Make concentrated espresso Italian style, Blue Mountain flavor and Asian mellow coffee beans.

When making Espresso, you only have about 30 seconds to extract, which means that the large coffee particles are really just useless "fillers" that can't be extracted completely or evenly. Espresso coffee powder particles are usually very small so that the water can extract enough flavor substances in a short time. It is important to use EK43 or other similar flat knife mills when making Espresso, because they produce a more uniform particle size distribution of the powder, thus ensuring that most (if not all) of the flavor substances are in consistent contact with water within such a short extraction time.

What does that mean for filter coffee?

When making filtered coffee (such as French press or hand brew), we use a lot of coarse powder, the reason for this is mainly related to the contact time of water powder. Filter coffee extraction time is much longer than Espresso, this is because compared to espresso machine with high pressure pump water can penetrate coffee powder and filter bowl extraction in a short time, filter coffee extraction mainly depends on the gravity of water itself, water through coffee powder speed is much slower. Because of the longer extraction time required, we want to make filter coffee as much as possible to hide the coffee flavor substances in the particles to avoid excessive extraction.

While you are waiting for the flavors inside the larger particles to be extracted, the smaller particles are still being extracted and will not stop. So you need to decide whether waiting is really good for you to extract more from these larger particles, or whether waiting allows the smaller particles to be over-extracted (bitter and dry).