What size should I grind my coffee? The Brew / Grind Equation

Coffee grinds in portafilter with text what size should I grind my coffee?


Let's get our coffee nerd on!

What size should I grind my coffee?

A simple equation is below to help your coffee brewing experience.

How do I remember what grind do I use for what coffee? And why does it even matter? Is this kind of Hipster/planking/pineapple pen fad so I need to spend my hard earned on some fandango, wizz bang new grinder?

Whoooa! I can see you have some valid points but referencing pineapple pen... really? I digress.

At first it can appear difficult to know what size coffee grinds are needed. When the plethora of ways to brew your coffee are endless, you may just wish to give up and buy pre ground. But if that is the case, we can no longer be friends. We get it though, but to grind your own coffee as you need it, once you try it, there is no going back. Explanation as to why in another blog post.

The equation- as suggested below - makes things simple, and if you follow the principle - your coffee journey from here on will be much sweeter.


The brew grind guide equation the greater or lesser the brew time equals the greater or lesser the grind size

It all starts with the brew time.

Once you know how long you need to brew- then you'll know the size of the grind. Of course there will be some fine adjustments/calibration depending on brew type, but generally speaking, this will get you close.

It all boils down to this - the greater the brew time = the greater the grind size. Alternatively, the smaller the brew time = the smaller the grind size.

Think of an espresso machine coffee- usually the brew time is only about 30 seconds. This coffee has very fine coffee grounds.

On the other end of the scale- something like cold brew- can take 12-24 hours- and the coffee grinds are super coarse.

Why does this all matter? It's all a matter of taste and extraction.

A fine grind will speed up extraction to get flavour out. So considering an espresso is appropriately 30 seconds- it will be correctly extracted.

If the coffee is too coarse for espresso - water will gush through, under extracting potential flavour and taste unbalanced.

A coarse grind will slow down extraction to get the flavour out. So a cold brew brewed for 12 hours is better for extraction of flavour.

Ground too fine - brewed over 12 hours - would result in to much oil extraction and taste as bitter as your mother in law. Just kidding. But yes, it will be bitter and very hard to clean the coffee sludge left behind.

So there you have it.

When all is said and done, if your face contorts and your taste buds die - your not going to want to drink your coffee ever again. Though if you follow the equation above - your specialty coffee experience will be a long and prosperous one. 

If you have any questions about grinding, let us know below-

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