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! [top]


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. [top]



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. [top]



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. [top]



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. [top]


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. [top]