As a child I always loved the smell of roasting coffee. There was a cafe in the High Street which every Saturday morning would roast coffee using a tumble roaster in their window, and the aroma would drift down the street. I would sometimes just stand outside and sniff! But I didn't drink coffee at all, though I loved coffee creams.

when I got older though I discovered that coffee was very nice to drink, and started to drink a lot of coffee, indeed I've used-so-much-they-broke four espresso machines but now I tend to have just one or two cups of joe every day. The first of these will usually be taken in bed while checking up on the world outside via my phone's browser.

Because I still get through a pound bag a week though I tend to buy it pre-roasted and often ready-ground. But not always. Some ten or so years ago I started home roasting, keeping on hand a range of different green (raw) beans to roast. The supplier I used to get my beans from, however, stopped trading a while back, which was a great shame, but recently a place down in Soho has expanded their range of green coffees so I'm back to doing my own occasional roasting.

And here's how …

Starting off

Raw beans – called 'green' – are the stuff which your caffeine dreams are made of. They will last years in this state with no preservation or special treatment required, unlike roasted beans or ground coffee which (if you look after it very well) might be ok up to ten days from being roasted. I usually roast around 2oz or 3oz at a time because of the way I produce it, however you can buy 'proper' coffee roasters which will take up to ½ lb or more (if you don't mind handing over a substantial wad of cash.) The beans in this picture were a Yemeni arabica.

The Roaster

I use a popcorn maker which, for me, does the perfect small-batch job of controllable roasting. You can't use just any popcorn maker though! If you look inside your popcorn maker you'll probably see a mesh grille on the bottom where the hot air is blown in. This sort must never be used for roasting coffee. The type required is where there is a metal cylinder with angled slits around the side of the cylinder plus a solid base. When coffee roasts a lot of oils come out of the beans and these would drain through a mesh grille, shorting out the electrics. With the solid-and-side-slits type the oils just create a dark, shiny patina on the metal. Needless to say, once you start using it for roasting coffee you won't want to make popcorn in it again.

Temperature control

Something that books and other websites make a great deal of is temperature control. Firstly, because to roast coffee you need to get the degrees up, and secondly because stability means an eveness of roast and better quality. For the first of these I found that making a perforated cover was the way to go. Yes, you recognised it correctly, it is part of the drip try from an old espresso machine, bent to shape so as to not fall off. It gets very hot in use so always use an oven glove (indeed the whole 'popcorn' roster does so gloves are the order of the day throughout.) The holes mean that the smoke can escape easily, rather than building a separate chimney.

The Roast

Roasting coffee happens in stages. As the beans whizz round and heat up they start to expand – in much the same way that popcorn does – and when this gets properly started you will hear what is termed 'First Crack. The beans have started the change from their raw green state into the roasted bean we know and love so well.


The by-product of this cooking is that thin flakes will be shed by the beans, similar to the chaff when wheat or barley is milled. This chaff will go *everywhere* and in my experience there is little point in trying to contain it within your apparatus, instead getting the vacuum cleaner out after you have finished is more effective. During the roasting process it helps to chivvy the beans a bit, for which I use a single wooden chopstick. It will be very hot above your set-up!

Second crack

As the coffee beans continue to expand, their oils will start to coat their surface and you will see the reflections off of each bean. Sadly photographs really can't do justice to their beauty. This 'second crack' period is when you need to decide how you want your roast. Some beans demand a 'light' roast to bring out their flavour (eg. Blue Mountain) whereas others want a 'French', 'Italian', 'dark' or 'city' roast for a full-bodied jolt of flavour. There is also the matter of personal taste: I'm really a lover of very strong, dark roasts, for example, so that is the way I usually prepare each batch.

Finishing off

Once the beans have reached the colour and style you want you need to stop them cooking further as fast as possible. First step in this is to get them out of the heat …

Rapid cooling

... then you can either blow them cool or – as I do – put them in the freezer for a few minutes in a metal tray which you've let get cold before using it.
The beans will only need to cool down for a few minutes, so it won't cause any problems with the rest of your freezer's contents, although there may be more smoke initially.

Nearly ready

Although the now-cooled coffee beans look ready for grinding, they aren't. There is nothing to actually stop you grinding and drinking some immediately (and very nice it will be too!) it should really 'de-gas'. After the beans finish cooking they will be lighter in weight than the original green beans and will continue to give off gas once cold. This is why even shop-bought bags of beans and ground coffee have one-way valves.
to be fair they weren't really expensive ones