So, you've figured out that you need to grind your own coffee beans to extract the maximum amount of flavor. However, you've quickly learned that there's a lot more to this process than simply measuring out coffee beans and pushing a button. Hence, your need for a coffee grind size chart.
So, you’ve figured out that you need to grind your own coffee beans to extract the maximum amount of flavor. However, you’ve quickly learned that there’s a lot more to this process than simply measuring out coffee beans and pushing a button. Hence, your need for a coffee grind size chart.
Lucky for you, I’m an expert at making coffee. I’m also good at explaining things quickly, so let’s jump right in. Feel free to use the table of contents if you need to skip ahead.
Table of Contents
- Why Grind?
- Crash Course in Coffee Grinding OxidationMoistureCO2 DepletionYou're Catching On
- Choosing Grinders
- Grind By Brew Table Finely Ground CoffeeCoarsely Ground CoffeeMedium Ground Coffee
- Coffee Grind Size Chart
- Grinder Calibration
- Correcting Over and Under-Extraction Under-ExtractionOver-ExtractionMake Your Own Masterpiece
- Final Thoughts
Grinding 101: Why Grind Coffee Beans in the First Place?
A lot of people wonder why they should bother grinding coffee beans when pre-ground is readily available. Even if they kinda understand the value of using quality coffee beans, they still have their local barista do the grinding at the time of purchase.
While such beans would definitely be fresher than those which sat on a store shelf for months, they still are a victim of oxidation, moisture and CO2 depletion.
Sixty percent of coffee aroma is lost within 15 minutes of grinding.
A Crash Course in the Science of Coffee Beans
Let me grab my lab coat and I’ll explain the chemistry behind the death of coffee beans.
Oxidation is the term we use to describe the process in which oxygen in the air binds with other substances. It’s the reason for rust, aging and cut fruit turning brown. In fact, oxidation during roasting also turns green coffee beans their familiar chocolate color.
Just as the skin on an apple protects its flesh from air, the best parts of the bean are also encased in carbohydrates and proteins beneath its shell. Grinding breaks open the shell of the bean and increases the coffee’s surface area by as much as 10,000 times.
In other words, when you grind a coffee bean, 10,000 times more of the bean is exposed to oxygen in the air.
Whole beans have a measure of protection while their hard outer shell is intact. Of course, this won’t safeguard the contents forever because aromas gradually dissipate over time.
This is why coffee is most aromatic when you grind right before you brew.
Another bogeyman to watch out for is moisture. It could go without saying that coffee beans dissolve in water. But did you realize that even moisture in the air can dilute and degrade them?
What’s worse, moist beans are an invitation for mold and bacteria. Again, the increased surface area of ground beans exposes them to water vapor from the atmosphere. This moisture can then attack more of your coffee, thus leaching out its better qualities.
A third process rooted in roasting is the formation of CO2 gas inside of coffee beans. While climate science has taught most of us to think of CO2 as evil, it is a coffee fanatic’s best friend in this case.
Not only is CO2 responsible for transporting the essential oils that create the crema on your espresso, but the gradual degassing process after roasting protects delicate flavor and aroma compounds from oxidation.
You're Catching On
Yep, you guessed it. Grinding the beans allows all that CO2 to escape in minutes so that once again your coffee is at the mercy of oxidation.
There’s just no way that industrially pre-ground beans with their long distribution chains and time spent sitting on store shelves can get to you with all the good stuff still intact. Forget it.
If you’re now sitting there scratching your head over how to protect coffee beans from the elements, read my article on how to store coffee beans.
Things To Look For in a Coffee Grinder
Buying a coffee grinder isn’t rocket science. You really just need to pay attention to a few key features. Here’s a quick rundown of what to watch out for.
- The more grind increments, the better. And you definitely want more than what you get with the average super-automatic espresso machine. This will allow you to make subtle adjustments so that you get as close as possible to the perfect cup.
- Most — good — grinders are specialists. They either excel at producing fine or coarse coffee grounds, but not both. Choose one that matches your brewing method.
- Whether you’re grinding to achieve a fine or coarse grind, you want the particles to be uniform in size to reach maximum extraction. This will also prevent unwanted particles from reaching your cup.
- Go with a burr grinder. Don’t even consider a blade mill grinder. Blades hack randomly at beans as they bounce off the grinder walls and are incapable of producing a consistent coffee grind. Conical burr grinders are constructed differently from flat burr grinders, so each has its pros and cons. You’re pretty safe with both options.
To get a more in-depth understanding of these machines and discover my top picks, read my article on the best coffee grinders.
Definitely refer to the coffee grind size chart below before you purchase a coffee grinder.
Why You Need A Coffee Grind Size Chart: How Grind Size Impacts Extraction
The next piece to this puzzle is choosing the right grind size.
Finely Ground Coffee
On one end of the spectrum is ultra-fine espresso grind, where you’ll find espresso connoisseurs making minute adjustments to brew the perfect cup with their espresso machine.
Remember how grinding coffee creates a greater surface area for oxidation and moisture to attack? Well, the same thing applies to water and extraction.
The finer the coffee grind — and the tinier the coffee particles — the higher the proportion of your beans that comes into contact with the water.
Thanks to the bigger surface area, the water fully extracts the coffee in less time.
By the same token, water flows more slowly through small, densely packed particles.
When making espresso, very finely ground coffee is tamped into a compact puck to resist the pump pressure that drives the water through the coffee grinds. The force of the water penetrates the coffee’s cell walls resulting in a bolder brew.
Coarsely Ground Coffee
On the other end are cold-brew coffee makers. Cold brew requires very coarsely ground coffee that is left immersed in water — without the application of pressure — for several hours.
Stepping back from this end just a bit are users who require a suitable French Press grind size, which is also coarse.
Medium Ground Coffee
The middle ground — pun intended — is best suited to methods such as pour-over, where gravity draws the water over and between every granule.
Choosing the correct pour-over coffee grind size results in sufficient contact time for extraction of a robust brew. Harsher notes are trapped by the filter paper and you end up with a beautifully balanced brew.
Here, you will also find those using a standard or grind and brew coffee pot.
The ultimate goal is optimal coffee extraction, which best happens when you choose a grind size that matches your brewing method.
Shorter brewing methods generally require finely ground coffee, which slows the flow rate, and may rely on pressure.
As you can see, there’s a lot that goes into brewing a perfect cup of coffee or espresso. Don’t worry, the coffee grind size chart below will make everything easy to remember. I recommend you keep it saved in your bookmarks for quick reference.
|Grind size||Contact time||Flow rate||Pressure|
Chart Your Way to Better Coffee: Grind by Brew Table
Now, that you understand the broad strokes of what’s involved, you’re probably eager to get to a paint by numbers solution — in come the coffee grind size chart I mentioned.
As some of you have already scrolled down to discover, grind size recommendations are ballpark figures. How ironic that following this chart will help you knock it out of the park!
At the end of the day, your personal preferences are the most important factor. After all, this is for you to enjoy.
Just keep in mind that your choice of grinder, beans and roast will also have an impact.
I’ll dig deeper into that in a bit. For now, let me say that my coffee grind size chart lists settings ranges for my top grinder picks. Use them as the starting point for your own testing process.
Coffee Grind Size Chart
|Brewing technique||Grind size||Barzatza Sette 270Wi||Barzatza Encore||Comandante|
|Turkish||Extra-fine, like flour||1–2||1–3||5–10 clicks|
|Espresso||Fine, like finer salt||3–7||4–9||10–15 clicks|
|AeroPress||Medium-fine, like table salt||3–18||4–23||26–30 clicks|
|Moka pot||Medium-fine, like table salt||3–12||4–16||15–20 clicks|
|Pour-over||Medium, like sand||8–23||11–29||22–32 clicks|
|Drip machine||Medium, like sand||13–18||17–23||22–32 clicks|
|Chemex||Medium, like sand||19–23||24–29||28–31 clicks|
|French Press||Coarse, like sea salt||24–28||31–36||25–30 clicks|
|Cold brew||Extra-coarse, like ground peppercorns||24–31||31–40||36+ clicks|
While you’ll notice that I’ve diligently filled in a range of coffee grinder settings for each brewing method, don’t think that means each of these grinders will churn out perfectly even particles across the entire grind spectrum.
While the Baratza Sette 270Wi is my machine of choice for fine ground coffee, the Baratza Encore will save you some money and serve you better in the medium-coarse grind department.
The Barzatza Sette 270Wi sells for $599.95 on Amazon. You can get the Baratza Encore for $169.95.
The Comandante is hands down my favorite manual grinder. In fact, it’s that rare grinder that produces consistent results on all types of coffee grinds. That’s if you’re willing to put in the elbow grease, of course.
The Comandante is currently available for $444.50.
Testing, Testing, One, Two, Three: Grinder Calibration With a Coffee Grind Size Chart
So, how do you get from my ballpark figures in the coffee grind size chart to a coffee homerun? If you follow my steps, you’ll be able to go about systematically nailing flavor, whether you’re milling a pour-over grind or finely ground beans for Turkish coffee.
- Only ever adjust your grinder while its running.
- Always make incremental adjustments.
- Keep a close eye on the rate that your coffee flows into the cup.
- Repeat steps one to three until you reach java nirvana.
On everything from smartphones to the washing machine, you select the program and then hit play. So, the first step might seem counterintuitive.
Why is it important? Well, because adjusting the grinder while it’s running allows the burrs to settle into position.
Since the burrs need to find their groove, so to speak, it takes a couple of cups before the new setting really shows its true colors.
Yeah, it’s bit of trial and error. And there really is no way to skip the actual brewing and tasting before adjusting again. Darn, right?
That’s not to say you can’t spot even subtle changes in consistency from the way the grounds tumble out the chute. You absolutely can.
Think rapid landslide versus slow-moving molasses. But that only alerts you that there is a difference in grind size, not how the results will be after extraction.
You may notice after opening a new bag of beans that, despite not changing brands, roast or your grinder settings, the grounds exit the grinder a little more swiftly or sluggishly. This is the first sign of natural variation in your beans.
As a result, the grounds are actually coarser or finer. For this reason, you may need to recalibrate your grinder with each new bag.
As I mentioned earlier, your choice of roast also affects your calibration. That’s because the high temperatures not only change the beans chemically but also on a structural level.
The darker the roast, the more fragile and porous a bean’s cell walls become. Grind them too fine and that big surface area results in a flavor dump. Not a good thing.
Don’t go wrestling your grinder over the roast. We’re talking tiny variations in grind size within the range for your chosen brewing technique. The difference in coffee grinder settings between a light and dark roast is probably a single increment.
Going too fine on a dark roast will result in a bitter espresso or an odd sour note to your pour-over coffee.
How To Correct Over and Under-Extraction
Just like beauty is in the eye of the beholder, perceptions of what is delicious are on the tongue of the taster. So, once your tastebuds are doing a dance of joy, you can stop tweaking your grind settings.
On your path to creating the perfect cup, you will probably learn to recognize both flavors you love and one’s you don’t. This section is about how to adjust your grinder settings based on what you’re tasting.
With their range of molecular and chemical structures, various flavor compounds dissolve at different rates. So, if your water passes through the beans too quickly, it only takes the early bird flavors and misses out on the late bloomers.
Known as under-extraction, this is only half a party in your mouth. I don’t know about you, but half a party sounds pretty boring.
In contrast, a brew that has soaked for too long and has an excess of soluble compounds is over-extracted. In this case, the festivities in your mouth are more of a stampede at a concert. This is also not what you want.
Make Your Own Masterpiece
Think of coffee as a recipe and the compounds in beans as your ingredient list. With different grinds of coffee and brewing techniques, you’re selecting items from the cupboard to use.
The aim is to include everything in the right proportions. You’re not trying to eliminate particular flavors in an over or under-extracted coffee. You’re only trying to balance them.
The way to do that is by adjusting your grinder coarser to correct over-extraction and finer to fix under-extraction.
(Your grind is too fine)
(Don’t touch anything!)
(Your grind is too coarse)
|Dry, astringent||Rich, creamy||Lacking sweetness|
|Empty||Great, long aftertaste||Short-lived aftertaste|
Salty? Empty? No, I didn’t just lose my mind and the thread of this article in a bag of chips. Admittedly, some of these terms can be a bit deceptive — or plain confusing — so it’s worth taking some time to explain them.
Final Thoughts on Coffee Grind Size Charts
Remember, all of the adjustments we’ve been discussing here will achieve nothing if your palate isn’t clean. Whatever you eat and drink prior to your experimentation will influence how you perceive the taste of your coffee.
The sugar in soda, for example, will make coffee taste astringent. Citrus, on the other hand, will make it seem fruity.
If you’ve just had a big meal, it might be best to wait to fine-tune your machine until another day.
Appreciation of coffee is an art all of us can enjoy. I personally enjoy learning from you, our readers.
Please share your experiences with grinding, tasting and reaching coffee nirvana. That way we can grow together.
Let me know in the comments about the wild and wonderful flavors you’ve detected in coffee.