There are many aspects of coffee brewing that will impact the taste of your drinks. One of these is often overlooked or misunderstood and that is grind size.
That’s why we thought it was important to get back the grind.
Why is grind size so crucial and what size should you choose?
What is grind size?
Grind size refers to the relative coarseness of ground coffee. You can grind coffee coarsely, giving you fairly large pieces like gravel but you can also grind your beans into what amounts to powder.
When you purchase coffee, your choices will often be limited to the two extremes – beans or powder. To refine your brewing, you will need to invest in a coffee grinder. That equipment doesn’t need to cost you the earth and it could make all the difference to your enjoyment of your brews.
How does grind size impact flavour?
Grind size matters because it determines how quickly water flows through coffee and how much of the coffee is dissolved. The finer the grind, the greater the surface area of the coffee and so the slower the water passes through it. You will achieve a much stronger flavour using finely ground coffee.
But you can have too much of a potentially good thing! If your coffee tastes too bitter, it has probably been over-extracted. You should be able to correct the unfortunate taste by using a coarser grind.
On the other hand, if your coffee taste sour, it is almost certainly under-extracted, and you will need a finer grind to address the issue. You may need to indulge in a little trial and error, increasing or decreasing your grind size, until you find the sweet spot.
Is consistency key to success?
Yes! Consistency is vital if you are to get the most out of your brewing experience. This is why a burr grinder is such a fabulous investment.
Grinders may feature either blades or burrs. While blades chop the beans in a similar way to a food processor or blender - haphazardly, burrs work in a different way. Burrs crush the coffee beans between two surfaces and so deliver greater precision. Once you have discovered the perfect setting for your needs, you can repeat your grinds with accuracy every time you wish to brew.
Having said that, there are other factors that will affect the taste of your coffee such as the nature of the roast and the length of time that has passed since the beans were roasted. If you switch coffees, you may need to tweak your grind size to maintain the flavour of your drinks.
If you have always used pre-ground coffee and then start to freshly grind beans yourself, you will notice an instant improvement in the quality of your brews. Coffee beans start to degrade as soon as they have been roasted and degrade more quickly after they have been ground.
Freshly ground is the way to go, regardless of the grind size you need.
What grind size is right for each brewing method?
Different brewing methods certainly require different grind sizes. But remember that you must factor in the roast you are using and the time that has elapsed since roasting when deciding precisely which grind size to go for.
French press brewing
A French press (cafetiere) is a form of immersion brewing. The grounds are steeped in water for a relatively long time, usually around four minutes. It’s best to use a moderately coarse grind as this will minimise the risk of over extraction while still allowing full-bodied flavour to develop.
Pour over coffee
Pour over coffee is brewed by pouring water over coffee that has been placed in a suitable vessel complete with a filter such as a V60 dripper. The finer the grinds, the slower the water passes through them and the greater the extraction of flavour. As extraction will also be influenced by how quickly you pour, you may need to experiment to find what works best. However, a medium grind will usually prove to be the best option.
Espresso
Espresso is brewed quickly and under pressure. Typically, water passes through a portafilter for just 20-30 seconds. For this reason, fine grinds are required to ensure suitable extraction.
Moka Pot
It’s best to use medium-fine grinds when brewing with a moka pot. Grounds should feel gritty but not powdery. A finer grind such as an espresso grind could block the moka pot.
AeroPress
The AeroPress is a versatile brewer that can be used for several brewing methods. The various methods will demand the use of different grind sizes. You may need medium-fine to coarse grinds depending on the brewing method you have chosen. As a guide, consider the grind sizes recommended for each brewing method that is outlined here. If you are unsure about which grind size to choose, start with a medium grind and then make any required adjustments.
Cold brew
Cold brew a brewing method that involves using cold or room temperature water and lengthy steeping times of up to 24 hours and sometimes even more. You will need a coarse grind but exactly how coarse will depend on brewing time and the nature of the roast.
How many different grind sizes are there?
Grind size is measured in microns (micrometres). In theory it is possible to grind coffee to as fine as 1 micron and to as coarse as 1400 microns or more. 1000 microns is equal to 1mm. Coffee grinders vary in the options they give you. Some feature just a few settings to choose from, others offer almost infinite adjustments. It is unlikely that being able to choose from 100 or more grind sizes will transform your coffee brewing experience. You really don’t need to make such tiny adjustments in grind size when home brewing as it is unlikely that you would be able to detect the resulting difference in flavour. A vast array of grinding options wouldn’t be of benefit in most commercial settings either.
Of course, the more complex a grinder is, the broader the functionality it offers and the larger its capacity, the more expensive it will generally be. Explore the available grinders to find the right balance of functionality and cost for your requirements.
Don’t let your choices grind you down
There are many grinders to choose from, each offering a unique combination of features. When presented with so many equipment options and recommendations for brewing methods, you might initially feel a little confused. But don’t let those choices grind you down! You will find a grinder that suits your budget while offering the settings you need. Once you start using your machine, it won’t take long to establish the right grind size for your brewing method and coffee beans. In any case, experimenting with grind size will give you the perfect excuse to drink more coffee!