My espresso machine is by far my favorite kitchen appliance (even more so than my air fryer, which is next in line). Once you adjust to drinking shots of espresso, a concentrated, pressurized version of coffee, just using a drip coffee maker simply isn’t enough. Though many people rely on the magic brewing process that ensues inside espresso machines, few take the time to appreciate the process of how an espresso machine works.
Let’s examine the brewing process to discover what makes espresso machines so special (and different from a regular coffee maker). Doug Parkison, Category Director at De’Longhi Group, shared his expertise to explain what happens inside your espresso maker.
How an espresso machine works
Before we discuss how an espresso maker works, it’s helpful to understand what makes traditional drip coffee different from a shot of espresso. The golden foam on top of a freshly brewed espresso shot, known as the crema, comprises tiny bubbles of carbon dioxide gas that dissolve into water during the pressurized brewing process.
In simple terms, Parkinson describes how an espresso machine works:
“Espresso machines work by forcing hot water through finely ground coffee beans that have been tightly packed (tamped) into a portafilter. This process, which occurs at high pressure, extracts the coffee’s rich flavors and oils, creating a concentrated, flavorful shot of espresso topped with a layer of crema. Frothing milk or milk alternatives with a steam wand allows you to craft a variety of additional espresso-based drinks, such as lattes and cappuccinos.”
Steps in the brewing process
For the average espresso lover, the following steps provide a simplified process of what takes place inside your espresso maker. Unless you’re an engineer, these steps provide enough of an understanding of what makes espresso brewed with an espresso machine much different than strong coffee brewed with a drip coffee maker.
- First, your espresso machine will heat the water to near boiling point.
- Next, the inner pump will force pressurize water through the coffee you’ve packed into the portafilter (filter basket). The pump is responsible for creating the necessary pressure to make the entire process work.
- High pressure and hot water work together to extract flavor from the coffee, resulting in a shot of espresso with a crema on top.
Types of espresso machines
Although all espresso machines work the same way, there are a few differences depending on the type you have. The pressurized brewing process remains the same, but different types of makers require a different level of work on the user’s part. Some people may prefer more control over the brewing process (such as in a manual espresso machine), whereas others may prefer the ease and convenience of an automatic espresso machine.
- Automatic espresso machines: Automates the espresso brewing process, including grinding, tamping, and brewing
- Semi-automatic espresso machines: Involves a bit more manual work, such as manual tamping and grinding
- Manual espresso machines: Full control over the brewing process
Brewing espresso and steaming milk
Another fun part of using an espresso machine is the ability to customize any espresso beverage and experiment with your inner barista skills. Whether you want to brew plain shots of espresso or wish to use the stand wand to create steamed milk for a cappuccino or latte, each component of your espresso machine has its purpose to help you craft cafe-style beverages.
Brewing espresso
According to Parkinson, “Authentic espresso, brewed at 9 bars of pressure from 18 to 21 grams of finely ground coffee (resembling table salt), should yield 36 to 42 grams of liquid, adhering to a 1:2 brew ratio. The extraction process should produce a rich, reddish-brown stream with a thick, golden-brown crema. The taste should be balanced: a pleasant bitterness, sweetness, and acidity, with notes reflecting the bean’s origin. Improper extraction leads to sourness (under-extraction) or harsh bitterness (over-extraction). Proper tamping, using about 30 pounds of pressure to create a level coffee puck, is essential to prevent channeling and ensure even extraction.”
Steam wand
The steam wand attached to your espresso maker is another key component of its operation, especially if you’re interested in making drinks like cappuccinos, lattes, or macchiatos. Parkinson shares his best tips for using a steam wand:
“For steamed milk, start with cold milk in a stainless steel pitcher. Purge the steam wand, then position it just below the milk’s surface, creating a gentle whirlpool. Slowly lower the pitcher as the milk foams and heats, stopping at 140 to 150 degrees Fahrenheit. The type of drink determines the milk texture and volume: A latte, typically a 10- to 12-ounce beverage, requires a thin, velvety microfoam and a larger volume of steamed milk, creating a creamy, smooth texture throughout.”
