Feeling in over your head with all this espresso making terminology? You're not alone! There’s a whole world of vocabulary to learn, some of which might sound like a completely foreign language if you're just getting started. But fear not -- we've put together a glossary of some of the most common espresso terms, which should help clear things right up.

Automatic Espresso Machines
An automatic espresso machine provides a (mostly) hands-off way to make espresso. With these types of machine, the majority of the process, such as grinding, tamping and even milk frothing, are all done automatically inside the machine.

Bar
Bar is short for barometric pressure, which measures how many atmospheres’ of water pressure is exerted on your espresso during the brewing process. Most machines apply around 9 bars of pressure during extraction, but others may be higher or lower based on the brand. 

Bean Hopper
The bean hopper is a container on top of your espresso machine (or grinder) that stores whole beans. Once the grinder is activated, the hopper will funnel the beans directly into the grinder's burrs.

Brew
To brew is the process of creating liquid coffee from roasted beans. Whether you're using ground coffee beans to make espresso, pour over, drip coffee, or any other type of coffee, all of these processes are considered brewing.

Brew Temperature
Different brewing methods typically require slightly different water temperatures while brewing. Generally speaking, the ideal water temperature for making espresso (brew temperature) is between 190 and 205 degrees Fahrenheit.

Brew Time
Brew time measures the amount of time water flows through (or makes contact with) your ground coffee. This will vary based on the brew method, but for espresso, most will aim for a brew time of around 25 to 30 seconds.

Brew Ratio
Typically measured in grams, this is the amount of coffee grounds compared to the final amount of liquid espresso in your cup. For espresso, the most common brew ratio is around 1:2. This means if you started with 18 grams of ground coffee, you would aim for 36 grams of liquid espresso. This ratio will be different for various other brewing methods, such as pour over, French Press, etc.

Burrs
These are the metal rings inside an espresso grinder that are responsible for grinding your beans. When compared to blade grinders, burr grinders are highly preferred for espresso use, as the resulting grinds will be much more evenly and consistently ground.

Channeling
Likely one of the most common terms tossed around when learning espresso, channeling is when high-pressured streams of water flow quickly through gaps or "channels" in your prepared coffee grounds. Channeling is typically caused by improper puck prep, and can cause over/under extraction and undesirable flavors in your cup.

Coffee
Coffee is a catch-all term for any beverage made from roasted beans from the coffee tree. The term “coffee” applies to espresso, drip, French press, pour-over, and even instant. The way the coffee is brewed is what differentiates the styles of coffee. So in other words, all espresso is considered coffee, but not all coffee is considered espresso.

Coffee Bed
This is the mass of prepared grounds that have been tamped into your portafilter.

Crema
This is arguably one of the most telltale signs of a fresh roasted, quality, and properly prepared coffee. Crema is the rich, caramel-colored foam found on the surface of the coffee directly after brewing. Crema is formed from the oils and CO2 found inside the beans, both of which naturally escape the beans as they age. This is why seeing crema on the surface of your shot of espresso is a good indication that the beans used were fresh.

Distribution
The process of spreading your coffee grounds evenly throughout the entire filter basket, without any pocket or clumps. Uniform distribution of your grounds is crucial to pulling a well balanced shot of espresso, and can be achieve with tools such as a WDT, and a distribution tool.

Dose
This refers to the amount of coffee you're using for your brew method. For example, if you're using 18 grams of coffee in your portafilter, then 18 grams is your dose.

Dosing Cup
A specialty cup that is specifically designed to measure your dose, load your grinder, catch your grinds, and load your portafilter.

Drip Tray
The drip tray is the lower portion of the espresso machine that catches excess runoff and/or drips during the brewing process, keeping your countertop clean. Most drip trays will also be responsible for catching any excess water purged from the group head after brewing. In the rare moments when our espresso machine is not in use, we like to keep the drip tray covered with a tamping mat that doubles as a safe place to pack the portafilter.

Espresso
Espresso (not express-o) is made by forcing high-pressure water through finely ground coffee beans. This technique results in a highly concentrated brew that’s rich, creamy, and full of complex flavors. Espresso is the base coffee ingredient used to create popular drinks such as lattes, cappuccinos and cortados, and even one of our favorite desserts -- affogatos.

Extraction
In espresso-making, extraction is the process of forcing hot water through coffee grounds, pulling out all the "good stuff" from the grounds. The extraction process will yield your final product, espresso.

Filter Basket
The filter basket is the metal "basket shaped" insert that holds your coffee grounds inside of your portafilter. The bottom of the filter basket is lined with tiny holes, allowing espresso to pass through, leaving the grounds behind. Filter baskets are generally available in single, double, or triple shot sizes.

Foam
A milk or cream based liquid that is typically used as a base for most espresso drinks. Foam is created by introducing hot air to the milk or cream with an espresso machine's steam wand.

Grinder
A grinder is used to break up coffee beans into smaller parts for different brewing processes. A burr grinder, which is typically preferred for espresso, uses two discs to grind whole coffee beans into fine, uniformly ground coffee. Some machines come with built-in grinders, while others require standalone grinders.

Grounds
After being run through a grinder, crushed coffee beans are called grounds and are ready to be brewed into coffee.

Knock Box
After brewing, your portafilter will be packed full of hot spent grounds. The easiest – and most aesthetically pleasing – way to empty your portafilter into a knock box. A knock box is a countertop container that's dedicated to holding used coffee grounds/pucks. Most knock boxes come with a rubber cross bar inside, which is made for "knocking" your portafilter on to dislodge the spent grounds, dropping them into the bin.

Manual Espresso Machines
Want to have full control over every aspect of the espresso making process? A manual espresso machine – like the minimalist Flair 58, for example – might be the right fit for you. A manual espresso machine will require every stop of the process to be operated without electronic automation -- grinding, tamping, and even applying pressure during extraction, will all be done by hand.

Over-Extraction
Remember when we defined extraction as drawing out the good stuff from the grounds? Well, too much of a good thing, is also a thing. If too much water flows through your coffee grounds or the coffee has been exposed to hot water for too long, you'll begin extracting undesirable flavors, leaving your coffee over-extracted.

Portafilter
You can’t make espresso without a portafilter. This is the removable ladle-like part of the machine (with a handle) that holds your filter basket and coffee grounds. Your portafilter is what makes the connection between the coffee and the machine. We’re especially fond of bottomless portafilters, which have the bottom and spouts removed, allowing you to see your shot extracting in real time.

Pre-Infusion
Right before the espresso machine kicks things into high gear and begins extraction, it applies a small amount of low pressure water to saturate the grounds. This process is called pre-infusion, and helps to primes the coffee for more consistent extractions.

Puck
Once your coffee grounds are tamped down in your portafilter into a tight, dense disc that looks a bit like a hockey puck...you now have...a puck.

Puck Screen
The job of a puck screen is to act as a mediator between the group head and the coffee, interrupting and diverting the high-pressure streams of water for a much more controlled, balanced flow through your grounds. Puck screens are a key component to helping fight stubborn channeling and spurting.

RDT
Ross Droplet Technique, or RDT, is a technique of adding a tiny bit of moisture to your whole coffee beans just before grinding. The preferred method is to use a pump or two of water from a fine mist spray bottle, then shake the beans in a dosing cup to evenly distribute the moisture. Caution should be taken when using this technique, as the added moisture on the beans may cause damage to some grinders, and/or may cause them to hold onto residue and gunk up prematurely.

Shots
Simply put, a shot is one unit of espresso. A double shot would be two units of standard strength espresso and so on.

Spouts
These are the miniature funnels on the bottom of a portafilter that help direct your espresso into your cup or shot glass. If you're using a Crema Bottomless Portafilter, you can actually get yourself a set of removable Bottomless Spouts, giving you the best of both worlds.

Spurting
If you’re having trouble with your puck prep technique, little jets of hot coffee may spurt or spray out of the bottom of your portafilter's filter basket. This is an indication that you likely have channeling occurring inside your grounds.

Tamping
Unlike most other brew methods, espresso grounds aren't ready to brew straight out of the grinder. Tamping is the act of compressing the ground coffee in your portafilter before brewing. You’ll do this with a tool called a tamper, which will help create a smooth, level and dense bed of coffee to prepare for extraction.

Under-Extraction
A well-balanced cup extracts just enough of coffee’s delicious flavors without going overboard. Under-extraction is stopping a shot prematurely and not fully extracting all of the flavors the coffee has to offer.

WDT Tool
WDT, or Weiss Distribution Technique, is a method of puck preparation that aims to evenly distribute coffee grounds in your portafilter. A WDT tool uses thin wires to rake through the grounds to break up clumps, providing a more even and balanced extraction.

Yield
The yield is the amount of liquid espresso that you’ve extracted from your grounds, which is typically measure in grams.