Roasting Coffee at Home

I recently started roasting my own coffee at home.  This is far, far easier than I ever imagined.  I'm having a ton of fun with it, getting really great results, and potentially saving a few bucks (assuming I stop purchasing new gear).

It all started with a Boston Globe food section article, Bean Town, about people roasting coffee at home.  Then my father-in-law gave me a hand-me-down Technivorm KBT 741, the best home coffee brewer available.  Having a great brewer available to me lead me to want to ensure I had the best beans possible.  This in turn lead to investigating home roasting.

So, here it is.  My home coffee roasting setup.  Certainly part of the fun is figuring some of this stuff out for yourself, but I figured someone might find these details helpful.

Click the picture for a big version where you can see the little arrows and numbers.

1) Kitchen splatter guard from Target.  Use it upside down and there's a little lip around the edge to help hold beans in some.  Crease and fold a little on one side relative to the handle and it makes it a little easier to pour beans out.  This is held over the fan for cooling.

2) Honeywell fan also from Target which tilts 90deg. to point straight up.  It would be better to be pulling air down through the beans rather than pushing up, but this is working very well for me right now.  I'm cooling to room temp in less than 1 min. with 4.5 oz. of beans.

3) Weigh your beans!  It's the only way to get repeatable results.

4) I paid $19 for this 0.1 gram accuracy scale at a local kitchen shop.  You can get the same for less online.

5) A leather work glove allows me to pull the top off the popper even when it's very hot like when it's time to dump the beans at the end of a roast.  I found potholders & oven mitts to be too cumbersome.

6) Bowl for collecting chaff.  As long as the top and butter cup are in place the majority of chaff goes right to the bowl.  As soon as you life the butter cup chaff starts blowing straight out the top.

7) 1/4 lb. bag with a one-way valve for storing my roasted beans.  A little masking tape allows me to right the date and degree of roast on it each time I load it up.

8) Board tilts the popper at an angle which increases bean agitation inside the popper chamber.

9) The popper appears to be a Toastmaster/Poppery II store branded by Le Gourmet Chef.  It is 1200 watts and without modification it roasted too hot and fast.

10) A little piece of tin foil folded over this forward edge of the butter cup cut-out seems to be slowing the rate of melt here.  The hood and butter cup are deforming as a result of the heat produced by roasting.  They need to be replaced by a glass chimney once I find an appropriate one.

11) A Sunbeam candy/frying thermometer gives me a fairly reliable internal bean temperature.  I had two models to choose from and the one with a shorter probe fit perfectly.  I drilled a hole in the butter cup and used the included clip to hold the thermometer in place.

12) Radio Shack model 273-1512 transformer which I knew to use thanks to this article on Engadget.  This feeds power to the fan inside the popper at a mostly appropriate voltage.  Initially the fan seemed to run quite a bit faster.  I think it gets a little more voltage off the transformer than it did off the secondary heater coil.

13) The dimmer switch was necessary due to the higher fan speed I was getting once I broke out the fan from the heater circuit.  Now I get excellent roast control by adjusting the fan speed.  I start out at full power when the greens are heaviest and heat is begining to ramp.  As heat ramping slows, but the greens are getting lighter, I am able to lower the fan speed to increase heat retention in the bean mass and continue the temperature ramping.

14) The original rocker switch which came on the popper is still wired to the heater.  During roasting if I get too fast a temperature ramp or a sudden jump in temperature I can shut off the heater for a few seconds to get things back under control.