In Italy, the birthplace of the espresso, there is a traditional rule known as the ‘Five M’s’. These must all be achieved to make the perfect, tasty espresso.
Espresso is rarely ever made with a single-origin coffee. As espresso intensifies the flavour, it is found that single-origin coffees lack balance because the espresso highlights one particular characteristic. To give an espresso complexity and balance, a blend of coffees from different regions is required.
The number of coffees in an espresso blend varies from roaster to roaster. Many small scale roasters will concentrate on between 3 or 4, so as to allow each coffee to add their indiividual character to the blend. But large scale roasters may use as many as 12 different coffees, so each is less distinctive, to minimise the variation in taste from season to season.
The exact espresso blend you choose is purely down to personal taste, but you should use coffee which is:
The freshness of coffee is vital for making great espresso. Ideally, your espresso blend should be between 2-10 days old (after roasting). Coffee younger than this can contain too much CO2 (leftover from the roasting process) and produce a shot with excessive amounts of crema that quickly dissipates. Coffee older than this may taste flat and have little or no crema.
The espresso blend you choose should use high quality coffee beans. However, this does not mean that the blend needs to be 100% arabica. Used sparingly, robusta beans can add a further dimension to an espresso blend, giving it that extra zing. The use of robusta in espresso blends is a hotly debated topic, with many arguing that it takes away more than it adds. But, it is a traditional ingredient of espresso blends from Northern Italy, and so you should not be put off trying blends that do contain it.
The optimum time (flow rate) to brew an espresso is between 25 and 30 seconds. This is the period when the majority of the flavour has been extracted from the coffee grounds but before the bitter compounds and excessive caffeine are released. In the process of making espresso, it is the coffee grinder’s role to control the flow rate.
If the flow rate is too fast, then greater resistance is needed to stop the hot pressurised water passing through the portafilter as quickly. This is done by adjusting the coffee grinder to a finer setting and therefore reducing the space between each coffee particle. Consequently, if the flow rate is too slow, then the grinder is adjusted to a coarser setting, opening up gaps to reduce resistance.
Entry-level domestic coffee grinders only have a limited number of grind settings and so are not ideal for espresso making. To achieve the correct flow rate the grinder needs to be capable of minuscule adjustments. If your grinder only has 10 to 15 setting from finest to coarsest, only 2 or 3 or these are going to be in the espresso range and so the grinder is not going to give you enough control over flow rate. Therefore, the best option for an espresso grinder is either one with over 30 settings or one with stepless adjustment.
A good espresso machine is not necessarily needed to make great espresso. With enough skill and a lot of luck you can pull a great shot from just about any espresso machine. However, if you want to remove that element of luck and pull consistently great shots you need a quality espresso machine. To extract the fullest flavour from the coffee an espresso machine needs to be at the correct pump pressure and water temperature. Cheaper espresso machines will fluctuate too greatly in both these areas to achieve great shots time after time.
You do not have to be World Barista Champion to make great espresso. Once you have learned the basics (see our guide) it is just a case of lots of practice and experimenting to perfect the art.
This M is often overlooked. Your espresso machine and coffee grinder must be cleaned regularly, not only to prolong their life, but also to keep them producing great espresso. The objective of cleaning is to remove all the leftover coffee grounds and oils from all your equipment. If these are not removed then they will contaminate the fresh coffee and impart a stale and bitter taste on your espresso.