He perfect coffee It has a lot of science behind it. For example, many scientists have studied the chemical characteristics of the ideal foam. Because what would coffee be without a good foam to top it off? Likewise, grinding is an essential step, which a rather curious couple of scientists recently wanted to investigate: a materials chemist and a volcanologist.
Is about Christopher Hendonfrom the University of Oregon, and Joshua Mendez Harper, now at the University of Portland. Both have analyzed which are the ideal coffee beans and, in the process, have verified whether the habit of some coffee lovers from Spain is really useful. moisten the grains before grinding them.
As a preview, yes: to obtain the perfect coffee it is recommended moisten the grains. But how much water is needed? Is there one type of grain better than the rest? Let’s see what the conclusions of your study have been, recently published in the magazine matter.
The problem of static electricity
The biggest enemy of perfect coffee is the static electricity generated during grinding.
We have all experienced the static electricity. For example, when we touch the car door or the handrail of an escalator and feel a spark. But why does this happen?
The answer is simple. The atoms that make up matter are normally found in neutral state. That is, they have the same number of positive and negative charges or, in other words, the same number of protons as electrons. However, sometimes, when they rub against each other, they can produce an exchange of electrons, so that one loses, becoming positively charged, and another gains, becoming negatively charged. This is what happens, for example, when we rub a pen against a woolen garment and then bring it close to some pieces of paper. The pieces of paper stick to the pen because it has become electrifiedacquiring electrons from the wool, and now it can attract the pieces of paper as if it were a small magnet.
The problem is that the loaded materials, whether negatively or positively, they continue to seek neutrality. Therefore, when contacting other electrons, they tend to steal or give up the electrons they lack or have extra. This electronic transfer causes the famous spark What we feel when we touch the car door.
Now, what does all that have to do with perfect coffee? The truth is that a lot. When grinding the grains, a great deal of friction occurs between them, which is why static electricity is inevitably produced. This causes the grains to clump together and even clog the grindercausing a lot of waste and inefficient obtaining of coffee aromas.
Scientific tricks for a perfect coffee
Static electricity is usually higher in a very dry environment. Therefore, there is a tendency to moisten the coffee before grinding itto avoid it as much as possible.
These scientists wanted to check to what extent this is necessary to obtain the perfect coffee. And, to do this, the first thing they did was get a bunch of coffee beans of commercial origin and roasted in a laboratory, which varied in their origin, roasting times and moisture content. After, They measured static electricity in each batch after grinding, as well as the particle size of the freshly ground coffee and the flavor of the final preparation.
By grinding the coffee twice, they found that most of the static electricity does not come from the friction between the beans, as initially thought, but from the rip thereof. They also saw that the effect was greater with darker and drier grains, compared to the lighter ones. It is not clear what this may be due to, but the authors of the research suspect that it is because the more roasted beans are more fragile than the lighter, less roasted ones, which still retain some of their moisture.
Indeed, humidity is the key
Given this, it was clear that humidity is important, as had already been postulated. Therefore, the next step of the experiments consisted of moistening the grains with different amounts of water and checking the static electricity generated in each case.
Thus, it was seen that, to obtain the perfect coffee, you must add 20 microliters of water for every gram of coffee. That is, half a milliliter for a typical cup of espresso.
What does a volcanologist have to do with perfect coffee?
One may wonder why one of the authors of this research on the perfect coffee is a volcanologist. And, in reality, coffee grinding has quite a relationship with volcanoes.
In fact, the lightning bolts that are often generated by volcanoes do so by the spark of static electricity generated by rubbing dust particles into volcanic plumes. Furthermore, with this study it has been seen that the charge/mass ratio of coffee beans is similar to that of the dust particles of these feathers.
Therefore, this study on coffee can also be applied to geological sciences, when carrying out predictive models on volcanoes, but also on landslides or water seeping into the ground. It is much more than a perfect coffee; Although, for now, with this research we can now prepare a cup of the best espresso.