What is the best coffee grind size for a Moka pot?

Moka pot with coffee beans on dark background.

Are you a coffee lover looking for a premium coffee via moka pot? This method uses natural pressure and steam to brew coffee. The result, when done properly, is a rich, aromatic cup of coffee that falls somewhere between espresso and drip. The secret in the perfect moka brew lies in acquiring the correct grind size of coffee bean.  

A moka pot requires a medium-fine grind for the best quality brew. This is generally a little finer than rock salt and a little coarser than table salt. It should be finer than drip coffee grinds, but not as fine as espresso grinds. 

Why is this the best size?

A medium-fine coffee grind is the right size for a moka pot because it allows the most effective and efficient level of extraction. The ideal grind produces the most flavor without being offensively bitter, sour, salty, oily, or dry. 

Why does grind size matter?

Grind size matters because it is very easy to make a poor cup of coffee when using a moka pot. The moka pot has a reputation of brewing bitter coffee. Instead of the water trickling down into the grinds via gravity like in a drip coffee, water boils at the bottom chamber. When the pressure builds, water pushes up through the valve, extracting complex flavors and compounds through perfectly sized grinds, and eventually deposits the liquid into the top chamber, bubbling like a fountain. Timing and consistency is everything. If you consider yourself a coffee aficionado by any means, grind size is crucial to maximizing your coffee experience.

A general guide to coffee grind size

Here’s a general guide to determine how finely or coarsely to grind your coffee beans. If you’re stepping into the fabulous world of coffee brewing, consider grinding your own beans. If you aren’t already grinding your own coffee beans, this is your sign. 

Why you should grind your own beans

Freshness. Coffee contains oils that react with oxygen, carbon dioxide, and moisture once it is exposed. Keeping coffee beans whole will ensure maximum freshness from your brew. Your beans should stay whole up until the moment you choose to grind and use them.

Control over variables. You’ll have better control over the amount of contact time with water your grinds are exposed to as well as the flow rate of water that passes through it. 

Flavor. Once you can get grind size to the most efficient level, then and only then will you be able to experience the full potential of each coffee’s flavor profile.

Versatility. Grinding your own beans allows you to experiment with various types of brewing methods more effectively. Having premium coffee becomes way more accessible. 

What kind of grinder should I use?

Blade grinders. These are the more affordable option, you’re really on a budget. A blade grinder will render your beans irregular in size, making your brew inconsistent. Simply put, it is the wrong tool for premium coffee brews, which is the whole appeal in using a moka pot. If you can avoid it, I highly advise against using a blade grinder if you choose to brew in a moka pot.

Burr grinders. Coffee beans are passed through two revolving burrs that grind against each other. Burr grinders are superior to blade grinders because of their ability to consistently produce uniform grinds. There are two types of burr grinders:

Conical burrs are made up of two cone shaped rings. The main advantage to these grinders are that they are quieter, cheaper, and remain cooler than the second type of burr grinder which brings us to…

Wheel burrs. They are also sometimes referred to as flat burrs. Wheel burrs are the most expensive option, and arguably the best option. These are arguably the best at creating uniform particles. These are most often used commercially.

Manual grinder. These typically work by turning a crank; the longer you crank, the finer the grind size. The main advantage here is that they are very quiet and don’t need a power source. 

What are the problems with using the wrong grind size?

If your grinds are too fine, you could over extract your coffee. This will leave you with dry, bitter, empty coffee. If your grinds are too coarse, you could under extract your coffee, leaving you with sour coffee without any sweetness. 

How do I adjust grind size?

Adjust according to taste. If your coffee is too tangy, acidic, sour, or even salty, grind your beans more. If your brew ends up being too bitter, perhaps leave them a little more coarse. Of course, this is subjective. Trial-and-error is your best friend here. 

Why is moka brewed coffee so appealing anyway?

A moka pot is as close as you can get to an espresso without actually buying an espresso machine, making it both affordable and luxuriously delicious. The beauty of the moka brew is in its depth and richness, without the need for a large, clunky espresso machine. You can make it over any heat source, making it extremely versatile to brew. 

Could you buy pre-ground coffee for a moka pot?

You could, but remember: if the grind is too large, which most available drip coffee grinds are, you could end up with a dismally unpleasant cup of coffee. Additionally, coffee contains oils that react with oxygen once it is exposed. That means once you open that bag of pre-ground coffee, you’ve begun the reaction process. This reduces the freshness of your grinds, and thus the quality of your brew.


Coffee should be full of enjoyable personality. A great moka brew will leave you with a full-bodied, flavorful, aromatic, balanced, and sweet cup of deliciousness.  If you’ve acquired medium-fine grounds, accounted for variables, and know your flavor preferences, expect to taste one of the best cups of coffee technology has to offer. If it doesn’t come out perfect the first time, don’t worry. Half of the fun is in experimenting. Practice makes perfect. Happy brewing!