Espresso 101: The Essential Tools, Terms, and Techniques You Need to Know to Become a Home Barista

Building a home espresso bar can be intimidating—aside from figuring out which machine and grinder to buy, there’s a bevy of other espresso tools that help pull a great shot. And then there’s the technique—good equipment doesn’t automatically make good coffee. To help you navigate making espresso at home, we put together an espresso 101 guide with helpful things you need to know, like what gear to buy, what some technical-sounding terms mean, answers to typical espresso-related questions, and how to pull a shot step-by-step.

Editor’s Picks: Some Excellent Espresso Gear

A Quick Glossary of Machine Terms

Espresso machines have a lot of unique parts, and knowing what they are and how they work is extremely helpful when learning how to make espresso.

• Boiler: The part inside the espresso machine that heats the water for brewing and steaming. Some machines have separate boilers for each task, which allows you to pull shots and steam milk at the same time.
• PID: Short for “proportional integral derivative,” the PID is a control box that uses an algorithm to maintain precise temperature control. Not every espresso machine has one. Models like the Breville Bambino Plus and Breville Barista Express Impress (a couple favorites from our espresso machine review) do.
• Pump: This builds pressure to send water from the boiler through the coffee.
• Group Head: Where the water exits the machine into the coffee. It houses the dispersion screen (see below) and is where the portafilter locks into.
• Dispersion Screen: A mesh filter screen that turns the powerful water jet in the grouphead into a shower that saturates the coffee evenly. 
• Portafilter: Short for “portable filter,” it’s the handle that holds the filter basket; it twists to lock into the grouphead.
• Filter Basket: A metal basket with holes that acts as the coffee filter. There are a number of different sizes of filters available—single espresso baskets hold seven grams of coffee, double filter baskets hold anywhere from 14 to 20 grams of coffee, and triple espresso baskets hold 22 to 24 grams of coffee. The most common size in the US is an 18-gram double espresso filter basket. Machines also use different diameters of filter baskets. Be sure to double check if your machine uses a 54-millimeter basket or a 58-millimeter basket. 

A Quick Glossary of Espresso Technique Terms

Aside from specific equipment terms, there is also technical jargon that baristas use to describe steps of the shot pulling process. 

• Dialing In: The process of adjusting the fineness of the grinder to reach the ideal espresso shot time. 
• Dose: Portioning the desired amount of coffee into your filter basket—it can be used as a noun (“I used an 18 gram dose”) or a verb (“I dosed 18 grams into the basket”). 
• Distribute: Spreading the coffee evenly throughout the filter basket.
• Tamp: Compressing the coffee into a tight puck using a tamper, so that the pressurized water moves through it evenly. The ideal tamping pressure is around 30 to 40 pounds of force, but the goal is to compact the coffee fully (and you can’t really tamp too hard). 
• Purge: Running some water through the dispersion screen to clean it after the previous espresso shot. This prevents old coffee oils and particles from tainting a fresh shot you’re about to pull. 
• Pull: Taken from the days where baristas literally pulled down a spring-driven lever, pulling a shot these days means inserting the portafilter with a prepared espresso puck into the grouphead, and pressing the button to start the shot. 
• Steam Milk: The process of using the steam wand to aerate and heat milk, creating milk foam for drinks like a cappuccino or a latte. Sometimes this is also referred to as foaming milk, or frothing milk. 

How Do Espresso Machines Work?

Espresso is a brewing process that uses pressurized water to extract a very concentrated version of coffee from extremely fine coffee grounds. The boiler heats the water, and when you press the start button, the pump forces water from the boiler to the grouphead where it’s turned into a shower by the dispersion screen. That shower then saturates the coffee puck and extracts an espresso shot through the filter basket and into your cup.

The brewing process is very fast—around 25 to 30 seconds—and the result is around eight to 10 times stronger than standard drip coffee. Most espresso machines also have a steam wand that can aerate and heat milk, too, opening up the possibility of lattes, cappuccinos, flat whites, and other milk drinks.

Do I Need A Separate Grinder for Espresso?

You don’t necessarily need a separate espresso grinder, but you do need a grinder that’s capable of grinding fine enough for espresso. Most burr grinders are better at making coarse grinds, like those for drip, pourover, and French press preparations. A designated espresso grinder is often better at reaching the fine grind levels needed to pull a good shot. Some espresso grinders—like the Baratza Encore ESP—are also designed to handle coarser drip ranges, too.

If you’re not interested in buying a separate grinder and machine, there machines with a built-in grinder like the Breville Barista Express Impress. While we typically shy away with coffee makers with built-in grinders, the Barista Express Impress also has an automatic dosing system with a built-in assisted tamping lever, streamlining the whole shot pulling process.

Consider Weighing Your Coffee

Espresso is all about precision—a 0.5-gram difference in the amount of coffee you use can dramatically affect the flavor of your shot, as well as how fast the shot pulls. We recommend using a coffee scale that can read 0.1 grams to make sure your dose stays consistent.

And while a double espresso is around two ounces of volume, that volume also depends on how thick the crema is: fresher coffee will have a thicker crema that makes the espresso shot look more voluminous than it actually is. We also recommend weighing your espresso shots for a more accurate coffee to water ratio (usually one part coffee to two parts water). Weight-based ratios give you accuracy and consistency, and let you focus more on adjusting the grind size based on time. If weighing your espresso shots isn’t practical for your workflow, we recommend getting a shot glass with milliliter markings, like the OXO Mini Angled Measuring Cup, since a milliliter of liquid is pretty much equal to a gram.

A Quick Note On Espresso Filter Baskets

The amount of coffee you should dose depends on the size of the basket you’re using, and we recommend swapping out your filter basket for a precision model with a clearly labeled 18-gram capacity. These precision baskets have straight sides and larger holes than standard baskets, and are better calibrated for great tasting espresso. However, machines have different filter basket diameters—Breville machines use a 54-millimeter portafilter, while the Gaggia Classic Pro (another of our favorites) uses a 58-millimeter portafilter. The IMS Precision 18g Espresso Filter Basket is a great pick for 54-millimeter portafilters, but if you have a 58-millimeter portafilter, the VST 18-gram Ridged Espresso Filter Basket is the way to go. 

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