Powder quantity control (supplement) and pressing powder

Mentioned scraper, it allows you to control the amount of powder, but the disadvantage is that it will waste the amount of powder.

Mentioned scraper, it allows you to control the amount of powder, but the disadvantage is that it will waste the amount of powder.

In fact, it also has a limitation, if a filter bowl can hold 18g powder, the scraper can only control the amount of powder by scraping off the powder. So the upper limit of the powder bowl of 18g is only 18g.

Of course, some baristas know that by tapping a filter bowl filled with coffee powder, you can make the coffee powder sink, thus increasing the amount of coffee powder. But what many people may not know is that about 10 years ago, most baristas had never heard of the concept of powder addition (updosing).

In fact, Australia's only world champion, Paul Basset, won the first place by adding powder in 2003, and the then Tim Wendelboe (world champion in 2004) questioned it.

The final result is that the coffee is judged by the taste of the coffee, and it is not said that the powder can only be filled with 14g. From the point of view of my cognition, in fact, it was at that time that most of the weight began.

Before I move on to the following topic, let me help you sort it out again.

1. If the grinder is set, the parameters of the coffee machine are constant, the same coffee beans are used that day, and conceptually, the only thing that can change the coffee extraction is the amount of powder.

two。 The flow rate of coffee can be changed when the amount of powder is more than 0.5g, and the taste will be basically the same when the amount of powder is less than 0.3g.

3. We need a way to control the amount of powder. Because now the vast majority of grinders on the market are unable to control the amount of powder within this general reference.

4. Scottie invented the scraper in 2006, which controls the amount of powder by different radians.

5. The defects of scraping have shown that it is impossible to add powder and is easy to be wasted.

6. The knock or handle of Paul Basset makes it possible for us to have a large amount of powder. In view of point 4, different radians relatively control the amount of powder, and point 6, can the amount of powder be controlled by addition rather than subtraction? There's a way out.

Suppose:

If in the middle of receiving the powder, pier 1, and then pick up the powder, then the powder piled up a hill, and then pier 1. We can abbreviate (11)

If you receive half of the powder, do not pier, and then finish the powder, at that time the powder is still piled up a hill, and then a pier. We can abbreviate (01)

So obviously, 11 will be a little bit more pink than 01.

How much is it, depending on the size of the powder bowl? But in general, it will be adjusted at about 0.2-0.3g.

Then, if in the middle of receiving the powder, pier 1, and then finish the powder, at that time the powder is still piled up a hill, and then pier 2. We can call it (12) for short.

Because when there is a hill, the pier is heavier than half the powder, then 12 will be about 0.2g more than 11.

In short, the number of piers can be fine-tuned.

Because the pier filter bowl makes the powder on the filter bowl sink, which means you can hold more powder. The more you build, the less you will wipe off the excess powder.

The proportion increases from 00,01,10,11,21,22, so that you can control the amount of powder accordingly.

For example, you find that at 01, your flow rate extracts the espresso of 25ml in 22 seconds, and you find that the texture is thin.

Then maybe you can try to increase the amount of powder a little to increase its texture and consistency before adjusting the grinder. Then the easiest way is to change the original 01 to 11, then your flow rate will be slightly slower, because the amount of powder has increased slightly.

This system may seem a little complicated just now, but when you really understand and master it, you basically don't even need an electronic scale in addition to taking notes.

Moreover, it allows you to quickly adjust the flow rate you need.

Of course, before doing this, there are a few essentials to master:

1. The strength of each pier should be the same.

two。 Wipe the powder flat every time, because if there is any pressure to go down, more powder will be filled virtually.

3. The action of powdering should be the same every time.

If you wipe off the excess powder with an arc, it naturally means that you wipe off more powder than in a straight line.

The above three points require a lot of practice.

But keep in mind that if 0.5g can significantly change the flow rate, then any of the above three points can easily make your powder quantity more than 0.5g error. In the world competitive competition, 0.3g is the target value of barista training. But on the contrary, if you master this technology, you will find it very beneficial. Because you can fine-tune your powder almost at will. And be consistent.

In fact, in Australia in the past decade, the technique may be slightly different, but all the contestants have used this method, including Scottie himself.

Scottie won the WBC competition in 2010 and no longer uses scratches. It depends on the "pier" approach, and the advantage is that when one barista takes over from another barista, it is easier to tell the next barista 11 than to tell him the actual weight of powder.

Perhaps the strength of the two baristas is different, but only a little adjustment is needed to ensure the consistency of the powder quantity. This topic is much more boring. But if you are a barista, you have to participate in the competition, no matter what method is used, the consistency of powder quantity is something you must master.

This is not only the guarantee of the successful completion of the competition, but also the basic requirement of your quality control consistency in the coffee shop. But I believe that in the future, with the development of science and technology, the improvement of the grinder, and the more profound understanding of coffee, there will be a more scientific coffee extraction system.

But the essence remains the same, that is, how do you steadily give your customers, your judges a good cup of coffee. At this point, you and I all need to keep pace with the times.

Let's talk about pressing powder.

Objective: to make the loose powder tight by a certain pressure, so as to make the pressurized hot water permeate evenly.

Here, several problems are involved, which is actually a vector problem. The direction of powder pressing, as well as the strength of powder pressing.

The direction of pressing powder: (it may be a little more complicated than we thought) this is obvious, vertically downward. If the pressure is inclined, the high-temperature and high-pressure hot water coming out of the boiling head will seek the infiltration of the layer with the least resistance, resulting in uneven extraction. At the same time, it is easy to have the channel effect that we often talk about. I need to explain this. I don't need much.

But with regard to the direction of powder pressing, it will indirectly involve another problem, that is, the problem of powder distribution (grooming). The biggest reason why we want to cloth powder, of course, is the control of the amount of powder, that is, if the amount of powder is distributed flat and the excess amount of powder is scraped off, then the same action each time can ensure the same amount of powder.

In fact, there is another reason, that is, to distribute the powder evenly. Because a traditional theory is that the water in the head is evenly permeated, so the powder should be flat and the powder should be flat, so that the extraction is uniform.

(some people think that the water coming out of the cooking head will eventually be concentrated at one point, so the powder hammer needs to be curved, but there is no essential difference between the two after test and blind test.)

Some people don't think so. If you pay attention to Stephen Morrissey in 2008, he actually has no cloth powder after receiving the powder through the grinder. When the powder is piled into a tapered hill, press the powder directly.

This has more or less found some answers from coffeegeek's release of VST basket in April.

First of all, although our effluent is average and the pressure can be evenly distributed, a very important hardware limitation is the basket.

First of all, take a look at a picture from coffeegeek, we can see that the vast majority of basket holes vary in size.

Secondly, we have the opportunity to look at the basket of the coffee handle. In fact, the distribution of holes is not uniform, but the center is denser and the edges are sparse.

In other words, the chances of being infiltrated by water in the middle are far from the edge.

This, more or less, can explain the uneven distribution of powder in Stephen during the competition. Because when a cone is piled up, most of the powder is concentrated in the center of the basket, which compensates for the uneven extraction.

It is also because of this discovery that VST makes its own basket holes very uniform in size and distribution. Thus applied for a patent.

(http://www.coffeegeek.com/opinions/markprince/04-29-2011)

Of course, with this basket, it is impossible to press pressed powder directly without cloth powder.

This is also when the new basket experimented with coffeegeek, mark prince had to change the way Stephen used to do. The power of powder pressing (which may be simpler than we thought) the most basic question is how powerful it is, how much kg.

I have heard of 25kg before, and I have also heard that Italians regard coffee as their life and touch it gently. In explaining this problem, one of the most basic problems needs to be corrected.

Strength should be described by Newton. (the reason will be explained later)

If we explain it in terms of Newton, then let's convert it first.

15kg is a more commonly used description, so when converted into Newtonian units, it is 15kg*9.8N/KG, that is, about 150N.

Next, let's take a look at the power of nine atmospheric jets of water on Coffee pressed powder. Nine atmospheric pressure means that in a unit square meter, there is a force equivalent to nine atmospheric pressure, which is 900KN/ M ^ 2.

The area of our average 58mm diameter pressed powder is (58 58mm 2 to 1000) ^ 2 to 3.14, that is, about 0.00264 square meters.

Then the pressure generated is 900, 000, 000, 0.00264, or 2380N.

The 150N produced by the powder hammer is obviously negligible compared with the flow of 2380N at nine atmospheric pressure.

At the same time, there is another important factor to consider. When La Marzocco designed the Swift automatic filling device around 2000, they experimented with forces ranging from 2 pounds to 30 pounds (that is, about 15kg). Found that no matter how much power, the power to the bottom of pressed powder is almost powerless.

This is like a car collision experiment, where the extrusion and deformation of the car body itself is the result of absorbing energy.

Therefore, the conclusion drawn from these two points is very simple: the strength of the powder does not have much to do with it, as long as the powder is pressed tightly.

At the same time, it is more important to keep the powder pressing force consistent every time.

Postscript:

The North American system is slightly different and is more likely to adjust the grinder to fix the amount of powder. But the pier's approach is still widely adopted.

It will be discussed in detail later. What is interesting is that when I was going to write this diary, my friends asked me why I wanted to compete and why I shared the core knowledge. What I just want to say is that I really don't want to see a lot of young players adjust the machine and the coffee extract can't be dripped out on the stage. such a competition is meaningless. And the control of powder quantity, according to my observation over the past few years, is the weakness of many Chinese coffee players. More importantly, I have witnessed the exchange and sharing of coffee circles in Australia since 2007. In the critical period of the game, regardless of the door, without reservation. If, during that period, technology still played a more important role, then Australia has done an excellent job in this respect, and the core of it is this sharing. You know, around 2009, Matt Perger was an 18-year-old hothead. With our mutual help, 2011 has become the third runner-up in the world. This is all brought about by a small team and a big environment. When we complain that others are ignorant and naive, why not share what we know to those in need? After all, every contestant doesn't want to risk becoming cannon fodder, and not everyone who runs a coffee shop tries to provide coffee quality without knowing what to do. From my cognitive view, and values, the significance of competition lies in communication and sharing. After talking about the concept of extraction, Michael Philips looked at the young barista in the coffee shop with a smile. "I know, you know, he knows, everyone can make good coffee and make money, won't everyone be happy?"