How many bars of pressure for the perfect coffee and espresso?

Raising the BAR

When it comes to understanding coffee, BARs of pressure are often laid to the wayside in favor of discussing coffee bean varieties, roast levels, and the various ratios required to make different styles of coffee. And yet, knowing about BARs of pressure is essential for anyone that owns a coffee machine – or is planning to buy one – since it directly correlates with how effectively your coffee machine can make espresso shots and extract flavor. So, if you want to learn all about the BAR necessities of coffee, look no further!

Making Espresso

Before bringing BARs of pressure into the picture, let’s quickly go over the basics of how espresso is made. The entire process can be divided roughly into 5 simple steps.

1. Grind up your coffee beans finely
2. Place the coffee grounds into a portafilter
3. Use a tamper to pack down the coffee grounds 
4. The coffee machine pumps hot water through the coffee grounds at high pressure
5. Espresso drips out the bottom of the portafilter, ready to be used

The Perfect BAR

The BAR measurement (known as barometric pressure) is essentially the number of atmospheres of pressure exerted upon coffee grounds. A BAR of 9, for example, indicates that the pressure of the water being pushed through the coffee grounds is 9 times that of Earth’s standard atmospheric pressure of 1 BAR. 

Now that you know what BAR pressure is, you’ve likely figured out that step 4 of making an espresso shot is where the BAR pressure of your coffee machine plays a big part. However, did you know that different types of coffee machines actually require varying amounts of pressure to extract a perfect shot of coffee?  The ideal level of BAR passing through your coffee grounds should be around 7-11 BARs of pressure, though some espresso machines will be able to hit higher BAR. Machines capable of hitting 9 BARs of pressure will have the ability to produce a rich and concentrated espresso shot.

The Crema of the Crop

For those espresso perfectionists who pay close attention to things like crema - which is the delicious golden creamy substance that sits on the top of the best espresso shots - a bare minimum of 7 BARs of pressure when passing through the coffee grounds is required. However, many argue that though 7 BARs is the absolute bare minimum requirement to extract a decent espresso shot, to really get the best out of your coffee beans, you’ll need much more. 

Electric Steam Coffee Machine

This type of coffee machine functions quite similarly to a standard Moka Pot but uses electricity instead of relying on a stovetop. By using an internal boiler, steam is forced through the coffee grounds and the extracted coffee pours into a cup or pot. This type of coffee maker, though perhaps a more economical option, is not capable of extracting a quality espresso shot. The problem here is that electric steam coffee machines can only produce 1.5 BAR of pressure, while also boiling the water too hot. This results in a weak shot that is acidic in flavor. Hardly the ideal result for a coffee purist. 

Pump Coffee Machine

Pump coffee machines are far better at producing the right BARs of pressure to extract the type of espresso shot that would be of a professional level. One of the main reasons that pump coffee machines are superior to electric steam ones (aside from being able to produce much higher BARs of pressure) is the separate systems present to create BARs of pressure and regulate the water temperature. In an electric steam coffee machine, these are governed by the same system, which means additional heat is required to increase the BARs of pressure, which could ruin the flavor of your coffee beans. Pump coffee machines do not suffer from this problem as not only can they produce the perfect amount of pressure, but they can also create the right level of water heat for a balanced extraction. 

It’s also important to note that for pump coffee machines with ratings of 15 or 19 BARs, this is not the amount of pressure that is exerted directly into the coffee grinds. Rather, this is the amount of pressure produced by the pump, which needs to pass through various other parts of the machine before reaching the coffee grounds. This means that you’ll still be within the optimal range when your espresso shot is extracted. It will just likely take less time than a machine with lower BARs of pressure. 

The Right Machine for the Job

We’ve determined that a pump coffee machine is a must for a great espresso shot, but how much pressure should these machines be able to produce for optimal results? 15 BARs of pressure from the pump is a must. This is because pump machines have more complex parts and require more pressure to travel through the machine before reaching the coffee grounds. 

The EspressoWorks Espresso and Cappuccino Machine can produce up to 19 BARs of pressure and the EspressoWorks All-In-One Coffee Maker can produce up to 15 BARs of pressure. Both these machines come with a top-of-the-range Thermoblock system and are ready to use in about 45 seconds. 

These two pump coffee machines land within the optimum pressure range, so you know you’re going to have an amazing crema-loaded shot of espresso with each and every extraction. Bundled with amazing sets of accessories, you’ll have everything you need to extract espresso like a professional barista! Best of all, you know that with the high pressure both can produce, you’ll always be able to reach the optimal range for espresso extraction and will never have a weak or watery shot!