
Requires expensive equipment that can be very noisy and will eventually wear out; I’ve found that the “inexpensive” roasters last only a couple of years, and I’m gentle on them. The equipment is extremely inexpensive and can potentially last forever.
The less expensive roasters can roast only small batches; in addition, the roaster shown at the top of this post is emblazoned with a stern warning to allow it to cool thoroughly between batches, and that warning must be taken seriously. The batch size is limited only by the size of the pot used; multiple batches can be roasted back to back or even simultaneously on different burners.
Takes about fifteen minutes to roast a batch, but the roaster needs to be cleaned of chaff after roasting; in addition, the roaster parts need to be cleaned of coffee residue from time to time. Takes about thirty minutes (less time if a higher temperature is used) and only the pot needs to be cleaned.
Removes the chaff. Doesn’t remove the chaff, although the chaff is tasteless and not objectionable. One could put the roasted beans in a bowl, stand outside and toss the beans, allowing the wind to blow the chaff away.
Requires electricity and the roasting time varies with voltage. Can be done on any cook surface, including an electric range, a barbecue, a wood burning stove or a camp stove.

How to Trigger Heart Palpitations

Now, to the all important question of how to make coffee that triggers heart palpitations. The answer is simple: make one cup at a time and put a lot of coffee in the cone.

Coffee cone to make one cup, and poor man’s alternative

Coffee vendors used to sell these coffee cones all the time, but they seem hard to come by anymore. They can occasionally be found sold with round glass coffee pots in grocery stores. However, if one cannot find an “official” coffee cone, an ordinary funnel works just as well and costs a fraction of what the cone costs. Either of these fit comfortably over a coffee cup while brewing the coffee, although the funnel needs to be removed sooner than the cone to avoid having the cup overflow.

With either of these devices, one can use any sort of coffee filter or, I suppose, even a folded paper towel in a pinch. I use basket-type filters intended for automatic coffee makers, but they work just fine in these cones and are a heck of a lot cheaper than the filters intended for use with cones.


Having at long last confirmed that one can roast coffee on the stove, provided one has an adequate ventilation system, I think I will do it this way from now on. Roasting on the stove takes about twice as long as with the automatic roaster, but is easier to control the degree of roast, less noisy, less dangerous and more flexible. I can roast small or large batches on the stove; I can roast indoors on the stove or outdoors on a barbecue, an electric hotplate or a propane camp stove; and the equipment cost is next to nothing and more durable.


I have only one resource to recommend to people who are interested in roasting their own coffee, but it’s a good one: Sweet Maria’s. I’ve been buying coffee and equipment from them for five years and they are excellent. They sell green coffee, roasters and other equipment and their web site is chock full of information about coffee roasting.

The End