Espresso coffee lovers will agree that the perfect espresso is having the right crema and degree of coffee concentration. Also, achieving the perfect espresso comes down to pressure. There are countless espresso drinks and the popular options include latte, Americano, cappuccino, mocha and macchiato. Read on and let us get to know the essential role of pressure in achieving the ultimate espresso.
How many bars of pressure for espresso?
The ideal bar of pressure for an espresso is nine bars, especially among professional coffee makers. This is considered the universal goal for almost a hundred years already. The bar is the atmospheric pressure measurement and it is also called barometric pressure that is exerted on coffee grounds in an espresso coffee machine. One bar is equivalent to the atmospheric pressure or the weight of air at sea level.
A nine bar espresso maker can produce pressure equivalent to nine times the atmospheric pressure at sea level. The bar of pressure indicates the pressure or force used to push water through the coffee grounds. Flavors, oils and other soluble components are extracted as water is pushed through the coffee grounds. They are released through a spout into a cup.
The bar comes from the Greek word “baros” which means weight. As mentioned above, it is used to measure atmospheric air pressure. One bar is equivalent to 1.47 pounds per square inch or PSI. Thus, for nine bars it is 130 PSI and 15 bars is 217 PSI.
The nine bars of pressure are considered the golden standard starting with the first modern espresso machine designed by Luigi Bezerra, an Italian inventor. Bezzera discovered that water which was heated to around 90 to 95 degrees Centigrade, the ideal brewing temperature, produced the best coffee when pushed through finely-ground coffee at a bar pressure of nine. However, anything above or below the nine-bar pressure pushes water too quickly or slowly. Too little pressure yields under-concentrated and weak espresso while too much pressure results in bitter and over-extracted espresso.
However, while nine bars are the industry standard, some present-day coffee experts note that 15 bars make the best and perfect espresso among domestic and semi-professional coffee machines.
Here are the indications for the specific bar pressures:
Seven bar pressure
Having a seven-bar pressure results in a weak and under-extracted espresso. A pressure that is lower than seven bars prevents water and air from passing through coffee grounds with enough force to extract oils and flavors.
Seven to 15 bar pressure
Seven to 15 bar pressure results in a rich and creamy espresso. This is a typical bar pressure and should also be considered by espresso enthusiasts. This bar pressure gives the coffee machine enough range for an initial kick-off of up to 11 bars and then drops to around 10 bars during brewing.
15 and up bar pressure
Espresso machines rarely use this bar pressure since it results in over-extracted and burnt espresso.
How many bars do typical espresso machines have?
Typical espresso machines use more or less 11 bars of pressure. Baristas note that it is not ideal to buy a coffee machine that has more than 15 bars of pressure since it may just be a waste of money. Most coffee experts recommend investing in a quality espresso machine between nine to 15 bars and that they should be able to learn how to use it effectively.
Do more bars mean better espresso?
No, more bars do not necessarily mean that you will have better espresso quality. There is more to the process than just being able to achieve the right bar pressure. You also need a good quality coffee maker, good coffee beans ground to the appropriate size and decent espresso making skills.
What other factors influence the quality of your espresso besides bar pressure?
These are the other factors that influence the quality of your espresso:
- The amount of coffee in a coffee basket.
- The size of the coffee puck.
- The size of coffee grinds and the finer the grinds the better.
- The quality of the coffee.
- The perfect brewing temperature.
- The type of roast.
Recommended espresso machines with outstanding bar pressure
Here are our recommended espresso machines with outstanding bar pressure:
- DeLonghi Magnifica Super-Automatic Espresso Machine and Coffee Maker
- Breville Barista Express Espresso Machine
- Gaggia Anima Coffee and Espresso Machine
Certain factors are involved in achieving the perfect espresso such as the choice of coffee beans, decent coffee-making skills and the right coffee machine. Nine bars of pressure is considered the golden standard to be able to come up with rich and creamy espresso. However, getting the ideal espresso will still boil down to personal preference and other factors such as temperature, the quality of coffee and the type of roast.
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