Grind Size and the AeroPress

We don’t experiment with grind size as much as we could and should. This is mostly because our brewing methods’ optimal grind size is usually set in stone: You wouldn’t try a coarse grind with your espresso machine, neither would you try a fine grind in your French press.

And it’s no wonder. Most brewing methods are only ideal for one and only one very specific type of grind. For example, espresso makers require fine grinds, medium is preferable for filtered coffee and the paperless French press will use a very coarse grind. The AeroPress is different and can actually accommodate any and all types of grind sizes without compromising the quality of your coffee.

How to choose the right grind size

As it happens, the type of grind size you use will also affect the amount of water you use while brewing. It will also either shorten or lengthen the estimated brew time. But most importantly, a different grind size will yield different flavor and aroma. So, how do you know which grind size you want?

Well, we can’t tell you what you like and what you don’t. Only you can do that. There’s an AeroPress specific cupping method, which turns your AeroPress into a cupping bowl. It works by brewing using the inverted method but leaving it inverted with the filter cap off - you wait until a crust forms -about 5 minutes- and then proceed to taste just like a regular cupping. The downside is that it only allows you to taste one kind of coffee at a time. That’s why we have come up with a special tasting method for you to quickly find out what kind of grind does it for you:

Note: Grind size will be measured from 1 to 10, 1 being the finest possible grind and 10 being the coarsest.

1. Prepare three separate helpings of coffee: the first, 30 grams of 8/10 coarse grind coffee. The second, 20 grams of 5/10 medium grind coffee. Lastly, 15 grams of 2/10 finely ground coffee.
2. For the first one, prepare 100 grams of water at 85°C (185°F) and add 50 grams first. Allow 30 seconds for it to bloom, then add the rest of the water. Let steep for two minutes, the press down.
3. The second one will need 80 grams of water at a slightly higher temperature; 90°C (194°F). Pour half the water, wait ten seconds, then pour the rest of the water. Let steep for one minute, then press down on the plunger.
4. For the last one, we will use only 50 grams of water, although we suggest watering it down after extraction. Water must be at 96°C (205°F). Pour all 50 grams of water, stir for ten seconds, then press down on the plunger.

Grab your notebook. Begin by slurping each cup and jotting down which one you liked best and why. Slurping is very important: Our sense of taste is limited on the tongue, while in the back of our throats, we pick up many more nuances thanks to our sense of smell. So don’t be afraid to make a ruckus, and slurp away. It’ll help you taste better. Remember: This is how the pros do it! You may also smell and sniff the coffee and write down the differences in aroma.

Once the coffee has cooled down a little, begin a second round of tasting, and take a sip of each cup separately. Let each sip flush around in your mouth; Don’t just swallow it right away. Take your time to really taste each sip. Jot down your thoughts and opinions.

Last but not least is the cold inspection. Wait until your coffee has gone cold, then take a sip of each. You will find that it tastes very different this time and, since most of the aroma is gone by now, you get to focus on other qualities of the coffee. Is it acidic? Does it taste a little too plain compared to the other two? Does it feel too watered down?

Drawing conclusions

Once you’ve done all your writing and tasting, you have to actually sit down and think about what you wrote down. We resort to writing down because what we remember the most are first impressions and, while upon sipping one particular coffee you might have felt the fireworks, that doesn’t mean that particular grind size was better overall.

And, as we said in the beginning of the article, it all comes down to personal taste, preference, and whatever you might feel like calling it. It’s a very personal matter; You might think one particular coffee’s taste is abhorrent, yet that same coffee is someone’s favorite and they drink it every day. It is important to cast out any preconceived idea about how coffee is supposed to taste. Instead we can all agree to hate cilantro because that stuff is disgusting.

Finally, this taste is mostly for black coffee. If you’re more of a latte person, then you must adapt the taste test accordingly; Add milk and/or sugar to each recipe, as it is hard to accurately predict how a particular brew will work with milk. As with black coffee, try your latte hot, warm, and cold.