The green coffee beans have to be roasted to develop aroma, flavour
and body. The roasting process causes chemical changings in the
coffee. Soluble oils are developed, caramel is formed, the taste
and aroma develops and the colour changes from light to deep brown
shades. The roasting procedure can take up to 17 minutes for the
dark espresso roasts.
exactly happens during the roasting: After about 5 minutes in the
roaster, the green beans start to swell and change their colour
to yellow and then gold. After 9 minutes, the beans are even darker
and start looking wrinkly. Around 10 minutes the beans crack. Gases
inside them built up, swell them about double their original size
and crack open. This can be recognized and heard as a sound quite
similar to the one of popcorn. Now after 11 minutes, the colour
changes to a darker brown and can now be already taken out of the
roaster, if a lighter roast is required. After 12 minutes the colour
and aroma begin to intensify and a second pop can be noticed. At
15-17 minutes of roasting, the beans look very dark and are named
French, Italian or Espresso roast. As these roasts are the darkest,
the beans have to be taken out of the roaster now, to avoid burning.
it is also possible to roast all the beans for the same time period,
but the temperature changes according to the requirements for a
certain roasting degree . Due to the roasting, the bean looses about
12 – 20% of it’s weight, but it’s size increases
about 50 – 100%. The beans will be at their optimal flavour
after one or two days, during them they release vapor.
and medium roasts, which are milder in taste and preserve the acidity
and allow their beans to keep their delicate flavours and aromas,
are especially recommended for breakfast coffees and with milk.
A darker roast is more recommendable for after dinner and is best
drunk black. An Italian or French roast has almost lost all its
acidity and its distinctive flavours, but the strong, bitter taste
can be a real treat.