Some flashbacks of Espresso 3

The first two chapters were written about a year ago, and the third part began to be written only after the delay. But the advantage is that there is a deeper understanding of coffee than in the past.

According to the description in the second chapter, the coffee starts to flow out in about 5 seconds. The coffee extracted at this time should be the part with the highest concentration and the first part of the coffee to be extracted. But how does this part taste?

We all like the coffee that has just been extracted. Not all the squeezed amber will be delicious. If we test it with a concentration meter (leave it blank and make up the picture later), the TDS will be as high as 25%. So what does that mean?

The coffee we drink will be extremely strong. But the main manifestation of strong is not bitterness?! It is not that the bitterness of the coffee is not there, but that the acid-dominated flavor absorbed in the early stage far suppresses the bitterness. And we see that the amber color like ink retains the original flavor of the initial extraction, but like a good base liquor, its strong feeling makes it impossible for us to really identify and analyze its specific taste.

At this stage, the part of the coffee we drink is actually absorbed in the first four seconds, while what happens dynamically is a steady stream of hot water that continues to seep into the coffee pressed powder at nine atmospheres. Due to the early extraction of most of the upper end of pressed powder, at this time the water gradually invaded the lower layer of pressed powder. And pressed powder is the lower the structure is looser, the resistance will naturally be less and less. This can also explain why it began to accelerate like the silk of honey falling from the building. Strictly speaking, the efficiency of extraction will become weaker and weaker at this time, because the loose pressed powder structure of coffee shortens the residence time of water per unit time, and in the process of attenuation of flavor absorption, the bitterness of coffee "passes by" in the acceleration of water.

The first 4-10 seconds of the second phase

The thickness of the grinding-most of the initial flavor has appeared in the first 5 seconds but began to decline.

The amount of powder-the amount of powder determines the thickness. The rate of change in color means the amount of powder. Because too little powder will prematurely let the hot water open the road. Thus reducing its plumpness.

The strength of the cake pressing does not matter, because the powder is pressed through the top layer of the powder press, and the powder with the closest texture has been passed by hot water.

Coffee freshness-still has an impact, the fresher, the higher the carbon dioxide content, the longer the baking time, the higher the carbon dioxide content, so the higher the expansion, the greater the resistance. It should be reminded here that too much carbon dioxide in the process of hot water will affect the stability of the extraction. We can see that very fresh coffee produces large bubbles in the process of extraction. This will cause uneven extraction between the left and right sides, even if our pressing powder is correct.

The outflow part is the thickest original pulp in the first 5 seconds. A collection of all flavors, but too strong to be imported.