The Importance of Grind Size in Extraction
Posted on June 25th 2015 by Maddie
One of most important elements of brewing a Kick Ass® cup is having a coffee grind that correctly corresponds with your brewing time and method.
Grinding exposes all volatile flavours and aromatics locked in the coffee bean. Grind size will greatly affect the coffee you brew.
Essentially, you could just plop a roasted bean in water and expect some extraction. Mind you, it would take a considerable amount of time. Subsequently the extraction rate would increase if you cut the bean in two, doubling the surface area.
Increase the number of particles and extraction will exponentially increase
The rate of soluble solids removed from a coffee particle directly relates to the amount of surface area exposed to water. A higher number of particles will result in more surface area, which can yield a greater extraction.
A higher rate of extraction is not necessarily ideal. Approximately 30% of the matter in roasted coffee particles can be dissolved in water. However, the optimum extraction of the coffee particle’s soluble solid is 18-22%. As not all flavour compounds are pleasant and undesirable flavours dissolve slowest.
Surface area increases as brewing time decreases
When you grind your coffee finely, you are raising your surface area. This has the potential to lead to over extraction. Leading us to the next important factor in brewing coffee, time.
The time that hot water is exposed to the coffee particles must be directly proportional to the exposed surface area, or particle size, of the ground coffee.
Brewing methods vary in brew time. Larger particles release flavour more slowly whereas smaller particles release flavour more quickly.
Using a fine grind for espresso makes sense as the brew time is just around twenty seconds. The finer grind allows all the desired flavours to be extracted in a shorter time.
Whereas for French Press you use a much coarser grind and therefore have an increased brew time.
Importance of uniformity in grind size
Having a uniform grind can make or break your coffee experience. An even consistent grind is of utmost importance when brewing coffee.
Blade grinders lead to inconsistent grinds even when pulsating. They typically produce powdered coffee in combination with large particles. The finer particles lead to a bitter muddy cup, whereas the larger will under extract.
The importance of grind size extends to your grinder. Grinder maintenance is crucial in your continual enjoyment of Kick Ass® coffee.
It is often forgotten that coffee is a food product. Regular cleaning will eliminate the accumulation of stale grinds and rancid flavours from negatively influencing your cup.
Don’t have a grinder? Kicking Horse® Coffee has ground coffee. It is the same fresh quality and deep, delicious taste as our whole bean coffee. But, now it’s already ground and one step closer to the cup. Check out this Blog entry on Nitrogen Flushing to find out how we ensure the upmost quality with our packaging.