Why Coffee Grind Size Is Important

2 min read

Why Coffee Grind Size Is Important

An often overlooked but critical aspect to consider when brewing your home coffee is the grind (or particle) size.

Each brew method from the home Espresso Machine to the Plunger requires a different grind size to optimally extract the coffee.

There is no one size fits all grind size here unfortunately.

Too big and you can under extract your coffee, too small and you can easily over-extract it. 

This is because the smaller the ground coffee size the easier it is for water to 'strip' the coffee of its flavour.

Home Espresso machines brew at high pressure (up to 9 bar) and fast brewing speeds - around 30 seconds.

This amount of pressure requires a very finely ground coffee to stop the water cascading through the puck.

Whereas a Plunger with its immersion brewing style requires a far coarser grind and longer brewing time - 4 - 6 minutes.

If your grind is too coarse you can end up with a sour tasting coffee, too fine and you will have bitter and harsh coffee.

When you have brewed your morning coffee, have a taste and if you think it is a bit powerful, heavy, aggressive, or generally too intense, just ever so slightly coarsen your grind.

If you think it is sour, salty, bland or just generally underwhelming, grind ever so slightly finer and see if you notice a difference.

These tips can work on any brew method.


What kind of grind do you need?

  • Home Espresso - Very fine grind needed, quite powdery to slow down the 9 bar of pressure.
  • AeroPress - Depending on the coffee and your flavour preferences, a medium to fine grind is recommend.
  • Pour-Overs - There’s possibly hundreds of different types of Pour-Over Brewers available all requiring subtle difference in grind size, broadly speaking medium-fine size is a good starting point.
  • Stove Top Espresso Makers - A medium grind is recommended as they're a fast-ish brewing style that brew under pressure of around 1.5 Bar.
  • Plunger and Cold Brew- Both brew at atmospheric pressure over longer extraction periods, Plungers 4-6 minutes, Cold Brew 12 -24hr. A slow brewing time requires a very coarse grind.

These are all just recommendations and some are very debatable, but as starting point we think the can get you close to brewing perfection.

Happy Brewing!

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