Roasting coffee in wood fired ovens.

Keep the beans moving so they don't burn.

For the past 7 years I have been roasting our household coffee in the wood oven , and while I don’t claim to be an expert, I have now roasted over 300 times and you can’t help but learn a few things along the way.

First thing , Why bother ? Well, by buying green beans you will find it a whole lot cheaper than at the gourmet coffee store . I can buy organic, shade tree, fair trade , ethical coffee, in bulk delivered to my door in the Canadian outback for $4 a lb. That very same stuff roasted can cost you from $12 -$16. You can get regular non organic Brazilian for much, much less.

Green coffee is not taxed when it comes in to most countries, and here in Canada it’s considered food , so it isn’t taxed when you buy it either.

Second , it’s just so fresh ,…….. unless you have a nearby coffee roaster you are buying stale coffee. Starbucks for instance, has to let their their coffee sit around for several days before shipping, because fresh roasted coffee de-gasses for up to 1-3 days [depending on the variety] , so it will blow up those foil bags if they don’t . Fresh roasted coffee is fantastic , you can make it really strong [we make espresso] and it is never bitter.

sweep the embers aside for the roaster

Thirdly,…… heck! who needs any more reasons …..…..

Now you need some beans . Do an internet search for green coffee beans in your locale . I have been using [a green bean source in Toronto that ships North America wide] for all the time I’ve been roasting .
Right at the moment I have Peruvian , Bolivian , and Nicaraguan on hand .. it’s green state coffee beans will last for years..……. roasted they start to change flavour in a week. Some varieties say they are better for espresso , but I dark roast them all and they taste fine.

green coffee ready to roast

I made a roaster out of two dollar store stainless steel sieves . I made a wire hinge on one side , bent up a little clasp for the the other side and welded up a skid plate and long handle [see photo] , now this works fine for me , but if you don’t have access to a welder you can use a baking tray with a rim ..
Spread your beans on the tray , slide it in to your hot oven [ 500f+ ]. leave in for 4–5 minutes, pull out, turn with spatula , put back in and repeat till you get almost to your preferred colour [they keep on cooking after you get them out]]. This will take 10-15 minutes depending on how much you are trying to roast at once and the heat of your oven.

With the dollar store roaster I wait till the soot is almost burned off the dome, clear a passage down the middle of the coals , and slide the roaster back and forth with a jigging motion that keeps the beans rotating .. this will take between 8 and 12 minutes depending on the quantity and how hot your oven is . My dollar store roaster can handle 1 1/4 lb.

letting the roasted coffee mellow

Roasting coffee beans goes through several stages , at first the outside layer [ the silverskin ] will flake off , you can see them turn black on the oven floor , then as the beans heat up there will be a light cracking noise as they expand slightly , a few minutes later as the beans start to colour you will have to pull them out and visually check the colour . Next you will start to see smoke and hear a more pronounced and rapid cracking , the beans are expanding again , I start looking for an oily surface on the beans…. as with the baking sheet method they will keep on cooking so take them out before they get to your desired finish. Since we do espresso I want to see a mahogany colour that will finish outside the oven to a shiny dark chocolate.

who want's some coffee?

Remove the roaster and empty the beans on to a baking sheet , at this point if they are a little light you can leave them in a heap while they smoke , then spread them out , or if they look good , spread them out , give them a light mist of water [ the commercial roasters use compressed cold air ] to stop them from going too far.
For way too many months of the year I can put the whole tray down in a snow drift and stop them in their tracks . ( How I fire my pizza oven in winter months . )

More than a few time people have said to me , “can’t you make a rotating basket so you just have to turn a handle ?”.. Perhaps you can, but it’s beyond my personal cave man engineering skills. And with the judgment calls on the doneness that require removal and inspection, I can see this getting a bit tricky.
So there you go , fantastic coffee made easy , at a price that’ll make you pinch yourself .. How cool is that?
Like with cooking , you will make mistakes , but as with cooking you can still eat your mistakes or in this case drink them .