The only thing that distinguishes espresso from other types of coffee is pressure. While a variety of coffee makers may provide a short, concentrated brew, the high pressure produces the trademark richness and crema we enjoy.
Various values may be proposed regarding how much pressure is required. So, How Many Bars Of Pressure For Espresso do we need? The short answer is 9 bars, but there is so much more.
Continue to read and find out!
- How Many Bars Of Pressure For Espresso?
- What Do Bars Of Pressure Actually Mean?
- How Does Pressure Affect Espresso Quality?
- 9-Bar vs. 15-Bar Pressure Espresso Machines
- Making Espresso
- Does Altitude Affect Bars In Espresso?
- Does Espresso Really Have More Caffeine Than Regular Coffee?
- What Are The Best Beans For Espresso?
How Many Bars Of Pressure For Espresso?
Every barista instruction or book will tell you that 9 bars are the ideal pressure for creating an espresso.
So that has been the perfect pressure for espresso machines since the equipment was developed. It was determined that the extraction has the right flavor at this amount of pressure but can fluctuate between 8 and 10 bars.
When water is pumped through a coffee puck at roughly 9 bars, it becomes saturated with the carbon dioxide present in the grounds. This produces tiny, delicate bubbles.
In other words, crema comprises oils, proteins, and CO2. It only happens when the correct amount of pressure is applied.
However, suppose the pressure pump is less than 8 bars. In that case, the coffee will flow excessively slowly, resulting in an over-extracted espresso.
If the pressure pump is set to more than 10 bars, the coffee will decrease too rapidly and become unsteady. This coffee will be under-extracted. Of course, the flow will have an impact on the taste.
What Do Bars Of Pressure Actually Mean?
What exactly do we refer to when we talk about bar pressure?
The pressure or force exerted by the atmosphere is measured by barometric or atmospheric pressure. It is simply the weight of air at sea level.
One bar is about equivalent to atmospheric pressure at sea level and is a metric measurement.
When producing espresso, 9-bars of pressure, or nine times the weight of the pressure at sea level, should be exerted through the coffee grinds.
Understanding this can be challenging, especially when discussing how much pressure is required when producing a shot of espresso. Let’s use vehicle tires as an example to put this into context.
An automobile typically requires roughly 32 PSI (pounds per square inch). You’d think this is a lot of strain, wouldn’t you? After all, we’re talking about a vehicle tire.
9-bar pressure is required for an excellent shot of espresso. This is the equivalent of 130 PSI, which is more than four times the pressure used in a typical vehicle tire.
How Does Pressure Affect Espresso Quality?
So, let’s move on to something I’m sure you’re more interested in: how does pressure affect the quality of your espresso?
When you apply too much pressure to prepare your espresso, there will be less time of contact between the grounds of the coffee and the water. The water will flow through too quickly, making the espresso weaker.
As pressured water travels through the coffee grinds, tastes, oils, and other soluble components are extracted.
If you don’t apply enough pressure, the water will remain in touch with the ground coffee for too long, resulting in a more robust, bitter-tasting espresso.
Pressure is only one component of a good espresso shot. However, my long experience has shown me that the flow rate through the coffee puck is significantly more crucial than selecting an arbitrary pressure profile.
To create a consistent flow, you should preferably try to reduce your pressure as the shot continues owing to puck erosion.
Many of the better-automated machines already handle this, so it’s one less thing you don’t have to worry about.
So, to sum up. When you vary your pressure, the evenness of your espresso extraction and the volume of extraction will change.
When your extractions become uneven, you’ll detect a sour mix of under-extraction and strong astringency. If your extraction is just low, you will obtain a lot of sours. The higher the extraction, the sweeter it will be.
9-Bar vs. 15-Bar Pressure Espresso Machines
If 9 bars of pressure is the sweet spot, why are there machines that give 15 bars of pressure?
No, it’s not a brilliant marketing trick to say “more is better.”
Higher pressure indicates that your espresso machine has more power beneath the hood. In most circumstances, the entire 15-bars of pressure will never be used.
To return to the automobile analogy. Consider a Ferrari. It’s quick, very fast, but you’ll never put your foot on the floor when driving about town, but the extra power is available if needed.
The same is true of a 15-bar espresso machine; they have the power, but it is not utilized.
Because many espresso machines lose pressure between the group head and the pump, they begin with 15-bars of pressure (more than is necessary), but the actual pump pressure that touches your coffee will be about 9-bars.
Taking this into account, if your machine only produced 9-bars of pressure, you would not have enough pressure traveling through your portafilter to provide a fantastic-tasting espresso.
It is preferable to have more pressure that is not being used than to have a machine that is under pressure.
A valve to guarantee that the pressure for brewing is constantly around 9-bars is a standard feature found in many of the top espresso machines – the excess pressure is expelled from the device.
Before we go into bars of pressure, let’s go through the fundamentals of preparing espresso. The entire process may be broken down into five essential parts.
- Finely grind your coffee beans.
- Fill a portafilter halfway with coffee grounds.
- Tamp down the coffee grinds using a tamper.
- The coffee machine uses high pressure to force hot water through the coffee grinds.
- Espresso drips through the portafilter’s bottom, ready to be utilized.
The Perfect Bar
The bar measurement (also known as barometric pressure) is essentially the number of atmospheres of stress imposed on coffee grounds. A bar of 9, for example, implies that the pressure of the water being forced through the coffee grinds is nine times that of Earth’s average atmospheric pressure of 1 bar.
Now knowing what bar pressure is, you’ve probably worked out that step 4 of creating an espresso shot is when your coffee machine’s bar pressure comes into play.
Did you realize, though, that various brands of coffee machines require differing levels of pressure to extract the ideal dose of coffee? The optimal level of the bar running through your coffee grounds should be between 7 and 11 bars, while specific espresso machines may reach higher bars. Devices that can get 9 bars of pressure will be able to make a rich and concentrated espresso shot. Furthermore, you don’t need to use regular coffee in an espresso machine because of its taste and flavor for your favorite beverage.
The Crema Of The Crop
Crema, the delightful golden creamy material that lies on top of the most incredible espresso shots, requires a minimum of 7 bars of pressure while passing through the coffee grinds for espresso perfectionists. Many claims that while 7 bars is the very bare minimum necessary to extract a quality espresso shot, you’ll need considerably more to get the most out of your coffee beans.
Electric Steam Coffee Machine
This coffee machine works similarly to a conventional Moka Pot but utilizes electricity rather than a cooktop.
Steam is driven through the coffee grinds using an internal boiler, and the extracted coffee is poured into a cup or pot. This style of the coffee machine, while potentially less expensive, is incapable of producing a proper espresso shot.
The issue is that electric steam coffee machines can only create 1.5 bar of pressure while also boiling the water at an excessively high temperature. This produces a weak shot with an acidic taste. Certainly not the best outcome for a coffee purist.
Pump Coffee Machine
Pump coffee machines are significantly superior at providing the necessary bars of pressure to extract a professional-quality espresso shot.
One of the primary reasons pump coffee machines outperform electric steam machines is the presence of separate systems for producing bars of pressure and regulating water temperature.
The same system manages these as an electric steam coffee maker, which means that extra heat is necessary to boost the bars of pressure. This might destroy the quality of your coffee beans. Pump coffee machines do not have this issue since they can provide the ideal amount of pressure and the perfect degree of water heater for a balanced extraction.
It’s also worth noting that for pump coffee machines with bar ratings of 15 or 19, this is not the amount of pressure applied directly to the coffee grinds. This is the amount of force generated by the pump, which must travel through many other sections of the machine before reaching the coffee grinds. When your espresso shot is withdrawn, you will still be within the ideal range. It will simply take less time than a machine with lower pressure bars.
Does Altitude Affect Bars In Espresso?
For those who understand how pressure works, this is a reasonable question.
The temperature and air pressure fluctuate as one ascends in height. This is useful for brewing processes since the boiling point of water varies with altitude.
Furthermore, decreased ambient pressure causes more significant CO2 degassing from the extracted liquid.
When we talk about espresso machine extraction, it happens under 9 bars and is entirely independent of ambient pressure.
However, at higher elevations, it will off-gas more quickly, resulting in a loss of sweetness and crema owing to quicker degassing.
Does Espresso Really Have More Caffeine Than Regular Coffee?
Espresso has more caffeine per ounce than regular coffee, but it is often eaten in smaller portions. An 8oz cup of regular drip coffee may have up to 120mg of caffeine, but a 1oz espresso shot may contain up to 50mg (5).
What Are The Best Beans For Espresso?
The best espresso beans are dark roasted, yet any bean may be used to create espresso. Espresso coffee beans are not a specific variety; they are simply given a roast that makes them appropriate for producing espresso.
To condense and simplify, the perfect pressure for your espresso should be approximately 9-bars.
When looking for a new espresso machine, please don’t get too caught up in how much pressure it has.
Many of the most excellent machines can produce more than 9-bars, and some 15-bar devices include an automated release valve to guarantee that about 9-bar touches your coffee, and the surplus is disseminated.
Thanks for reading “How Many Bars Of Pressure For Espresso”! We hope that with this article, you will now know more and master the art of making espresso!