If there is any area of the "coffee culture"
filled with as many myths, superstitions, half truths and holy grail
searches as espresso perfection, it's got to be coffee roasting.
Coffee roaster manufacturers go to a very great deal of trouble to
produce modern, computer operated machines which can reproduce every
aspect of a particular roast profile. A "profile" is actually a way
of describing how much heat is applied to the beans, and for how
long, at each stage of roasting. By changing and tweaking the roast
profile, a master roaster can maximise the desirable flavours of the
Except...if you buy the beans in a supermarket 6
months later, only the "base" flavour will remain, and not much of
that. And even when they are fresh, 90% of the buying public won't
be able to taste the difference. It's important to recognise that,
while you CAN spoil a good coffee bean by roasting it badly, you
can't improve a bad one by roasting it well. Roasting techniques are
important, but ONLY if you are buying fresh coffee. If your daily
cup is made from preground brick packed beans purchased in the
supermarket, then all that matters is whether they've been roasted
light, medium or dark.
In general, a light roast emphasises the acidity
of the coffee, a medium roast develops sweetness, and a dark roast
brings up the body. This presumes that these qualities are present
in the bean to begin with, because many coffees lack some or all of
these characteristics. The roast profile CAN influence this a bit; a
fast roast will make the flavour "brighter" at the expense of some
body, a slow roast will bring up the body at the cost of some front
Some people believe that there is an ideal roast
for each bean, but in my experience this is only true for certain
bean varieties. Kenya AA is a fabulous coffee at every level of
roast from light to dark, but Yemeni Mocha only gives the true body,
acidity and chocolate aftertaste when exactly correct. For many
years Starbucks, building on the work of Alfred Peet, promoted an
extremely dark "Full City" (?!) roast as being ideal, earning for
their troubles the appellation of "Charbucks". Somewhere along the
way they lost Peet's concentration on FLAVOUR and instead went for
COLOUR. These days Starbucks have started to offer a variety of
roast levels ("Lighter Notes"), but of course they are trying to
promote the idea as if it's a new invention. This is generally known
as marketing "spin."
The original coffee roasting apparatus is an
iron pan with a well fitted lid, shaken vigourously over an open
fire for 20 minutes or so. This is incredibly labour intensive and
exhausting, especially considering that the amount of coffee
involved is rarely more than 100g at a time. This is also probably
the reason that home coffee roasting is "women's work" in Africa and
the Middle East. If you ever try this method you soon learn why
peaberries were prized; they roll around so easily that a great deal
less shaking is needed to prevent burning the beans.
Bulk commercial coffee roasting simply enlarged
on this, with a bigger "wok" shaped pan, more fire and more guys
around it with shovels, furiously turning the beans. Around 1800 or
so some bright spark came up with the idea of putting the coffee in
a horizontal drum and rotating the drum over the fire; this is the
basis of most modern roasters. The advent of electricity and
electric fans has also resulted in "Fluid Bed" roasters, where the
beans are suspended in heated air, but this is a relatively recent
development. The "guys with shovels" concept is still widely used in
Arabia and South East Asia, though these days the fire is usually
Up until the mid 1800's most coffee was roasted
at home, but after this large commercial ventures took over. An
American viewpoint of these developments is available in Mark
Pendergrast's book, Uncommon Grounds. Coffee went from a luxury to a
commodity within 50 years, and home roasting virtually disappeared.
However, the advent of the internet and the odd communities it
creates has seen a resurgence in home roasting in the last half of
the 1990's. The major nexus of this revolution is at http://www.sweetmarias.com, with Tom as its prophet; another one of the early
converts was Ken David at http://www2.lucidcafe.com/lucidcafe/aboutcoffee.html, whose book has nurtured a new generation of home coffee
My personal favourite method for home roasting
is using a popcorn popper, but these days there are a variety of
specialist machines available (not QUITE as sophisticated as home
breadmakers yet) which will do the job.
If you are eager to begin roasting your own
coffee, I'd suggest that the first step would be an in-depth
investigation of the two websites above. Home roasting isn't that
hard, but you do need to pay attention, and you need to know a bit
about the various stages that a coffee bean goes through during the
roast. See http://www.lucidcafe.com/homeroast.html for details, but the following is a rough
1) If air temperature is below 15C, preheat the
popper for 60 sec.
2) Add 80g of green coffee to popper.
3) Turn on popper and stir the beans in the
general direction of airflow. You'll get covered in chaff, but never
4) After 3 to 4 minutes the beans will start to
pop like popcorn. This is known as "first crack."
5) The pops will continue for a couple of
minutes, then stop. If you stop roasting at this point, you'll have
a medium roast.
6) After another minute or so, a quieter
popping/crackling will start. This is "second crack."
7)Stopping the roast at second crack will give
you a basic dark roast. As you go longer into second crack, oil will
appear on the beans and clouds of blue smoke will billow out, bean
colour getting darker until the beans are black.
8) Whenever you stop the roast, tip the beans
into a metal sieve, then toss back and forth into another sieve
until they are cool enough to touch.