What is the pump of the espresso machine? What's the use?

Professional barista communication, please pay attention to coffee workshop (Weixin Official Accounts cafe_style)

The coffee beans are ready, what's next?

Yes! Pressure!

Many coffee shops seem to have learned the same way: "three knocks"! First press gently, tap three times, then press again, tap three times, then press again, and then put it on the water head.

The tighter the coffee powder, the better?

No wonder someone would get a special filling machine.

This seems to be a deliberate attempt to upset the pump! The tighter you press, the shorter the pump life. Over the years, I have found that the pump damage rate of espresso coffee machines in Taiwan seems to be particularly high, and it will make strange noises after half a year. Is the pump life really that short?

When the pump is broken, some manufacturers will replace the motor together, asking for 1- 20,000 yuan, but do you know that the motor is usually the pump for business models (most small machines are integrated)? Even if it is a pump motor at home, it is also attached to the pump outside the motor! Pumps may break easily, but motors don't! Do you think Italy's industrial technology will be lower than Taiwan? So Italian motors break easily? So it's usually the pump, not the motor! And pumps are more expensive than motors! But no matter how expensive it is, it will not be more expensive than replacing the whole set of motors + pumps.

Why does the pump break easily? It has to do with work stress.

Pump is actually a turbocharger (turbo), theoretically after the pump pressure is fixed. However, powder thickness, uniformity and compaction caused by the intensity of compaction, will change the actual pressure. This is similar to the exhaust system of a turbo car. Turbocharging is the most efficient intake system, but if the exhaust end is not properly coordinated, it will not only consume fuel but also reduce efficiency.

Powder thickness and filling method directly affect the quality of coffee and pump life!

Another cause of pump pressure instability and thus affect the life of the water quality, pump internal structure is sophisticated, poor water quality will cause wear, this is why to install water filters using soft water reasons.

Another reason is "bearing (Pelling)","bearing" is the backbone of power transmission,"bearing" once worn or infiltrated foreign matter will not be smooth,"bearing" not smooth pressure of course. In addition,"bearing" has a certain life, in this certain life, he must also often add lubricating oil to avoid "dry rotation." Otherwise, this life will be shortened. Unfortunately, his location was difficult to repair and replace, so he could only rely on his usual maintenance. But if you don't even know how to open the casing of the machine, how can you talk about maintenance?

So if you find that the pressure is unstable, usually when there is a problem with the "bearing", the "bearing" only costs tens of dollars, but you have to spend a hundred times the money to change the "pump"!

Powder thickness will affect the pump pressure, so it is not the finer the better. The pressure of the pump will also be affected by the force of the filling, so it is not the tighter the better.

The book says that it takes between 18 and 25 seconds to boil a cup of espresso. Do you know how big a difference that 7 seconds is? Not to mention thickness, just tight or loose packing may be 50cc difference, you know?

Pressure tight cook bitter, pressure loose taste incomplete. Too much or too little will make coffee lose its color! If you're selling capuccino and latte, why are they tighter than looser? There has to be some coffee, right? If you're living off espresso, watch out! Just the improvement in the way you compress is enough to increase your espresso combat index several times!

Is it difficult? Not hard!

Just press it!

But this one needs all your strength!

First of all, prepare a weight of pressure, throw away those plastic, aluminum, acrylic, to have weight! Copper or stainless steel will do, remember the size should match the handle filter. Then put the powder into the handle, smooth the powder, and then lean the handle on a place where you can stand on your toes to straighten your hands. Put the pressure into the handle, gently flatten it with the weight of the pressure, and then concentrate your whole body's strength on the wrist. Press the toes down hard. Do not have a second press, the second press will change the first press powder arrangement structure, bitter taste appeared!

Why don't you give it a try?