Professional coffee roasting | comparison of the effect of double-layer pot and single-layer pot

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Karma saw a manuscript, because the individual does not have the relevant background, can only believe that what it describes is true, I drew it, the purpose is to find out the differences, to explore whether the operation surface can compensate for the fundamental differences in the structural plane.

This is a semi-hot fan with excellent performance and double baking barrel body.

When its fire row heats the air passing through the combustion chamber to 260C, it will heat the outer layer of the baking bucket to 350C at the same time. However, due to the air buffer between the inner pot and the outer pot, the temperature of the inner pot is only 180o200 degrees. When ABR (air to bean ratio) is appropriate, that is, when the amount of exhaust air and the amount of baked beans reaches the appropriate ratio, the hot air baking effect of this machine is quite excellent. Everyone praised the beans it baked. The flavor has high cleanliness and sweetness.

Suppose there is another machine with the same baking capacity, which also emphasizes its hot air baking ability, but its baking bucket has only a single layer and is only a slightly thicker stainless steel pot body, assuming that the steaming capacity is as strong and directly applies the same conditions. I'll show it as follows.

The firepower and air volume of single-layer pot is compared with that of double-layer pot.

In the same exhaust air intake, fire source conditions, the same height from the cylinder, the single-layer pot body temperature will be equal to the above-mentioned double-layer pot outside the temperature of 350 degrees, the intake temperature is also 260 degrees, assuming that the mixing capacity is also the same, the same amount of beans, under the same air volume, the baking rhythm of this single-layer pot may be much faster, and the variation of flavor will be very different, even causing scorching taste. Obviously, the pot body is different, and the possibility of failure of the whole pot is quite high when baking under the same conditions, and the reason for the failure is that the temperature of the pot body is too high in order to maintain the high air temperature under high air volume, so that in the baking process, in addition to the hot air effect of high air temperature, the higher contact heat of the pot body temperature leads to the rapid rise of bean temperature.

What if the wind volume remains the same, but the firepower is turned down? The temperature of the pot body is not so high, but the air temperature will also drop. Even if the baking rhythm and time can be adjusted to be close to that of the double-pot machine, the flavor will be different due to the difference in the ratio of hot air and contact heat, as shown below.

The firepower of the single-layer pot is reduced, but the air volume is still similar to the strong wind of the double-layer pot.

The above explanation is only talking about the idea that "every machine has its own characteristics, and when the characteristics are very different, it is sometimes desperate to ask for the same flavor." to make matters worse, it is difficult to correct the concept. For example, blindly pursue the baking method of strong wind and big fire.

A roaster takes a long time, because it is an investment in money, time, and space, so you must choose carefully before purchasing, and the first priority you choose is your own requirements and needs. If you can't even determine your own flavor, it seems just right to spend money and take time to make mistakes.

In addition, don't get me wrong that I prefer double-layer pot-body machines. to be honest, I prefer machines with great ability to change. For example, the single-layer pot body with a good wind road and fire can be baked in a strong wind and fire, or you can make good use of the high-temperature pot body to produce a flavor similar to that of an iron pan, with a wide range of changes, which is just suitable for a funny game like mine. But if you want to do business and pursue stability, the consideration will be different.

The firepower and air volume of single-layer pot can be adjusted to give full play to its specialty.

What's the point of this article? Just because I am a frog in a well, I have never seen the analysis of a double pot. When I see a manuscript as a treasure, of course I have to write down my notes immediately.