The Perfect Espresso
By Manuel Terzi.
Is there a way to make coffee better than others? Strictly speaking the answer is no, since there are different tastes and expectations. There are , individual national cultures, and different geographic areas in which coffee is consumed so it is better to say they are “different” and not “better”.
However let us explore the the classic Italian tradition of the morning espresso consumed at the the Italian bar-café as the place where the espresso drink and cappuccino were born and perfected. We can discover that the preparation carried out “professionally” must be respect ed because the preparation followed specific rules using precise criteria. The result of this practice and tradition is based on a passion culture that has very few equals in the world. Espresso and cappuccino are today an extraordinary and growing international success but to be considered “authentic” espresso and cappuccino, one must respect and seriously follow the implementation of certain essential rules of preparation.
A perfect espresso as reiterated by many associations such as the “Italian Espresso National Institute” and the “Association of Teachers and the Speciality Coffee Association of Europe” must conform to the following specifications . The dose of ground coffee should be -7.5 6.5 grams, the pump pressure must bebetween 7.5 and 9 atmospheres, the boiler must be 0.8atmospheres -1.2; the water temperature measured at the group, to be 88-96° C; to produce in a time of 20-30 seconds, a volume of between 20 and 30 ml.
As you can see, for each parameter that we can actually have a wide range of values. This means you get the best possible drinks you should move within a range of virtually infinite combinations.
If we try to draw a multidimensional graph that would take account of the parameters described above would get some kind of space in which each dot represents a potential perfect espresso. There are so many possibilities to interpret what we can call “perfect espresso”, starting from the raw material (natural or washed coffee mixture, mono-mono-source origin, decaffeinated) until you get to the various possible combinations of all the parameters for its optimal extraction.
To determine the best extraction, in addition to the type of coffee, you have to consider many other factors, such as the harvest than roasting, roasting times, the type of process after harvesting, listing olfactory taste you expect, use if to blend or pure source, the type of customer, the location of the glass or where the coffee will be consumed, the degree of roast, and we could continue. Just knowing this data, and the processing of grains in the drink, the best qualities of a particular coffee will be revealed and appreciated.
There is no “best” coffee. Each type, origin and harvest has distinct features and advantages, which can be enhanced by an appropriate extraction.
If there is no ideal coffee quality, is clearly not possible to adjust the equipment once and for all; There is no “perfect universal setting.” It will be necessary to change the settings and adjust all the parameters of the equipment employed, taking into account the particular type of coffee you want to use, and observe strict rules of operation. Only in this way can the quality of the coffee will be valued at the maximum.
If you ask a winemaker as the best wine is produced, difficult to geta clear answer, and much less comprehensive. He explained that countless varieties of grapes, vilification techniques … Not to mention the human and cultural context which a particular wine is an expression. With the coffee the same thing happens: the washed Arabica, Arabica, Robusta, Robust washed Monsooned, decaffeinated, blends, light roasted coffee, dark coffee roasting, coffee crisp, ripe coffee….
To confuse things further, there is the fact that there are virtually no preparation specifications in which torre factors and bartenders must abide by, I mean everyone can do what they like without giving too many explanations … then, in the expectation that a specification is defined (such as those that exist for many other foods), the Act of buying a coffee espresso – be it , for Moka, makeror any other method of preparation – it’s good to inquire about its peculiar qualities, and how to exploit them to the fullest.
Can be helpful some indications about our beloved espresso extraction.
With coffee Robusta species – which, as we have seen, are characterized by high sciropposit
With coffee Robusta species – which, as we have seen, are characterized by high viscosity – you can use a rather energetic extraction, then around 8.5 bar -9 at the pump, with the water temperature also group 92-95° C and boiler set at 1.1 bar -1.2. You can also increase the weight up to 7.5 grams -8: this probably won’t change the taste-olfactory sensations; being a poor coffee Robustain terms of taste and smell, won’t give much, but can improve thosegestures, i.e. the creaminess, only feature in which they can appealthe Robusta. Such an approach is also suitable for mixtures with a high percentage of Robusta, or-for different reasons-in the case offresh coffee roasting. A draw would be rather unfortunate for coffee washed Arabica, much more delicate and aromatic hydrocarbons, which would inexorably burned and flattened, which is deprived ofthe most volatile aromas, and simultaneously become too intense, up to be ungainly and, as they say, “out of tune”.
With the Arabic you will have to opt for a lower pressure boilers (-1.1 0.9 bar) and a lower pressure pump (around 8 bar); also the water temperature to the Group should be lower (never exceeding91/92° C) and you must be careful not to exceed the amount ofcoffee; If the quality is good, you don’t need 10, 11 or 12 grams (asCoffee Master lately in some countries want us to believe):
7 grams are more than enough. With a mountain washed Arabica,maybe centroamericano, 6.7 grams -6.8 will give one espresso elegance, harmony and amplitude, features that you could lose withlarger doses.
I mean, it’s easy to see how the work of the engineer, who has the final transformation of ground coffee in the espresso itself, both among the most important variables of the entire production process. A somewhat delicate task: an imperfect, marred by even trivial errors could nullify all the work done previously by introducing procedural errors by the tragic repercussions, while in no case may make improvements: the result to strive for is to not introduce errors in the chain!
After their set almost all variables (weight, machine setup, equipment maintenance, timing and volumes of extractions), there are only few but very important precautions.
And oils of roasted coffee colloids tend to react with the oxygen in the air; the more extensive the surface exposed to oxidizing agents, the faster the oxidation process, also accelerated by changes in temperature and exposure to light. Then this process is accelerated before the coffee comes to oxidation, Rancidity, and then at the end of his life. For this reason it is advisable to keep roasted coffee beans, and always set aside at the last moment the grinding operation by which you multiply the surface area exposed to risk of oxidation, and favours the dispersion of aromatic substances essential for L’Espresso and for each type of coffee drink. Furthermore the ground coffee tends easily to acquire foreign odours and moisture (being extremely hygroscopic). The extraction technique should take into account everything, compensating for any changes through the coffee grinding regulation, which as it turns out must be carried out only at the time of the draw. Once you set the other parameters, is the right particle size adjustment to ensure that in 20-30 seconds – duration considered optimal extraction – the machine produces a quantity of drink 20-30 ml. In General, the grind should be finer if the espresso drops in a (too) short time. And vice versa in the opposite case. Another important adjustment is that of Coffee pressing.
The passage of water through the coffee pod takes place with a very high thrust, IE 7.5/9 bar; pressing should then lead to a compact waffle not present preferential pathways for water, and should be done by force, with a hand tamper (for better control on parallelism of upper and lower faces of the coffee pod) of the same size filter (to not leave the edges not pressed powder, and then extracting untapped ,); the operation must be carried out after tapping the filter holder with the same pusher in order to better distribute the dust, and with a slight rotation of the tamper to optimize the compression of the coffee pod. The effective English expression: Tap, Tamp and Twist, or tap, and press the wheel.
Before proceeding with the extraction, it is good to make a short, or flushing activate the group for a second when the arm is still attached to the group to remove residual dust remaining on exhausted hand shower; With the attachment of the boom to the group, the coffee powder in the filter which is located is exposed to high temperatures (the group is hot) and high humidity (on the hand shower): a hazardous environment for the coffee: it is therefore necessary to proceed with extraction immediately, in real time as soon as the arm was attached to the group. The optimal extraction time, between 20 and 30 seconds as we have seen, will vary due to the type of coffee used, the size and environmental conditions.