Different grinds for different extraction methods

ernani-coffee-professional-grinder

Grinding is one of the essential cornerstones for extracting an excellent coffee, but it is too often underestimated or even ignored!

So: how should the coffee be ground?

The answer is only one: there is not only one answer!

Yes, because the grinding is not unique for all extraction methods; it also varies with changing environmental conditions.

The importance of grinding

Before starting, you need to understand why grinding is important:

  • It influences the extraction and color of the drink;
  • It influences the taste and aroma in the cup;

We also grind because:

  • The aromatic substances, created during roasting, are trapped in the cells of the coffee bean. With the grinding we segment the grain into very small parts. In this way the water, during extraction, has the possibility of hitting many more cells, breaking the "barriers" and thus releasing the aromatic substances;
  • To increase the extraction surface. In fact, by grinding we have already said that we segment the grain into thousands of smaller particles. In this way the water can "touch" a larger surface of the grain and therefore extract more substances.

Different grinds for different extraction methods

Now that we understand the importance of grinding, we need to understand how to grind coffee!

Each tool used for the extraction of coffee has its own specific granulometry level, i.e. the thickness of the coffee powder obtained.

  • The degree of grain size depends on:
  • From the temperature of the water used for extraction;
  • By the pressure exerted on the ground dough;
  • From the type of extraction, that is: percolation, pressure or infusion.

Let's make a practical and concrete list right away to understand the right grind for each extraction tool used:

  1. For Cold Brew and French Press we will use a large ground coffee, similar to coarse salt. If we want to be precise, the size of the ground particles must be between 800 and 1000 microns;
  2. For Chemex, V60 and Clever, a medium-large ground, similar to fine salt, will be used. The size of the particulate must be between 500 and 700 microns;
  3. For the Mocha pot, Siphon and Aeropress, on the other hand, a medium ground coffee will be used, similar to fine sugar. The particle size must be within the range of 400-600 microns.
  4. For the Espresso we will use a finely ground, similar to icing sugar, between 200 and 300 microns.
  5. Finally, for the Turca you will need very fine ground coffee, under 200 microns.

PS. 1 micron is equivalent to 1000 millimeters. There are special tools to check the granulometry, but more simply a visual check is carried out.

We must now learn to assess at a glance whether that specific ground we have at hand is correct or should be changed.

Small clarification: the grinding is not fixed!

Let me explain: the coffee that we ground yesterday and it was perfect, it is not said that today it is still good. It is true, however, that for most of the methods very small variations in ground size do not determine a striking worsening in the extraction phase.

However, this rule must be kept in mind for Espresso. In fact, the only way to extract an excellent espresso is to have a perfect grind for that moment.

Visual check of the correctness of the grind

The basic concepts are the following:

  • If the coffee is ground too wide, the drink will go down faster;
  • If the coffee is ground too finely, extraction will be slower, or even not at all.

Because?

If the powder is too fine, it will be very compact and there will be less space for water to pass between one grain and another. The latter will therefore find too much resistance and will remain in contact with the coffee for a long time. Given the high temperatures of the liquid, around 95 ° C, the coffee burns.

Result?

The coffee will be over-extracted, therefore bitter and with an empyheumatic taste, i.e. burnt.

In reverse:

If the powder is too large, there will be much more room for water to pass between the ground grains. The latter will not find any resistance and will complete the extraction very quickly.

Result?

The coffee will be under-extracted, therefore watered down, not very aromatic, more acidic and astringent.

So: if the water passes too quickly we have to tighten the grind; on the contrary, if we see that the water does not go down, we will enlarge it.

Let's explore the methods of coffee extraction

Espresso

The espresso machine works under pressure, so the water must find a strong hydraulic resistance given by the ground dough. This is why a very fine grind is used and the ground itself is well pressed before extraction.

It is said that the extraction is perfect if the coffee descends in “rat tail” shape, that is, a wider linear thread above and finer below.

Filter coffee

In almost all filter coffees with manual extraction, no pressure is impressed, other than atmospheric pressure, except for the Aeropress.

They are distinguished in infusion and percolation:

  • French Press and Clever are infused, as the coffee remains in contact with water for the entire extraction time, or almost, just like with tea. For this reason a larger grind is required, as no resistance is needed. In addition, the extraction time is long, so the larger ground is useful for letting the water penetrate the grain of ground slowly, otherwise there is a risk of over-extracting it;

  • V60 and Chemex, on the other hand, are percolation methods, as the water passes through the ground coffee and the drink is then collected in an underlying container. Here the ground must impose a minimum of hydraulic resistance to the water, which otherwise would run away too quickly, making the drink under-extracted and not very aromatic. In this case, the extraction times are between 2 and 3 minutes: if the drink is ready in less than 2 minutes it means that a finer grind will be needed, on the contrary if it takes more than 3 minutes, a larger grind will be needed.

Mocha pot

With this method, the pressure is that of the steam which, once reached 100 ° C, pushes the water through the coffee stick to settle in the upper tank.

The ground coffee must impart a minimum of resistance, again in order not to let the water pass too quickly and thus make the drink under-extracted.

At this point you just have to choose the coffee that suits you best and buy it ground for the extraction method you want.

DISCOVER THE PERFECT COFFEE FOR YOU >>

I hope this article was useful to you, if you still have doubts write me an email at shop@caffeernani.com or a whatsapp message at +39 3756879940.

Martina Mazzoleni 

The best coffees, roasted to perfection and delivered where you want

Read more