# Ever tried making your own roaster? Here's mine.....



## oldroaster (Jun 19, 2012)

Hello Folks,

I've been home roasting for 35ish years and when I started there was nothing available for the keen coffee lover. The way things have moved on is just mind boggling, with lots of high tech models on the market. Well, all those years ago I decided to make my own roaster. I'm still using it every week or so and roast up to 500grms of beans each batch. I've used it hundreds of times and it has never let me down. It's based on a very much scaled down professional internal-gas roaster, but is heated externally, just over a gas ring. I got some perforated stainless steel sheet, the stuff they use in fish'n'chip shops for draining the oil. The holes have to be small enough not to let the beans drop through, but not too small or the chaff will get trapped. Mine are 4mm diameter. Roll the s/s into a cylinder approx 125mm x 160mm (you'll need access to a sheet metal roller s/s is tough stuff). I chatted up a local sheet metal worker, who was willing to help, especially when I offered him some freshly roasted coffee in exchange. Next, fabricate the ends of the cylinder, I used aluminium sheet as I had some lying around. A swinging hinged door is used for getting the beans in and out. To get the beans to tumble nicely I put an L shaped strip 1.5mm thick of copper 30mm x 155mm inside the drum, if you look inside your washing machine you'll get the drift. Through the centre of the 130mm ends is a steel rod bent into a crank to turn the drum. The cylinder is suspended on a simple plywood frame (make sure it's flame retardent!) which is placed over the gas ring. After the first few roasts I became aware of the need of a guard to catch chaff. This was made from thin tin plate. I roast by instinct and experience i.e. the smell, look, crack and smoke of the beans. I use no profiles, much prefering the unexpected, the last thing I want is consistancy in my coffee. Of course, it has to taste good! Hand turning means I can reverse the tumble at will, this helps to get an even roast. As I use a gas ring I can adjust the heat up or down to allow for the development of flavours especially during the exothermic stage. The holes are large enough for me to see how the colour develops too. The chaff drops onto aluminium foil placed around the gas ring, flaring occasionally, which adds to the drama. Smoke control is via our kitchen extractor fan, which vents outside and drives the neighbours mad with the fabulous aroma of roasting coffee. This batch, Peruvian, bought from Pennine Tea and Coffee(see pic below) was roasted for 23 mins to end of first crack, then rested still tumbling, for two mins with gas off to allow development of the flavours. Coffee is then tipped onto a marble slab to cool. So it's not too difficult to DIY. Why not have a go!


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## oldroaster (Jun 19, 2012)

Yes, still turning by hand. I did think of fitting a motor, but never got round to it. Probably never will now.


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## lookseehear (Jul 16, 2010)

I'd love to build something like this. Surely not ideal for the kitchen with the smoke generated from roasting?


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## oldroaster (Jun 19, 2012)

Well, if your extractor vents outside it's not a problem, certainly not for me anyway. Ours does not have a carbon filter which slows the flow of gases. With a re-circulatory type it certainly would be. If you have a smoke alarm in the kitchen it would trigger too. Of course the weight of beans you roast determines the amount of smoke produced so 250 grams, the minimum for a decent roast with my gadget, would be less smoky. It's also quite feasible to roast outside over a calor gas burner, though given this year's weather, perhaps not such a good idea!


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