When you go to your favorite coffee bar, you expect, above all, a really good espresso!
We asked Santana, our experienced barista, what makes a good espresso. What requirements and ingredients should be met and how can we recognize the quality of the little black coffee we love so much?
There are basically three criteria for quality: the differentiated aromas, the taste and the texture. In a good espresso, these are in a balanced relationship with each other.
The taste is related to the sweetness and bitterness. The coffee bean contains various oils, carbohydrates in the form of fructose, which caramelizes when roasted. Pressure and temperature create complex chemical reactions and delicious aromas that arise during the roasting process at different temperatures.
Here are the 10 Barista Secrets
1. Quality of the green coffee
As with wine or olive oil, the origin and variety of the green coffee are crucial for its taste. Not all coffee is the same. The coffee plant is very sensitive and cannot tolerate frost or temperatures above 30°C. Coffee grows in the higher regions in the partial shade of trees and with regular moisture. Robusta, one of the two types of coffee, is less sensitive and has twice the caffeine content of the more noble Arabica bean, but also has less fine and fruity flavor components.
Small-scale farming structures often produce higher quality results through a lot of manual work and better selection than industrial cultivation methods in large coffee plantations. The best green coffees come from Costa Rica, Colombia, Panama or Ethiopia, the origin of coffee.
2. Roasting
Here again we make a comparison with wine. Depending on the type and intended use, there are different ways to achieve the optimum taste.
Basically, over 1,100 different flavors are created during slow roasting in a drum roaster. During the different temperature levels during roasting, the proteins react with acids, the so-called Maillard reaction. These thermal reactions influence the five flavor components that we humans can taste: sweet, salty, sour, bitter and umami - which can best be described as savory.
The degree of roasting and the duration of the roasting process are therefore decisive for the taste. Espresso from southern Italy and Portugal is roasted darker, and therefore has more intense roasted aromas and a subtle bitterness. Lighter roasts come from northern Italy, America and France, which are therefore somewhat more fruity.
3. The water
An espresso consists of almost 99% water. Ideally, water should be medium hard, as water that is too hard (calcareous) not only damages the machine, but also eliminates important coffee acids that give the coffee its flavor. The water should not have too few minerals either, as certain coffee aromas need minerals such as calcium to develop the full coffee flavor. Professionals and enthusiasts therefore filter the fresh water. For home use, there are smaller table filters for little money. In this case, any water filter is better than none! You can find out the local water hardness from the waterworks.
- Good coffee water contains limited minerals and has a high oxygen content
- Stale and distilled water takes away the aroma of the coffee
- Water filters compensate for deficiencies
4. Grinding
Santana is honest here! According to his standards, a good grinder for the home costs at least €300 - €400. There are two types of grinders that differ in the grinding mechanism. Conical grinders are durable, but are an exception today. Today, flat or conical disc grinders predominate. The larger the disc diameter and the lower the required speed of the grinder, the more gently and cooler the coffee is ground. If the grinding disc diameter is smaller than 55 mm, this is usually compensated for by higher speeds. This heats up the ground coffee a lot and is essentially re-roasted, which makes the coffee bitter.
Freshness is also key when it comes to ground coffee! Ground coffee should always be ground on demand and consumed immediately. For our barista Santana, immediately means less than 1 minute. The reason is simple. When grinding, the cell walls of the beans break down and some of the volatile essential coffee oils escape immediately.
Santana's tip for grinding :
Coffee is hygroscopic - that is, it attracts water. The grinder setting should be checked regularly. When the humidity increases, the grinder should be set a little coarser, because when moisture is absorbed, the water flows more slowly through the portafilter during brewing. The target run-through time of 24-28 seconds can be used as a benchmark for the grinder setting. Our professional Santana recognizes this during extraction and makes a test espresso first thing in the morning. See, smell, taste...
5. The tampon
A topic in itself - the flow time is significantly influenced by the compression. There should be around 20 kg of pressure on the loose ground coffee in the portafilter. The so-called "cake" should be tightly and evenly compressed in the portafilter. This allows the water to be evenly distributed throughout the portafilter and to optimally extract all the desired aromas in the various extraction phases.
Too little compression results in under-extraction, the coffee becomes watery and less aromatic
If you condense the coffee too much, it will be over-extracted and the coffee will taste slightly burnt and noticeably bitter and sour.
Santana's tip: practice a lot and use a special tamper with a built-in spring that triggers at 20 kg. It's important to get a feel for the right pressure.
6. The amount of coffee
Espresso is a highly concentrated and complex aroma in a small amount of liquid. When extracting, we want to get the maximum aroma, but avoid bitter substances and too many acids.
The more coffee you use, the more you can extract. As a rule of thumb, use 7-9 g for a single espresso and around 18-21 g for a double espresso. This also depends on the degree of roasting; the darker the coffee, the more likely it is to use 7/18 g. For lighter varieties, you can use a gram more.
7. The brewing temperature
This is where the most technical changes have been made to the machines in recent years. Thanks to digital temperature control (PID), at least the brewing temperature during the extraction process can be controlled very well.
Basically, we need a brewing temperature of around 88-96 °C to achieve optimal extraction. The brewing temperature should be maintained throughout the entire water path. The brewing group and portafilter should also be preheated accordingly.
A single origin coffee, i.e. a single-origin coffee from a single plantation that only consists of Arabica beans, needs a lower brewing temperature; a strong espresso with a higher Robusta content needs slightly higher brewing temperatures. At temperatures above 96 °C, the coffee burns in the portafilter and there is a risk of over-extraction, which leads to a bitter result.
8. The extraction time
The extraction takes place in different phases. It only starts dripping out of the outlet after about three to four seconds. The fatty coffee oils are the first to dissolve. The extract comes out of the outlet dark and rather viscous. After about 15 seconds the complex acids appear, the extract is lighter and slightly foamy, while the aromas dissolve evenly. At the end of the extraction, hardly any of the desired aromas dissolve, the outflow becomes increasingly thinner and ultimately determines the amount in the cup. If you exceed the extraction time window of about 24-28 seconds, the noticeable bitter substances increasingly develop.
9. The cups
The cups should be pre-warmed. Our barista Santana places the cups with the bottom on the machine - this allows them to warm through without the rim getting too hot. The ideal cup temperature is around 63 degrees. Strong espresso cups are not only stable, they also retain heat better. For hygiene reasons, the cups are covered with a clean cotton cloth.
10. The coffee machine
There is no such thing as "the one" perfect machine! A barista who knows what he is doing can make a good coffee out of any decent portafilter espresso machine. For espresso lovers, there are good single-circuit machines starting at around €900. If you also want to froth milk, you can find a good dual-circuit machine starting at €1,100. Here there are two separate heating circuits for water and steam, which we need to froth milk.
Barista tip :
Santana is also very consistent here: The 2-sieve is better for extraction than the 1-sieve. This is because the water travels the same distance everywhere during extraction with a two-sieve. With a one-sieve, the water path is longer at the edge than in the middle. A longer path means uneven extraction. Over-extraction occurs at the edge and under-extraction in the middle.
Conclusion
Fresh, high-quality coffee, a good grinder, a portafilter machine and freshly filtered water - the rest is experience and craftsmanship that we are happy to share. In our barista workshop, Santana shows how to make a good espresso and what is important. In addition to some theory, there is a lot of practice and the end result is a great taste experience.
