The existence of a perfect espresso shot is due to some very important components – pressure being among them.
Espresso is an interesting drink – at least that is what I always thought. While it is among the best-known coffee drinks, it remains mysterious because not everyone knows how to make a good shot. I did not know much about making good espresso either until I became a barista. During my time there, I learned an important secret – to use the correct pressure.
I know this seems confusing to a novice, especially when you realize that different machines use different pressure bars to extract the coffee. That is why I write this article basing it on my experiences, and what pressure you should use for the job.
What do you understand by bars of pressure when it comes to espresso?
If you have ever joined a physics class, you probably have heard of bar pressure. However, its meaning may be confusing; with this in mind, it is important to understand what pressure bars are before understanding the best amount of pressure you should use when making espresso.
Bar pressure, also known as atmospheric or barometric pressure simply means the force that the atmosphere exerts, or the weight of air at sea level. “Bars” are metric units that measure the atmospheric force or pressure, and 1 bar is the standard atmospheric pressure at sea level.
What are the different types of bar pressure when it comes to making espresso?
Espresso machines offer three different types of pressure:
- Less than 7 Bars – This pressure is very low, and will result in the espresso becoming under-extracted and weak. This is because it does not allow enough air and water to pass through the coffee grounds under enough force to extract all the coffee’s flavors and oils.
- Between 7 and 15 Bars – Most espresso machines will have this limit, as it is the best for people who want to enjoy great espresso. This range also allows the machine to have a sufficient capacity to handle brewing pressure (8 to 10 bars) as well as the pressure needed for initial, short kicks (10-11 bars).
- 15+ Bars – Very few espresso machines offer a pressure higher than 15 Bars because you will always risk the espresso having a bitter, burnt taste. The high force means the coffee is over-extracted, making it a waste of money.
How many bars of pressure for espresso??
With all this information in mind, the best pressure to use when you are making espresso is 9 bars, although this can vary between 8 to 10 bars. This means that when using 9 bars, you force water through the coffee grounds at a pressure that is nine times that in the atmosphere to extract the coffee quickly.
Many factors will make coffee machines work, but the pressure is what makes espresso machines stand out. The use of the correct pressure is among the keys to making excellent espresso, so it is important to know about it to achieve the perfect shot.
What makes a good espresso machine?
The answer to this depends on what you need your espresso to be since different machines will offer different features.
Does altitude affect the bars you use when making espresso?
Yes, it does. If you live in higher altitudes, you may need more pressure, while lower altitudes may need lower pressure.
How many bars of pressure does Starbucks use?
Surprisingly, its baristas use 18 bars when making espressos, which explains why their coffee tends to have a unique, flavorful taste.
How many bars should a good espresso machine have?
The machine is good enough if it has between 7 and 9 pressure bars, as this produces a balanced result.
How many bars do professional espresso machines have?
Professional espresso machines are pump-driven and use nine bars of pressure to get the best results.
Is it better to use a 15 Bar or 20 Bar machine to make espresso?
Contrary to the belief that using more pressure is better when making espresso, the truth is that using too much pressure results in an under-extraction of the espresso and a weak cup. Therefore, it is better to use a 15-bar machine.