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COFFEE AND MORE
Knowledge
Family: Rubiacea.
Kind: Coffea.
Here is the botanical identity card of
coffee.
There are over 80 species of coffee in
nature, but the important ones from a
commercial point of view are only two:
Coffea Arabica and Coffea Canephora,
respectively known as Arabica and Robusta.
“Like coffee lovers certainly Know, to make
a coffee blend one must choose between two
coffee species from which originate all the
various sorts of this aromatic drink. These
two categories are Arabica and Robusta
Coffee.
Everybody believes that when you see 100%
Arabica marked on a coffee pack, that coffee
is better than the others. But it is not
always true. There are very good and very
qualities of Arabica coffee. The same can be
said for Robusta coffee. Therefore a 100%
Arabica coffee could also be poor quality!
The difference between these two coffee
categories is that Arabica coffee sorts are
more aromatic, more prestigious and delicate
while Robusta coffee sorts have a stronger
taste and give coffee more body and creamy
foam in the cup.
A well-balanced coffee blend is given by
mixing both coffee categories in the right
way.
Preserving
One of the most treacherous enemies of
coffee is time. Even the best products, in
fact, lose their fragrance and become easily
stale.
This is due to the coffee oil becoming
rancid, and particularly to loss and
alteration of the composition of a volatile
constituent of the coffee aroma. The main
cause of alteration is direct oxidation, by
the action of the air oxygen or indirect
oxidation by the action of the peroxides in
turn forming because of the coffee oil
oxidation.
The best way to keep the fragrance and the
aroma of the coffee unchanged is preserving
coffee in a hermetic container.
The coffee can even be kept in the fridge,
but only after having placed it in a
hermetic container. This avoids that the
coffee absorbs the dampness of the fridge.
The coffee can never be kept near foodstuffs
with strong smells (i.e. cheese, tisanes, …)
because, as coffee has a bent for absorbing
smells, it will change its taste.
Italian
style espresso
A separate charter deserves espresso coffee,
that method to make coffee that apparently
somebody from Naples invented because he
thought the time for making coffee was too
long: he had a personal one made by an
engineer from Milan.
An espresso is a type of coffee prepared by
means of a specific extraction method that
allows to obtain a very concentrated drink
with an intense taste and a rich aroma.
The extraction by the espresso method is
carried out with de-ionized water at 85-90°C
at high pressure 8-9bar; the time water and
coffee stay in touch is 15 to 35 seconds. 7
to 8g coffee per cup are used, finely ground
and roasted medium to dark. The drink volume
per cup ranges between 20 to 35 ml.
The characteristics of an espresso coffee
are the following:
The foam
It is obtained by the gas dispersion (air
and carbon dioxide) in the liquid; the
liquid part responsible for its formation
contains a type of oil that can be
emulsified in water;
The body
The coffee body is determined mainly by
the presence of oily emulsions formed
because of the presence of polar fats, that
is complex molecules able to stabilize them.
Furthermore, the concentration of the
extracted substances is higher then in
normal coffee, and a small quantity of very
fine coffee powder particles is also
suspended in the liquid;
The aroma
The intensity of the espresso aroma is
due in particular to the presence of foam
acting as a trap of volatile substances,
preventing them to escape immediately after
preparing the drink. The optimal espresso
coffee cup should therefore have
considerable body, persistent back taste,
intense aroma, rich taste and compact foam;
contrarily to filtered coffee, that is used
as drink, espresso is particularly used as a
kind of corroborating elixir.
How to make a good espresso coffee
1) Water temperature
Water temperature for a coffee machine
should be approximately 90°C. Over this
temperature coffee is darker than usual and
has a burnet taste, while at a lower
temperature it is very fluid and clear, or
it is said to be “under-extracted”.
2) Pump pressure
In a professional machine, the water
pressure should be around 8-9bar.
3) Coffee grinding
For an excellent grinding, the coffee powder
should be almost impalpable.
However the actual check can be made by
observing how the coffee comes out of the
filter holder (therefore during the output),
that shall be of the “mouse tail pipe”.
During hot and dry months grinding should be
“finer” and a bit coarser during the cold
months.
4) Dosage
As a matter of fact the optimal dosage of
ground coffee to pour into the filter holder
for a good espresso cup is 7 or 8 grams.
Below the specified quantity a very light
diluted coffee is obtained. Over this
quantity, on the contrary, the coffee would
be poured out of the filter holder slowly
and by drops and its taste would not be
particularly pleasant but still particularly
strong.
Making a good coffee has nothing to do with
quantity, but with the quality of the blend
used.
5) Warm cup
A tip that is actually not negligible is the
control of the cup temperature used for the
espresso. When the cup is cold, in fact, the
impact between hot coffee and warm porcelain
makes coffee cooler and makes it lose a
little foam and makes it also look lighter
than usual. |
