Brewing coffee is the process of dissolving in water some of the substances which are embedded in the coffee beans fibres. There are several factors influencing coffee extraction and what is perceived as strength and taste.
Some cannot be controlled by the person brewing the coffee, other can be controlled by the roaster and things like green bean density depend on the origin of the beans and the farmer.
- Dense beans might need higher extraction time, higher temperature and smaller grind size than a low density bean, to extract the same amount of “stuff”!
- Light roasting need more time and higher temperature to extract coffee than dark roasting (that’s why in the coffee packet dark roasted coffee say)
The person making coffee is in charge and can make a beautiful coffee by playing with grind size, time and water temperature.

It is not only the strength that it’s affected by the brewing variables above but also the taste.
For instance if you find a lighter roast from a dense bean to acidic, you can play around by increase the brew time by grinding finer and using higher water temperature.
If the coffee is too bitter, perhaps the brew time is too long, and water temperature is too high. Try to reduce the grind size and water temperature.
It’s a trial and error process but at the end you’ll find your perfect cup where bitter, sweet and acid are in perfect balance and maybe you can sense different fruits and flowers (not joking)!
Cheers,
Taro
PS: water quality does influence coffee, but this is another chapter!