Coffee Grind - What Is the Proper Grind Size and How It Affects Your Cup?
Coffee is a versatile ingredient. The same ingredient can be turned into various drinks ranging from strong and pungent tasting to light and delicate on your palate. All these flavors can be obtained by tweaking the brewing variables such as grind size, water temperature, and extraction time. The result of these variables is the extraction, Atlin Mountain Coffee Roasters has a post about it here. A very often ignored variable in home coffee brewing is the grind size. Grind size can make or break your cup, but not for the reasons you might think. I’ll explain in a bit.
The three variables of the extraction are interdependent. If you change one variable you change the extraction ratio, which means a different cup. But at the same time, if you perfectly tweak all brewing variables in a perfect balance, you could get a similar cup. So in theory, with the same grind size, you could get the same cup as long as you tweak the other two factors - the water temperature and the brewing time. Unfortunately, this is utopic, and in practice that is almost impossible. Firstly, because it is very hard to tweak those variables to perfection. The variables we are using now in coffee making have been tweaked for years. We got to the perfect cup of drip after experimenting hour and hours. SCAA finally got the right numbers for automatic drip after experimenting and sampling hundreds of cups. Espresso has an even longer history, and there is even less to improve to the standard preparation variables.
Coffee Grind Size Recommendations
The grind size is probably one of the variables that is the hardest to tweak in coffee brewing. It shouldn’t be a problem to change the grind size. According to the physics, the finer we grind the faster we extract and the better the extraction is. This is just in theory though, the practice has shown us that, depending on the brewing method, the grind size range is very restricted. The standards for the most popular brewing methods are:
- Cold brew - Coarse
- Percolator - Coarse
- French press - Coarse
- Drip - Medium grind size
- AeroPress - Fine
- Espresso - Extra fine
- Turkish coffee - Powder
Drip Coffee Grind
A great example of why we cannot tweak the grind size is drip coffee.
Let’s say you were to tweak your drip coffee for a finer drip. And we will assume you lowered the brewing temperature a couple of degrees to compensate for the finer grind. You also need to adjust the beans quantity, since extraction will be higher. There is a parameter you can’t control with drip - the brewing time. The finer you grind, the longer the brewing time, since water will pass slower through the grounds in the brewing bed.
Now, you can tweak your cup to make it stronger if you slightly decrease your grind size. And I will absolutely encourage you to tweak yours. Experiment! But remember, you can’t use coffee too coarse or too fine. You cup will be bitter if you grind too fine, and will be sour and weak, if you grind too coarse.
French Press Grind - Can you Tweak It?
An interesting brewing method is French press. In theory, (again), it’s easier to tweak your French press coffee cup. The reason is that this is not a gravitational method, but an immersion method. This means we have complete control over the immersion time. We can also control the water temperature, (use a thermometer or a variable temperature kettle). So why can’t we choose a finer grind? The coarse grind is causing so much waste. The reason is the filter. Anything below coarse will result in a silty cup. The screen filter that equips a French press coffee maker is inherently ineffective.
To be honest, a finer grind is possible for French press. A grind size closer to drip than to percolator. This finer grind, however, requires a great grinder that will produce a perfectly uniform grind. You can also use a set of ground coffee sieves, like the ones from Kruve. Both solutions are expensive though. I played with finer grinds for French press, and I got great coffee. If you are willing to spend money on equipment you can get those too. But I suggest you save your money and spend it on better coffee beans.
What about Espresso?
Espresso grind size cannot be tweaked. You have to stick with the standards, or you’ll ruin your shot. More than that, grind size for espresso depends on the beans’ origin and the roast. In other words, you need to find that perfect grind size every time you change the beans. Once the grind size found, you need to stick to it. Too fine the grind, ond the shot will not flow, because of too much pressure in the brew head. A hair too coarse, and the shot will flow too fast, and will be under-extracted. Yes, you can tweak your espresso to prepare it for your liking, but grind size is not one of the things you can play with.
If you are new to home coffee brewing, stick to the industry standards. This way you will get a consistent cup of coffee every time. If you are experienced and you played around with coffee preparation, you can try to tweak you grind. As I said, coffee is a versatile ingredient. If small grind size changes don’t fix your cup, maybe it’s time to change the brewing method.
Guest post by Dorian