Tomo’s little school of coffee

3. August 2022.

The coffee here is worse than in the last place… we won’t go there, they overheat the milk… here they serve me brown water instead of coffee… there is too much foam here….

How many times have you heard such comments? Or worse, said them yourself?

Don’t worry, you’re not alone. I too made these comments countless times before I decided to explore the vast world of coffee. I remember how scary it was at the very beginning of my research because everyone had an opinion or a trick up their sleeve. Wondering why that’s scary? Maybe because each person had a completely different comment, which was actually inevitable because coffee depends so much on subjective taste. Now, after a few years, that doesn’t surprise me anymore, considering how big the world of coffee is.

In order to save you a couple of years of confusing learning about coffee, I have prepared a few tips and tricks that significantly influence the flavours of your favourite black drink, but are often overlooked.
So, let’s go…


Although you may have never wondered how water affects the quality and taste of coffee, believe me, it has a huge impact. Our drink is actually about 90% water (and as much as 98% in filter coffee). The remaining percentage of the drink are other substances, such as oil and caffeine.
It is very important that the barista takes care of the water quality. Most espresso machines are connected to depurators which soften the water. In addition, water filters (BWT, BRITA) that remove chlorine and heavy metals such as lead and copper are being used more often, and technologies have even developed to release magnesium into the water in ionic form for additional mineralization. Additionally, the temperature of the water is very important. For example, for espresso it is recommended to use water between 88 and 96 degrees Celsius (depending on variety of the coffee and roasting level).


The machine should be washed once a week…. The machine should be washed after brewing 1 kg of coffee, every day, and a maximum of 2 times with Percaffe…We were told that this damages the machine…

I could write a whole book about the cleanliness of the machine itself, but in the end, it can be reduced to one rule – wash the machine every day! Regardless of the number of brewed coffees. Just like we wash the dishes at home every day, right? I think you will agree with me that it is not very pleasant to eat from dirty dishes.
Likewise, when brewing coffee, it is important to rinse the group (the so-called splash/flush) for a few seconds to wash away the coffee residue and to bring fresh water into the group, and after shaking out the coffee cake, wipe and clean the portafilter as well.

The cleanliness of the machine and portafilter (handles) is extremely important. At the end of the day, if you follow hygiene during your shifts, the cleaning takes about 15 minutes, which is really not that much, and it will give your coffee a better taste. Additionally, at the beginning of the day, the barista should drain the water from the machine that was left in the machine during the night, so that new, fresh water comes to the boiler, which is done by running water on groups and running water from the spout (or both at the same time), and check if the machine is well washed.


This is something we can notice immediately upon entering the coffee shop in most cases. The view is directed towards the coffee machine, and we notice several layers of condensed milk on the steam wand. Totally unattractive, right.
Personally, I don’t order coffee in places like this, at least not in combination with milk.
Every barista (or person who makes coffee) has to take 4 steps:
· release steam (due to condensed water)
· steam the milk
· release the steam again (to expel the remaining milk from the steam wand)
· wipe the steam wand with a damp cloth so that the milk does not curdle

The unhygienic steam wand is not good for us for obvious reasons, nor is it good for the machine, because it gets clogged due to layers of old milk and with low pressure we will not be able to steam the milk properly.
Now that we have mastered the cleaning routine, we can start steaming the milk. We can say that steaming takes place in two phases:
· The first stage is forcing air into cold milk, which will create foam. The rise of the foam must be monitored, with a steam wand just below the surface so that no additional foam is created.
· In the second stage, it is necessary to rotate the pitcher a little in order to create a vortex in the milk. We call this part milk polishing, where we break the large bubbles into billions of tiny bubbles, which we call micro foam.

The goal is to bring the milk to about 55-60 degrees Celsius. We can roughly estimate the temperature if we are able to hold the body of the pitcher firmly for a few seconds. If we can’t, the milk is probably a little too hot. Another, easier way, would be to use a thermometer.
Here, I would just like to emphasize that you should try to avoid reheating milk whenever possible, because with each reheating, we break out the fat from the milk and make it watery.


This blog post ig getting a little long, which is no wonder because I could write and talk about coffee for days, so we will finish with espresso-based drinks, of which there are 6 basic ones. All other versions are derivatives that we usually get as an order, and we can make them very easily if we know the basic 6.

The espresso recipe depends on the barista and is measured in grams. It should contain twice as many grams as the weight used to make it (e.g., if we use 8g, the espresso should weigh around 16g), and the preparation takes between 20 and 30 seconds (it depends on the granulation, water temperature, pressure, degree of roasting, etc.). If we prepare espresso in about 25 seconds, the amount will be somewhere around half a cup (it is a common misconception that espresso must be half of cup)

Probably the drink that is most often prepared incorrectly. In Italian, macchiato means stain, and from that we can conclude what this drink should be – espresso and a small spoonful of warm milk cream. That’s it, although for us in Croatia, macchiato means 1001 different things.

A drink closest to our coffee with milk. It is made on the basis of double espresso, steamed creamy milk is added, and the volume of the drink is about 150ml.

There are almost as many variations of this drink as there are for the macchiato. According to most recipes, this drink is made in the ratio of 1:1:1 (coffee:milk:foam), although this has changed recently. Cappuccino is prepared from one shot of espresso and warmed creamy milk is added to the total volume of about 170ml. When you order coffee with milk and get a full cup of coffee (most often with one of the latte art motifs), consider it a cappuccino.

No, these are not two different drinks. The drinks are the same, the only difference being that caffe latte is prepared in a ceramic cup and latte macchiato in a glass (first milk, then espresso) to create the effect of coffee in layers.

Oh, that famous americano. We prepare it by making espresso and adding hot water. The amount of the drink is about 120ml (of course it also depends on the taste of the consumer). This should be a diluted espresso flavour similar to filter coffee. We can pour water first, and espresso on top, to make it aesthetically more appealing, but the taste will still be the same.

I would like to conclude by noting that none of these basic drinks are prepared with cold milk, because cold milk neutralizes natural sugars found in coffee. Warm milk, heated to 55-60 degrees Celsius, contains proteins and milk sugars that additionally “sweeten” our coffee and dilute the bitterness.
So, if you see that the drink you got is creamy, feel free to try it without sweeteners. You might be shocked 😊

Until another time, with another topic (related to coffee of course)!

Tomislav Košutić
Coffee Expert