FOUR
ESSENTIALS FOR GOOD COFFEE
Anyone
wanting to make a good espresso has to meet four essential needs.
The first is the choice of the right blend, the second is a proper
espresso machine - properly maintained, the third is the right grade
of grind and the fourth is the knack with which the measure of coffee
is pressed. Espresso must be easy on the eye (with froth - also
known as cream - which is thick and nutty-red in colour), the nose
(with a rich aroma) and the palate (almost chocolatey). And of course
it has to leave a pleasant taste in the mouth for a good long time
after being drunk (after-taste).
The machine should be carefully looked after to make sure that the water
temperature is correct, the water has the right degree of hardness and
the parts are clean. The nozzle for frothing the milk should be cleaned
every time it is used and the filters, filter holders and dispenser groups
washed at the end of every day - and no detergent please!
The degree of the grind should be carefully adjusted on the grinder. Coffee
is highly sensitive to humidity - in dry weather the grind needs to be
a fine one, while damp or rainy conditions require a coarser grind. An
espresso measure is between 6.5 and 7 grammes. The grinder should be cleaned
regularly, especially the bell containing the beans.
In addition to bearing the above points in mind, you should press the
measure of coffee so as to distribute it evenly. A good espresso will
pour down in an unbroken walnut-coloured stream for about 20-25 seconds
per cup. The result is a total of 30-35 ml of coffee in a pre-heated ceramic
cup.
ADVICE FOR AN OPTIMUM ESPRESSO
An espresso can be judged by a simple look. An optimum espresso looks
good - thick and lasting cream with the sugar sinking slowly through,
an inviting dark nutty colour with reddish highlights and slight streaks.
This optimum result is not easy to achieve. Many variables can lead to
a negative outcome - an inadequate blend, improper maintenance and use
of the equipment (espresso machine and/or grinder-dispenser), wrong grinding
setting, coffee left to oxidise in the air for too long.
The two most common defects in an espresso are underextraction and
overextraction. As may be understood from the term, in the former
case the components needed for a balanced coffee are not sufficiently
extracted, and in the latter in which too much is extracted, but
the result is no better for that.
The results in the cup can be predicted as soon as the coffee begins
to emerge from the spout of the espresso machine. Underextracted
coffee pours out very quickly, in less than the prescribed 20-25
seconds, in a continuous non-creamy jet. The coffee will have a
light-coloured, almost whitish, cream of low density. Overextracted
espresso will pour out slowly, drop by drop, taking more than the
standard time. Its cream will be dark, of low density and short
duration.
These two defects can have a number of causes. Here is an analysis of
some of them, along with the best ways to remedy them.
UNDEREXTRACTED ESPRESSO
The measure of coffee is insufficient. From a kilo of coffee 143-153 espressos
should be extracted, at a weight of 6.5-7 grammes per measure. A measure
weighing less than 6 grammes is likely to result in an underextracted
espresso. Check the weight of the measure and increase it to the standard
if necessary.
The grind is too coarse. The water passes through the coffee powder
too quickly, simply washing it without extracting the aromas and
flavours. Coffee absorbs humidity from the environment, so the grind
should be adjusted daily according to atmospheric conditions - a
finer grind in dry weather, a coarser grind in damp weather.
The measure is not pressed hard enough. A measure of coffee should
always be pressed when placed in the machine. This gives an even
distribution of the powder and makes sure that the water passes
through all of it. The measure can be pressed with a special tool
or using the shaped part of the grinder-measurer.
The temperature of the water in the espresso machine is less than
90°C. In this case the water has less strength to separate the
aromas and flavours from the coffee powder and carry them to the
cup. The boiler pressure should be increased to take the water to
the required temperature.
The pressure in the pump of the espresso machine is more than 9
atmospheres. The water is forced through the coffee too quickly
and the extraction time is too short. The pump pressure should be
reduced.
The machine is not properly cleaned. If the spouts are blocked the
water is not distributed evenly and part of the measure of coffee
goes to waste. The spouts should be cleaned with the blind filter,
as indicated in the instructions.
The holes in the filter have increased in size. This also means that the
water passes through the coffee too quickly, which leads to underextraction.
Filters should be checked regularly and replaced when necessary.
OVEREXTRACTED ESPRESSO
The factors leading to overextraction are similar to those causing underextraction,
and the same goes for the remedies.
The measure of coffee is greater than is necessary. It should be
weighed and reduced, if necessary, to the standard of 6.5-7 grammes.
The grind may be too fine. When wet the powder tends to form a kind
of mud that slows down the passage of water through the coffee.
In this case a coarser grind should be used.
The coffee has been pressed too hard. The coffee powder is too compact
to allow the water to pass through normally. Take care to press
more lightly.
The temperature of the water in the machine is too high (above 95°C).
Reduce the pressure in the boiler.
The pump pressure is less than 9 atmospheres. Adjust it to the proper
level.
The spouts are blocked. As in the case of underextracted coffee,
they should be cleaned with a blind filter.
The filters and filter carriers are blocked. Here too, the sensitive parts
of the machine should be carefully cleaned.
A bad coffee may be the result of several causes acting together. A daily
check on the cleanliness of the various components and proper coffee management
(appropriate degree of grinding and a quantity of ground coffee no greater
than immediate needs) are of basic importance for the preparation of a
good espresso. A good espresso cannot be obtained from a bad blend, but
if proper care and attention are not used during preparation an excellent
blend can produce a disappointing cup of coffee.
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