What do I need to know to grind my coffee well at home

 What do I need to know to grind my coffee well at home

Although it may not seem like it, coffee is a fruit that spoils over time. As occurs when peeling and cutting an apple that turns brown after a few minutes, the small particles of ground coffee come into contact with oxygen and quickly lose their aromas and flavor.

On the contrary, coffee beans better maintain their properties and freshness because they considerably delay their oxidation. For this reason, try to buy the amount of coffee that you are going to consume after a month from its roasting date. For example, a 250 gram bag of coffee can last up to 2 weeks for me. When I go to buy coffee to grind at home, I choose a roasted one in the last two weeks.

- What do I need to know to grind my coffee well at home and Burr Coffee Grinders Product

The carbon dioxide (CO2) also plays a role in the oxidation process of coffee because it slows down. The CO2 accumulates inside the coffee bean during its roasting and is released little by little when it is finished. Once the coffee is ground, the CO2 disappears in a few minutes, accelerating its oxidation.

Coffee also contains beneficial health antioxidants like caffeic acid and melanoidin. Both originate at high temperatures during coffee roasting and, like CO2, these compounds go rancid when they come into contact with oxygen, especially if the coffee has been ground.

All that said, try to preserve your coffee beans for as long as possible. It doesn't matter what you paid for your coffee: if it has been previously ground, you won't get the most out of it. A decent coffee and a low-end manual grinder are enough to leave you with an advantage over any pre-ground coffee.

Types of coffee grinder

Commander Conical Grinding Wheel

Avoid at all costs using a blade coffee grinder to grind your coffee as it has a blade system that cuts the beans inconsistently. As a result, when we infuse the ground coffee, there will be finer coffee particles over-exposed to the water, and coarser ones that will not have been moistened enough, resulting in an unbalanced cup of coffee.

On the other hand, this type of grinder usually has a universal grinding setting and a single grinding speed. It doesn't allow you to grind for brewing methods that require specific thicknesses, as we'll see below.

Finally, the electric motor of the knife grinders tends to overheat, affecting the taste of the coffee.

In their favor, it is true that blade grinders are a cheaper and faster option to grind your coffee at home. You can buy a low-end one for € 10 and grind coffee in a matter of seconds.

The grinding wheel coffee grinders (also called strawberries), whether manual or electric, grind the coffee bean with greater precision. It allows you to select between different levels of grinding according to the production method used.

This type of grinder uses 2 grinding wheels that, when they come into contact with each other, crush the grain according to the distance between them. By producing a more uniform grind, grinding wheels allow all ground coffee particles to be moistened equally. In this way you will avoid coffees with unwanted flavors due to an unbalanced grinding.

Conical vs flat wheels

Depending on the mechanism you use to grind the coffee beans, grinding wheels can be conical or flat . In general, flat wheels are more affordable than conical ones. Both options are suitable for uniform grinding.

Finally, depending on the material used in the manufacture of the wheels, the grinding wheels can be made of stainless steel or ceramic . Both materials ensure that the grinder does not get too hot during use.

Among the drawbacks of grinding wheels is their price (from € 30); and, if it is manual, the discomfort of having to grind by hand (on the other hand it makes it more artisan).

Types of coffee grinding

Once you are clear about which grinder you want, you must evaluate another variable: what grind you will need for your coffee making method.

The thickness of the grind is a determining factor when preparing coffee. It's like putting different sized cookie dough in the oven: some cookies will come out well done, and others not so well.

In the same way, if the ground coffee particles are not consistent, or simply the grind is not suitable for your coffee machine, the coffee will come out over-extracted (bitter aftertaste) or under-extracted (sour and acid aftertaste) .

Finally, you will be interested to know that the oxidation process of coffee is directly proportional to the size of the grind: the finer the grind, the greater the effect of oxidation on the coffee. According to the SCA (Specialty Coffee Association), the contact surface of the coffee bean increases more than 10,000 times when it is ground to prepare an espresso (fine grind).

Sometimes it can be difficult to find the perfect grind. This mini-guide tries to shed some light on this matter:

1. Fine grinding

Ideal table salt texture for espresso and Italian mocha . You can grind even finer if you are a user of a Turkish coffee maker .

2. Medium-fine grinding

Slightly thicker texture than table salt, optimal for AeroPress and drip cones like V60 or Clever Coffee Dripper .

3. Medium grinding

Brown sugar texture compatible with drip methods using flat bottom filters like Kalita Wave , and siphon coffee makers .

4. Medium-coarse grinding

Coarse salt texture ideal for a Chemex filter coffee maker .

5. Coarse grinding

Texture slightly coarser than coarse salt ideal for  French press . You can grind a little coarser for cold brew coffee .

How to adjust the coffee grinder

As we have already mentioned, each coffee maker requires a different grind. Try using a fine grind in a French press, and you'll see what I'm talking about. To achieve this end, the mills have two methods that allow us to choose the thickness of the grinding: the method with scales and the manual.

The grinders with scales have a predefined grind selector to choose the one that best suits our coffee machine. There are grinders with 5, 12, 20 or more than 50 levels of grinding that usually range from a finer to a thicker thickness. In addition, grinders like Wilfa indicate the name of the coffee maker that best suits each level of grinding.

Manual grinders allow you to choose the degree of grinding by precisely adjusting the distance between the grinding wheels that grind the coffee. With no grind options, you have more freedom to choose the thickness of the grind and experiment with your coffees. However, you will need a higher command of the grinder and the preparation method you use.

What distance between wheels is the most suitable for AeroPress? In this guide  we solve this question for users of the Porlex JP-30 manual grinder.

Tricks for grinding coffee at home

1. Never buy roasted coffee: use fresh 100% arabica coffee to taste all its aromas and flavor.
2. Grind the coffee just before preparing it to avoid oxidation.
3. If the coffee has been under-extracted, and has a sour aftertaste, try grinding the beans more finely. By grinding them too coarsely, the coffee infusion has not extracted all the flavor of the coffee, that is, the ground coffee has not been moistened enough.
4. If, on the other hand, the coffee has a bitter aftertaste (over-extraction), you must grind more coarsely. In this case, the coffee particles have been soaked for longer than they should.