Espresso Class

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There’s a whole lot of words associated with espresso.Not just the ones English-speakers have borrowed from espresso’s creators, the Italians, and not just the weird vaguely Italianate ones that big, global coffee chain made up. There’s portafilters and tampers mixed up with doppios and brew ratios, knock boxes for after you’re done pulling a ristretto, and the purge that you give your steam wand before you set about stretching some milk. Yep, there’s a whole lotta words. Here are definitions to the various words and phrases used in the context of making espresso.Affogato: The Italian word for “drowned,” affogato refers to hot espresso poured over a scoop of gelato.Americano: Italy’s version of drip coffee, an Americano is espresso diluted with hot water, typically at about 1:2+ ratio. Learn <a href="https://www.chefsteps.com/guides-tools/how-to-make-an-americano">how to make an Americano</a>.Backflush: The process of running hot water cycles using a blind portafilter to rinse any coffee grounds or residue from the group head.BAR (pressure): A measurement of water pressure (BAR = barometric) exerted on the coffee grounds during the brew process. When an espresso machine uses 9 bars, that means water is being forced through the bed of coffee grounds at nine times the weight of the pressure at sea level. Basic Espresso Theory: The explanation of how the variables of the espresso-making process affects the final product. Learn more about <a href="https://www.chefsteps.com/guides-tools/basic-espresso-theory">Basic Espresso Theory</a>. 
 
Bed: The dose of coffee grounds in your portafilter basket. 
 
Black Eye: For the serious caffeine fiends, this drink combines a double shot of espresso and a cup of either hot or iced brewed filter coffee. Its sibling drink, the Red Eye, contains a single shot of espresso.Blade grinder: Coffee grinder that uses spinning blades to pulverize coffee. Less expensive and smaller than a burr grinder but not as precise or as consistent. Learn more about <a href="https://www.chefsteps.com/guides-tools/grinders">choosing the right grinder for espresso</a>.Breve: Caffè breves are made with espresso and half-and-half. Half-and-half contains 6 to 8 percent more butter fat than whole milk, resulting in a creamier, more velvety texture than other milk-based espresso beverages. Brew ratio: The ratio of the weight of coffee grounds used to produce the coffee compared with the final weight of brewed liquid espresso in the cup.Brew strength: Percentage of total dissolved solids in liquid espresso. Professional tasters typically prefer brew strengths between 7 to 12 percent. For context, espresso is a concentrated brew containing 88 to 93 percent water; drip or filter coffee is 98.2 to 98.8 percent water.Brew time: The amount of time it takes to produce espresso after hot, pressurized water makes contact with ground coffee and the extraction process begins.Brew temperature: The temperature of the water used to extract flavor from ground coffee, which typically falls within the range of [f 197] to [f 205].Burr grinder: Coffee grinder that uses burrs, either conical or flat. Bulkier and pricier than blade grinders, but it’s the preferred tool for grinding up coffee for espresso. Learn more about <a href="https://www.chefsteps.com/guides-tools/grinders">choosing the right grinder for espresso</a>.
 
Caffè corretto: Espresso spiked with aromatic liquor.Cappuccino: Espresso drink with layers of milk and foam on top. More foamy than a latte. Learn <a href="https://www.chefsteps.com/guides-tools/how-to-make-a-cappuccino">how to make a cappuccino</a>.
 
Channeling: It’s the result of when instead of flowing through evenly, the pressurized water finds a pathway of least resistance through the bed of coffee in your portafilter. This throws off the flavor of your extracted espresso.Contact time: Another phrase for “brew time.”
 
Cortado: The Spanish word for “cut,” cortado is essentially espresso “cut” with an equal amount of steamed milk. Also called a Gibraltar, after the style of cup used for service.
 
Crema: The bitter, caramel-colored foam that sits on top liquid espresso. It consists of tiny carbon dioxide bubbles surrounded by water, suspended coffee fragments, and oils.Cup warming tray: By default, on most machines, heat from the boilers rises to the top of the machine, creating a warm surface to store cups.Distribution: Refers to the scattering of coffee grounds in your portafilter basket before tamping; the goal is to break up clumps and have an even distribution before tamping. Distributors: Distribution tools, also known as grooming tools, are designed to level out coffee grounds in your basket to avoid uneven layers that lead to channeling during extraction. These tools often replace tamping or can be used in addition to tamping, but it’s up to you and your personal taste which tool(s) you like to use. Doppio: Doppio means “double” in Italian and refers to a double shot of espresso. An Italian double is, confusingly, close to what is served as a standard shot in the United States.Dose: The amount of ground coffee used to make an espresso.Double boiler: A dual boiler system offers temperature stability, allowing your espresso machine to brew espresso and steam milk at the same time. While technology is constantly advancing, a dual boiler machine allows for back-to-back beverage production. Drip tray: A removable basin and catch-all for water, grounds, and other liquids from beverage preparation.Espresso: Used to refer both to a process of brewing coffee and to the coffee produced using this method. When referring to the coffee, “an espresso” can mean different things, depending on which country you’re in. In the U.S., an espresso is usually 36 to 40 grams of liquid coffee made with 18 to 22 grams of ground coffee; in Italy, an espresso is about 21 grams of liquid coffee made with around 7 grams of ground coffee. Learn <a href="https://www.chefsteps.com/guides-tools/the-espresso-recipe">how to make an espresso</a>. Espresso con panna: Espresso with whipped cream.Extraction: The process of forcing hot water through coffee grounds to “extract” the flavors, fatty acids, lipids, and other elements to create brewed coffee or espresso.Extraction percentage: Amount of dissolvable solids contained within ground coffee present in espresso. Optimal extraction percentage is typically considered to be around 7 to 13 percent while drip/filter coffee is around 18 to 22 percent.
 
Flat white: Espresso drink made with velvety milk, steamed but not frothy, made of tiny, itty-bitty little microbubbles, free-poured into the cup. Learn <a href="https://www.chefsteps.com/guides-tools/how-to-make-a-flat-white">how to make a flat white</a>.Foamed milk: Cold milk that has been aerated with precision. Heating the milk as it aerates will produce smaller bubbles, which is referred to as microfoamed or steamed milk.Gibraltar: Alternative name for cortado.Grading: Green coffee is roasted and “cupped” to identify defects. Coffee scores are based on a scale of up to 100 points. Specialty coffee is coffee that has 20 or less defects, 80 points or higher. Grading can also refer to the sorting process of sorting the beans by size before roasting. Learn more about <a href="https://www.chefsteps.com/guides-tools/beans">sourcing great coffee</a>. 
 
Grind size: Refers to how finely coffee beans are ground. Espresso generally requires a finer grind, which exposes more surface area resulting in a shorter brewing/extraction time than other coffee-brewing processes.Grinder: Tool used to pulverize whole roasted coffee beans. There are two kinds of grinders: blade grinders and burr grinders. Burr grinders are preferred for grinding coffee for espresso and drip/filter methods as they are more precise and produce particles with a more consistent size. Learn more about <a href="https://www.chefsteps.com/guides-tools/grinders">choosing the right grinder for espresso</a>.Grooming: The act of redistributing grounds in the basket, either with your fingers or distribution tools, before tamping to polish the surface of the coffee bed.Group gasket: A thick rubber ring used to create a watertight seal between the brew group and the portafilter. Should be replaced annually.Group head: A dense assembly of precision parts outfitted to receive the portafilter with a watertight seal, allowing pressurized water to pass through the coffee grounds.Hopper: A funnel attached to a burr grinder that stores coffee beans like a silo until it’s time to grind. Hot water tap: A hot water tap that can be used for rinsing or topping off an espresso to make an Americano.
 
Knock box: A receptacle for spent coffee grounds, usually a box equipped with a rubber wrapped bar used to “knock” your portafilter against to release the spent puck after you’re done making espresso.
 
Latte: The heavier, less fluffy sibling of the cappuccino doesn’t rely on layers; instead, it is a velvety, homogenized blend of espresso and textured milk. Learn <a href="https://www.chefsteps.com/guides-tools/how-to-make-a-latte">how to make a latte</a>.Latte art: Elegant designs made with steamed milk that garnish various espresso drinks, including lattes. Learn <a href="https://www.chefsteps.com/guides-tools/latte-art">how to master latte art</a>.Lungo: An espresso with an extended brew time, which results in a larger volume of brewed coffee.
 
Macchiato: ​​The term macchiato translates to “spotted” or “stained” in Italian, which is a pretty on-the-nose description for an espresso drink with just a spot of steamed milk. Learn <a href="https://www.chefsteps.com/guides-tools/how-to-make-a-macchiato">how to make a macchiato</a>.Microfoamed milk: Heated milk that has been aerated. Also referred to as steamed milk. Learn <a href="https://www.chefsteps.com/guides-tools/steaming-milk-for-espresso-drinks">how to steam milk for espresso drinks</a>.Mocha: Also known as a mochaccino, a mocha is a chocolate-flavored latte. Learn <a href="https://www.chefsteps.com/guides-tools/how-to-make-a-mocha">how to make a mocha</a>. Over-extracted: Coffee grounds that have been exposed to water for too long. An over-extracted espresso can taste bitter or even burnt, and it often happens when the grounds are too fine, trapping water inside.Pitcher: Stainless steel container designed for steaming and pouring milk into espresso drinks.
 
Polish: The action of quickly spinning your tamper at the end of a tamp to create a smooth bed of coffee grounds without adding any extra pressure. This not only keeps loose grounds off the bottom of your tamper, it also reduces the amount of grounds around the rim of your portafilter and locks in the surface of the coffee particles so that water can evenly push through when the brew cycle begins. 
 
Portafilter: The piece of equipment that contains the filter basket into which you put ground coffee for espresso. It has one or two spouts on the bottom, out of which liquid coffee flows, and a handle, and it locks into an espresso machine to ensure the pressurized, heated water produced by the group head flows evenly over the ground coffee. There are also bottomless (or naked) portafilters, in which coffee flows directly into the cup (this requires good espresso technique), and there are blind portafilters, which have no holes, which are used to backflush the group head.Pre-infusion: The process of wetting the coffee grounds in your portafilter with little to no pressure before the pump is engaged. This ensures that a portion of the grounds are evenly soaked before high-pressure brewing begins, which helps minimize channeling and results in a deeper, more balanced extraction. 
 
Pressure gauge: Displays how much pressure is being applied to your coffee bed during extraction. 
 
Puck: The compressed cake of wet coffee grounds left in your portafilter basket after the brewing process is complete. The term is also sometimes used to describe the compressed cake of ground coffee before brewing.
 
Puck screen: A stainless steel mesh screen that’s placed on top of your ground coffee before pulling your shot. It serves as an additional layer of protection against channeling by providing an even layer of water delivery to your espresso.
 
Pull (a shot): To brew a shot of espresso. The term comes from the original espresso machines that required users to pull on a lever to start the extraction process.
 
Purge: Removing extant material, whether from a portafilter or from within a steaming wand. Refractometer: Tool used to measure the total dissolved solids (TDS) in a liquid. Used within the context of espresso to determine brew strength or extraction percentage.
 
Ristretto: A ristretto is brewed espresso that relies on a shorter (restricted) extraction time to create a richer, less diluted coffee. While the same amount of ground coffee is used, half as much water (1:1 ratio) and a finer grind are required to get a more concentrated shot.Roasting: Coffee beans (or the seed of the coffee cherry, really) are roasted in order to bring out favorable aromas and flavors, and they’re often characterized by how intensely they’ve been roasted (e.g. light or dark roasts). Learn more about <a href="https://www.chefsteps.com/guides-tools/beans">sourcing great coffee</a>.Scale: An important tool for hitting brew ratios and making espresso consistently.
 
Settling: The act of evenly distributing coffee grounds in your basket, usually by gently and evenly tapping the edge of the portafilter, before tamping. Shot: Term that’s often used to describe a serving of espresso.Steam lever: A lever that opens or closes the valve releasing pressurized steam to the steam wand assembly.Steam wand: A metal pipe and valves attached to the espresso machine’s boiler that can be opened or closed to produce hot, pressurized steam. Used to steam milk.Steamed milk: Milk that’s been heated using the steam wand on an espresso machine; also referred to as microfoamed milk. Learn <a href="https://www.chefsteps.com/guides-tools/steaming-milk-for-espresso-drinks">how to steam milk for espresso drinks</a>.Stretching: Aerating, or incorporating air into, milk with a steam wand as it heats, typically done at the start of the steaming process. Learn <a href="https://www.chefsteps.com/guides-tools/steaming-milk-for-espresso-drinks">how to steam and stretch milk for espresso drinks</a>.Syrup: A liquid solution of sugar and other flavorings, often used in lattes to add sweetness and flavor variations.Tamper: A dual purpose accessory that is used to compress and level the coffee grounds in your portafilter basket before brewing.Tamping mat: Mat that sits on the countertop, which you can use to steady the portafilter while tamping. Offers a level surface and protects both the portafilter and your counter.Texturing: Emulsifying aerated milk by sinking the steaming wand under the milk’s surface. Learn <a href="https://www.chefsteps.com/guides-tools/steaming-milk-for-espresso-drinks">how to steam and texture milk for espresso drinks</a>.

Glossary of Espresso Terms