Friday, July 15, 2011

Semi Low Tech Coffee Roasting- Roasting on the Cheap

It is once again time to wax poetic about coffee at the Homestead. Coffee is a big deal here and an ongoing obsession for my brain and palate. We really don't drink that much coffee, once a day, sometimes twice on those days we need to get a lot done.
But we like really good coffee and are more and more reluctant to drink substandard coffee.
Since we are conveniently located in the middle of nowhere and about one hour away from our nearest micro roasters, I am determined to master the full process of our coffee, short of growing and picking, which would be pretty tricky here in Oregon.

In the true tradition of Homesteaders, who roasted their own coffee before commercial entities came on the scene touting their vacuum packed "fresh" flavored coffee in a can somewhere in the early 1900's, I have a passion for coffee DIY.

As you may remember we do most of our coffee brewing in a stove top Moka Pot and I found a very old, hand powered coffee grinder at the thriftstore that does a very good job of getting a nice even and fine espresso grind.

For months I have been researching methods for home roasting and combing the thriftstores for a double paddled bread machine to build a roaster set up like my friends.
I had already ordered my green beans from 7 Bridges Organic Coffee in Santa Cruz. I chose a 10 variety 5 lb. sampler for the beginning roaster and I'm really glad I did. It is a nice assortment and it gives me a chance to mix different flavors and at least get a rough idea of what I like before I buy larger amounts. They have a great primer on home roasting coffee on their website.

While cruising the small appliances in an odd little thrift shop, I happened upon a George Foreman Jr. Rotisserie Oven.
"Hmmm" I said as I examined the vegetable basket that came with it. It was $14.99 and looked like it had been used once. My calculations for batch, bean size and temperature clicked off in my head.
This was a definite possibility. I snapped it up.

We plugged it in at home and watched the temperature hover at 325F. That is about 75- 100 degrees lower than I needed.
After a few weeks of cogitating (should I insulate the stove better or override the thermostat or...) I decided that what I needed was the additional heat from a Heat Gun, but not just any heat gun. I wanted one with variable temperature settings, not just "High" or "Low", this was a little trickier since I didn't want to spend much. Once in a while I would do a search of the internets and I could find them but they were "Professional" and cost upwards of a hundred dollars. Until one day I found for a measly 20 bucks ta da ta da da da da daaaa:

After I received it in the post, I realized that I really didn't know how I was going to get the heat of the gun into the closed oven. But where there is a will, there is a way. Or should I say where there is a drill...  
On the right hand side of the oven the rotisserie motor resides. On the left side of the oven there is just a fake plastic grill and beneath that is the metal wall of the oven. I cut out the plastic grill with tin snips and calculated the area in which the gun would not interfere with the pivot point of the basket, but still point the gun at the beans in the basket. I began drilling multiple holes in that general area. When the area had more holes than metal I proceeded to snip the metal left between the holes with my tin snips, making a ragged hole approximately the size of the snout of the gun.
I had to enlarge it a little with the tin snips by cutting little fins around the edge, which turned out to be a great thing. After I inserted the gun, I just used a little ball-peen hammer to tap the fins down tight to the gun snout. It holds it so well I did not want to take it apart to show you. You will just need to surmise what I did from the photos. If by chance the heat gun did not stay put, I was going to use a large hose clamp on the interior part of the nozzle to hold it in place.

If you use this oven method, do yourself a favor and get an Ove Glove. Blistered knuckles over ride all feelings of well being while sniffing your newly roasted coffee.

I trimmed away the plastic until the heat gun could fit all the way in. I did not want the hot metal nozzle to rest on the plastic outer body.

I pounded in the crumpled metal to hold the nozzle of the heat gun tight.

This photo shows where I settled on the heat setting- for now. This will most likely change as experiments progress.

These are the pans I used to cool the beans as soon as they came out of the oven.
Green beans

The stove is a little weird in that it has no "off" button. It uses an egg timer style knob. To roast coffee you just have to unplug it at the right moment when the basket clasp is at the front.


Unlike the Bread Machine set up, the oven lets the chaff sift to the bottom instead of flying around plugging up your heat gun intake.

First roast- a nice Viennese
Second roast- a City Roast
Roasts compared
I will not be able to give you real roasting stats for some time, but I will tell you for now that when roasting 1/3 of a pound of coffee (I am doing very small batches to get the hang of it) it takes about 6 minutes to reach first crack and somewhere around 7.5 minutes to get to City Roast +.

My first attempts have been met with very high reviews. I don't know if I hit a very good mix of Sumatra and Peruvian or if there is just no way to mess up fresh roasted coffee but I am very excited to continue the experiments. I bought myself a note book to write down the details.

Now the real fun begins!


  1. What a hoot, Phoebe! You're a riot - I like how you kludged that together. You're a candidate for a Red Green award! I'm not a coffee drinker normally, but you could convert me. That looks like a great roast! Well done - ingenuity at its finest!

  2. Thanks! Red Green, I haven't watched that in ages. I'm going to have to get those from the library again.
    Yes, sometimes I can be very careful but I am often MacGyver-ing it. Oh well... if it works Great, if not, I didn't invest a fortune and a bunch of time.
    Everyone I know who is not a coffee drinker changes their mind when they taste fresh roasted coffee, made well- just sayin':-)

  3. Looks like great results from a thrifty start in home roasting. I'm looking forward to seeing your progress on this project. :)

    From what I've read, it does seem like home roasting is the next big step in coffee quality, after home grinding. Robin and I have been on a big coffee kick lately, and I'd like to try ordering from a few online roasters to see how their quality compares to the beans I can buy locally. It will also be a good reference point for us when we starting trying to roast at home.

  4. Hello, this is Humberto Pow from Monterrey mexico, after the beginning of building a roaster , i bough the same rostiser before i got your web site, and ordered a chinese drum, made the holes for the george oven, thinking about insert a thermometer and a heat gun blower, then searching the web i found you site, so i was wondering who could build one like mine, and surprise, you builded first same components, glad to know about you, my email is : elpow@live.com


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