When café Adelaide preparing coffee and without getting into very technical topics, we consider certain variables: water-coffee ratio, water, water temperature, preparation method and grinding. A few days ago, someone asked me; How fine is fine? And the truth is, it depends. It depends on the coffee maker, the coffee, the roasting, the freshness, the grinder, the filter, the proportion, etc.; yes, it seems like many things to consider regarding the appropriate grinding threshold. Still, I will show you how this variable works in this blog. If you think about it, “How much is a little?” Let me tell you that a little bit goes a long way in impacting your preparation and, consequently, your drink.
Coffee grinding consists of fragmenting and reducing the structure of the coffee bean into thousands of particles, thus achieving the amplification of the contact surface of the coffee with the water and increasing the extraction capacity of the water on the grind.
If you are a regular coffee consumer, you have heard that it is advisable to grind your coffee before preparing it. Before investing in more coffee makers or accessories, it is prudent to do it in a good grinder, but where to start? I’m not lying when I say that I understand that feeling of confusion; it happens to me every time I consider investing in an electronic device.
SO… WHAT AM I LOOKING FOR IN MY MILL?
- Rundle street mills: these mills have blades that ”cut” the coffee beans into pieces. From this grinding, you can obtain very coarse and very fine particles. Rundle Street coffee and refreashing drinks are cheap, and surely many of us have seen or used one; however, our preparations can be seriously affected by not offering uniformity in the grinding.
- Burr/burr mills: these mills grind the coffee beans instead of cutting them, and in this classification, we have two subdivisions, one by the shape of the grinders, flat or chronic, and the other by the material; ceramic or stainless steel. Let’s start with the form.
- Flat burrs use centrifugal force to propel coffee beans toward the teeth. Although these wheels are cheaper than conical wheels, they must be changed more frequently.
- Conical wheels give you greater grinding speed and precision, and the threshold for changing parts is almost triple that of flat wheels.
AND THE MATERIAL?
This is important because thermal conductivity largely falls on the material. If there is something we must avoid, it is that during the grinding process, the grinder becomes hot enough and thus begins to heat the coffee, altering its properties.
- Ceramic has a lower thermal conductivity and, therefore, takes longer to heat up and cool down.
- Stainless steel heats up quickly but cools just as quickly. In addition, it is a more resistant material.
THE MEASURE AND ITS GENERAL USE
It is common to see that grinding is classified as fine, medium and coarse, each including various . In this, a range of fine, medium and coarse according to the purpose sought to be obtained in the cup. The basic principle in this is the following:
- Medium grinds: home electric coffee makers use a grind that allows the water to pass through without generating much resistance but does not allow the water to pass through very easily, considering that the extraction is automatic and the dripping is constant. This grind is very coarse for coffee makers like a moka pot because, in this case, the water would pass through extremely quickly. This grind is what we know as “standard” because even manual drip coffee makers work well with this degree of grind.
- Coarse grinds: These are regularly used to prepare a French press just to prevent too much sediment from being left in the cup. They rarely use grinds unless the coffee requires it since the flow of water through the coffee occurs quickly, running the risk of having watery cups.
But how do you measure fine, medium, and thick? We commonly use tactile and visual reference, so very fine grinds are similar to powdered sugar, medium grinds to brown sugar and coarse grinds to salt. In slightly more technical terms, grind is measured and classified in microns:
- Below 400 microns: extra fine for espresso and moka pot
- Between 400 and 700 microns: fine
- Between 700 and 900 microns: medium
- Above 900 microns: coarse
HOW DO I DEFINE THE PROPER GRIND?
Suppose we already have a grinder at home or a clearer way of ordering ground coffee at our trusted bar; how do we know it is right? This depends on multiple factors, especially our coffee, as I mentioned in the intro of this blog. Whether the coffee is fresh or not, its process, its qualities, etc., the only way to arrive at your “right” grind will be through experimentation and knowledge of your coffee, your tools and your taste. However, I leave you some tips to guide you:
- Set your standard: according to your grinder, your coffee and/or your coffee maker, establish a margin of grinds, your safe zone to calibrate your recipes.
- Roast Color: If your coffee’s roast color is towards the light, go towards the fine in your grind range, and if the roast is towards the dark, go towards the coarse.
- Perception in the mouth: if, when preparing your coffee, you perceive a little bitterness or the need to drink water (dryness), you are likely grinding finer than necessary and if, on the contrary, when drinking it, you perceive that it lacks body, flavor, and It feels watery, which means the grind is too coarse.