How does espresso differ from other coffees and brewing methods?
Originally, 'espresso' meant a cup of coffee made expressly for the customer - that is, brewed to order. This gives a much fresher cup of coffee than one previously brewed and kept warm. Over time, espresso has also come to be synonymous with the method of brewing (the equipment) and the coffee (espresso blend). Although espresso can be made with any beans, it is typically made with a carefully selected blend that gives great flavour, a balance of taste and aroma that can produce both good crema and particular flavours on the palate. Descriptions of espresso range from "chocolatey" to "fruity", "spicy" etc, so the blend is important in achieving the taste required. The degree of roasting plays an important part too, since flavours will vary dramatically from light to dark roasts. Beans tend to perform better, or produce their characteristic smell and taste, at a particular roast level. Over-roasting, particularly, tends to give a bitter coffee, while under-roasting gives a more 'grassy' taste.
Espresso making is a particular process, and this process is important, since it differs from other brewing methods in specific ways. An espresso takes around 22-30 seconds to produce, a much shorter time than other brewing methods such as drip or french press. Because the hot water is in contact with the coffee for less time and at a slightly lower temperature, this inhibits the amount of caffeine in the drink (espresso contains less caffeine than regular drip coffee, or even tea). If the espresso procedure is followed correctly the resulting drink is perfectly made - neither bitter nor sour and at the correct temperature for drinking.
Because espresso is brewed at high pressure special things happen during and after the extraction. This method of extracting fresh ground coffee produces the crema that is so specific to the drink.It is described as a polyphasic colloidal foam. Polyphasic means changing states/phases. With over 800 aromatic compounds continuously breaking down and combining and the crema releasing its gas and aromas continually, espresso is truly a different experience, one that can remain on the tongue for many hours.
How do I know if it's a good espresso?
There are many clues to a bad espresso: Little or no crema , pale or white crema, too much volume. A chance glimpse the machine being used can often give clues - a dirty machine can point to sloppy practices that will show in the cup. However, an espresso may look visually fine - nice crema and the right volume, but still taste wrong. This can be due to many factors: incorrect brewing temperature, dirty machine, insufficient coffee used, stale coffee, wrong sort of coffee. Although a well trained barista is the key to a good espresso, modern "superauto" machines have taken a lot of the guesswork out of espresso production, and, using automated procedures, are often able to deliver better espresso than that made by an inexperienced barista.
What about beans?
Espresso is usually made with a blend, although some single varietals of coffee can make a good espresso. A traditional Italian espresso may have 5 or more different coffees in the blend, although at least three are usually present. The quality of the bean is very important. Freshness of beans is important. Green (unroasted) coffee beans can last years, roasted beans lose their freshness in a much shorter time. In an ideal world the beans will have been roasted not more than a few weeks before use. However, in practice, various technologies are now used to lengthen the shelf life of roasted coffee significantly.
Cleaning your machine.
To achieve the best results possible, it is essential to keep espresso making equipment clean. Regular cleaning of the portafilter and group (including backflushing or rinsing the group) as well as removing the basket after use for cleaning is an essential part of the espresso routine if you want to brew excellent espresso every time. It is therefore worth spending the time neccessary every now and then to make sure that you get consistent quality of taste as well as keeping your machine in good condition.The cup is one of the main factors when trying to obtain and taste a perfect espresso coffee, but very often scarce attention is paid to them as they are commonly thought to have little importance. On the contrary, it`s quality is directly related with it`s temperature, a key factor when trying to extract all aromas being responsible for a proper cupping,First of all the cup must be round with internal walls resembling an inverted bell, Heat will make it easier to create a consistent crema of walnut colour. The best material os porcelain china ( with thick walls being the Italian manufacturers specialising on this type of cups) that help preserve as much as possible the brewing temperature from the coffee group (90-95c)A preheating of the cup at approximately 40c (either with a steam cup heater or with hot water) will assure you that the coffee will be hot from the first to the last sip.
