How to serve the perfect espresso. It’s not difficult but most points listed below are either missed or badly presented. Pay attention to them and you’ll go a long way towards producing that elusive cup of “perfection”. Applies equally to professional and home brewing.
1. The coffee beans must be freshly roasted. Seems obvious but frequently neglected. Coffee in its raw state will last pretty much for many months before a noticeable deterioration in taste is observed and even then, not much. After roasting the animal becomes decidedly more fierce! As a consequence of the chemical changes that occur as a result of roasting, water & oxygen attack water very aggressively indeed. Roasted beans (without protection) will become progressively stale after only a couple of days, and very noticeably so after one week. Coffee beans protected in a sealed bag (NOT vacuum packed or gas flushed) should be used ASAP after opening the bag.
2. The grinder must be clean and properly adjusted. Remove all old ground coffee (yesterday’s is too old) from the doser and clean with a dry cloth or brush.
3. The coffee must be freshly ground for each order. This can be contentious as some trainers maintain that coffee can be ground on a “top-up” basis and others say to only grind each cup as required. The answer is that in busy places topped up grinds will be used very quickly so that’s ok but at times of slow service, 10 grams can hang around for perhaps over an hour – too long.
4. The water-filter system must be in good order. This one will make some of you scratch your head in confusion since a large majority of establishments will not go to the expense of installing a water treatment system except to protect the espresso machine from harmful limescale build-up. Believe me, the water quality in Ireland and UK is not great and in most cases will greatly benefit from an activated carbon filter to remove chlorine and some solid particles.
5. The espresso machine must be set at the correct operating temperature and pressure. As most machines have a common water & steam boiler, setting the boiler pressure to approx 1.25 bar will mean that the temperature is correct. The water pressure at the pump (a separate thing altogether) should be set at between 8 – 9 bar.
6. The Barista must have knowledge and proper training! Very important. See the Barista Training section at the front of this website.