How You Grind Your Coffee Affects Your Flavor Experience

Depending on your perspective, coffee is either a necessary, legal drug crucial to brain function, a sacred morning ritual or both. When you’re ready to take your caffeine consumption to the next level, it’s time to reconsider your coffee grind.

Sure, it’s hard to care about the perfect grind when you’re blearily making coffee at six am—but maybe it’s time to start. Once you know how to grind your coffee properly, you’ll be able to do it on autopilot.

Here’s why the grind matters.

The science behind your morning brew

Coffee can have a lot of different flavors. When it’s brewed properly, you might get hints of bread or chocolate. It can be mellow and smooth, or strong and bracing—but when you brew it improperly, you run the risk of sour or unpleasantly bitter flavors.

When you brew coffee, you’re extracting soluble flavor compounds from the coffee beans. The key to a great cup of coffee is extracting just the right amount of flavor. Under-extracted coffee is sour, while over-extracted coffee is bitter. That’s where the grind size comes in.

Think of coffee grounds like soil. If you water a plant in loose, rocky soil, the water will flow through the soil quickly and drain out the bottom. Conversely, if you water densely-packed soil with smaller granules, the soil holds the water a lot longer. Coffee works the same way: smaller particles hold more water, which means more time to extract the flavor compounds.

Therefore, if your grind is too coarse, you’re more likely to have sour, weak coffee—and extra-fine grinds will extract too much flavor, leaving your cup of joe bitter and too strong.

Depending on the type of coffee you’re drinking, you may need to adjust your grind. (We’ll get to that soon.) Water temperature, brew time and tamping down espresso shots can also make a significant difference on your coffee flavor. We suggest starting with the perfect grind, then moving on to other adjustments. The grind size will have the biggest impact on your everyday coffee.

Burrs vs. blades

The grinder you use also matters. There are two different types of coffee grinders: burr grinders and blade grinders.

Blade grinders are the most common household grinder. They operate similar to food processors, with small rotating blades. The problem with blades is that they grind the coffee unevenly, so you won’t get a uniform grind. Plus, the blades can generate heat, which also affects flavor. You might end up with a cup of coffee that’s somehow both sour and bitter.

Burr grinders send coffee beans through two rough discs, called burrs. These discs crush the coffee beans uniformly, since the grind size is determined by the distance between the two burrs. Burr grinders come in hand-cranked, electric flat and electric conical versions.

Coffee grind guide

Now that you know the science of coffee grounds, here’s an easy guide to which size grounds work with each coffee type:

• Superfine: Superfine grounds have the consistency of flour. This is best for ultra-strong Turkish coffee.
• Fine: Fine grounds should look like regular granulated sugar. Use a fine grind for espresso shots.
• Medium fine: Medium fine grounds are great for moka pots, pour-over cones, siphon presses and Aeropresses. The grind size should resemble regular table salt.
• Medium: Medium grinds are the size of beach sand, and can be used in a Chemex or drip coffee maker.
• Coarse: Save a coarse grind for French presses and percolators. The coffee grounds should look like coarse sea salt.
• Extra coarse: Finally, your extra coarse grounds should look like rock salt. Use these for cold brew, which allows about eight hours to extract the flavor.

Remember, the water temperature, brew time and tamping technique can also make a big difference—but grind size is the most important component to master. If your coffee is too sour, try a finer grind. If it’s too bitter, adjust it for a coarser result.

Coffee snobs will remind you to always grind your coffee seconds before it hits the hot water for best flavor, but that’s not always practical. Whether you’re buying pre-ground commercially available coffee or you have your hyperlocal fair trade coffee ship barista grind the beans before you head home, remember that a medium grind is standard. Most Americans use drip coffee makers, so keep that in mind when you’re choosing your next brew.

With a little experimentation, you too can have the perfect cup of coffee—even if you’re not fully conscious while you make it.