How Coffee Grind Size Affects Flavour – A Guide from My Mug to Yours

Hi, Adriana here!

Yesterday, we had one of our Coffee Experience Sessions at the roastery, and we honestly enjoyed it so much. 
It was so good to see everyone who came out—we roasted a fresh batch together, cupped some coffee varieties and processes, and just spent time talking coffee.

There were great questions that came up—including one that inspired this very blog post (which, let’s be honest, I was already a little behind on writing 😅).

“How does grind size actually change the flavour in your cup?”

Your coffee grind is like your brewing secret weapon.
It controls how quickly water flows through your coffee grounds and how much flavour is pulled out during that brew time.

When the grind isn’t quite right, the timing gets thrown off—and that’s when things go sideways.

• Too fine → the water flows too slowly → the coffee over-extracts → it tastes bitter and harsh.

• Too coarse → the water flows too quickly → the coffee under-extracts → it tastes sour, flat, or watery.

That’s why each brewing method needs its own grind size—because every brew has a different water contact time.

But why does the brewing method affect the extraction time?

Each brewing method controls how the water moves and how long it touches the coffee grounds. Some methods hold the water and coffee together for several minutes, while others move the water through quickly, sometimes in just seconds.

* Immersion methods like French press and cold brew fully soak the coffee in water for a long time → so you need a coarser grind to slow down the extraction and keep it balanced.

* Gravity methods like pour-over, Chemex, and drip machines let water drip steadily through the coffee → so you need a medium grind to match that flow and give the water enough time to draw out the flavours.

* Pressure methods like espresso and Aeropress push water through quickly under pressure → so you need a finer grind to make sure the water can still pull out all those delicious flavours in just seconds.

 

Does the Roast and Bean Variety Affect the Grind?

Yes, but just a little—it’s more of a fine-tuning step, not a major adjustment.

This is mostly for my perfectionist coffee friends who love dialing in every cup. You know who you are. 😉

• Darker roasts are more brittle and tend to shatter into smaller, finer particles more easily.

• Lighter roasts are denser and usually grind a little coarser, especially in manual grinders—they resist breaking down as quickly.

But wait... here’s something fun:
Even the coffee bean variety, altitude, and processing method can make a small difference.

• Higher altitude beans are denser and harder. They often need a slightly finer grind setting to extract well.

• Lower altitude beans are softer and less dense. They break down more easily and may need a slightly coarser grind setting.

• Naturally processed coffees can sometimes grind a bit unevenly because of slight variations in moisture content. They often behave like lower-density beans—breaking down faster and occasionally needing small grind adjustments.

For most brewing styles, this isn’t something to stress about, it’s usually most noticeable when you’re pulling espresso shots or chasing that perfect pour-over flow.

The Secret: Let’s Make It Yours

Here’s the real secret: we believe coffee is personal.
Some beans, some roasts, and even your own taste might inspire you to experiment. With the right information, you can start making small tweaks to discover your perfect cup.

⭐ Maybe you’ll fall in love with a slightly longer French press brew.
⭐ Maybe you’ll prefer your pour-over just a little quicker for a brighter, lighter sip.

That’s the beauty of coffee—it’s part science, part art, and always a little bit of you.

Want to have some fun and learn more about your coffee?
Join our next Coffee Experience Session! Roast, cup, and chat with us at the roastery. It’s a great way to learn, taste, and enjoy coffee together!

If you ever have questions or love geeking out on coffee like we do, we’re here.

Brew boldly. Live fully.
Adriana