A highly-individual selection by Boughton's Coffee House magazine. This glossary makes no claim to being entirely comprehensive or encyclopaedic!
Acidity: One of the most misunderstood words in coffee-tasting, largely because ‘acid' isn't reckoned to be something digestible. It is better thought of as ‘brightness' of taste.
Americano: A black coffee made up of espresso and hot water. Historically, a derogatory term for GIs who couldn't handle a straight espresso. Today, the subject of complaints from some coffee fans who say that baristas who cannot make a filter coffee properly use an Americano instead.
Arabica: The more desirable of the two main types of coffee. Arabica is high-grown and tasty.
Bar: A pressure rating - you also see it on tyre pressures, where you have the choice of Bar or 'pounds per square inch'. The accepted pressure for an espresso machine is 9 bar, which equates to about 130 psi.
Barista: The Italian term for 'barman', but in England, it's taken to mean someone qualified to work an espresso machine. The poseur elements of the trade use the plural 'baristi', which is technically correct, but suggests they can speak Italian - which they rarely can.
Bean: The middle part of the fruit of the coffee plant, and the part from which a drink can be made.
Body: Description of the overall 'thickness' of a coffee in terms of 'mouthfeel'.
Boiler: Vital part of the coffee machine. In an espresso machine, the boiler provides the heat for the water - but not necessarily the actual water for brewing. In a bulk-brew machine, the water in the boiler is the water which ends up in the cup.
Brew Temperature: Varies according to the drinks.
Brew Time: The guideline for a proper brewed espresso is between 18-25 seconds, or up to 30 for a double. If your single espresso brews outside the 18-25 parameter, this is an alarm to check the settings of your grinder.
Cappuccino: Today, with the introduction of giant takeaway sizes, this is a much-abused drink. It should be no more than five ounces (although seven is fairly reasonable), made with a single shot of espresso, at least one-third steamed milk, and topped with a good layer of carefully-frothed milk. It must not be served too hot! (And strictly speaking, chocolate or cinnamon must not be added to the top without asking the customer).
Cherry: When the coffee bean grows on the plant, the bean is encased in a red fruit known as a cherry. The outer skins and pulp of this cherry are removed at the farm or at a nearby co-operative processing house, leaving only the inner bean.
Crema: This is the dark brown, or dark cream, or golden, or even reddish, layer to be found on the top of a well-pulled shot of espresso. If your espresso has no crema on it, complain.
Cup of Excellence: Not a social, ethical, or'cause' standard as such, although it seems to have panned out that way. C of E coffees are identified by specialist tasters and do not go to conventional processing houses or mills, but are put up for international internet auction, generally concentrating on one country of origin at a time. In general, every coffee auctioned usually fetches two of three times what the farmer might normally have achieved locally, and prices of $5-10 per pound are not uncommon; on many occasions, whole families have been lifted out of debt by the amount paid for their coffee. The world record stands at over $40 per pound.
Cup Warmer: A much-misused part of an espresso machine. It's the tray at the top where the cups sit, ready for use - ideally, espresso should be served into a warm cup, or it will cool too quickly. The mistake most people make is to store cups upside down on the warmer - which means burning the customer's lips.
Demitasse: Delicate cup that takes a three-ounce volume of water, enough for a shot of espresso. They should be quite thick, for heat-retention. Many patterned cups become collectors' items.
Dose: The portion of coffee used in the brew. Generally, a single shot of espresso is seven grammes. In filter coffee, there is a vast amount of argument over the dosages used - 50-60gm for one litre of water is considered reasonable, but it is alleged that many caterers economise by using 40gm in a three-pint brewer, with horrifying results.
Espresso: The beverage produced by forcing water through seven grammes of finely-ground coffee at a pressure of nine Bar. Italy's national drink.
Extraction: A word which is technically correct, but does puzzle the layman. When coffee brews, the flavour is 'extracted' from the coffee grounds.
Fairtrade coffee: A kind of ethically-sourced coffee. To qualify for the Fairtrade Mark, a farm must be certified by the Fairtrade Foundation; a Fairtrade farm must be paid a certain minimum amount for its coffee. There is great argument in the trade over the fact that Fairtrade is not a 'quality' standard, and the Mark simply confirms that the coffee has been bought at that minimum rate. However, it is generally accepted that the standards of Fairtrade coffees have improved, and some are now very good indeed.
Filter basket: In espresso usage, the holder for the seven grammes of coffee.
Filter coffee: A form of brewing in which an amount of medium-ground coffee receives hot water, which makes its way through the grounds relatively slowly. The grounds are generally, but not always, held in a kind of triangular paper cup.
Flavoured coffee: The American market is more used to flavours than the British. In general, flavours are provided by a syrup when the drink is brewed, but there are roasts in which the flavour is added to the coffee at the time of processing. Flavoured instant coffees are now very common.
Foam (or froth): The topping for a cappuccino and some other espresso-based drinks. Frothing milk is an art, although it is often done ham-fistedly. When the steam wand is placed in the milk, hot steam heats the milk. If the arm is ever-so-slightly withdrawn from the top of the milk so that air is mixed with the steam, then bubbles, or froth, are produced. The skill is in getting the bubbles the right size and thickness!
God Shot: A purely American term. It means 'the best espresso you ever made'.
Green bean: - Coffee as it is imported from the origin country. It may not be entirely 'green', but more usually a light khaki.
Grinder: Believe it or not, perhaps the most important part of your equipment. Coffee which has not been ground correctly will not brew correctly, because the water will not pass through it properly, and will not 'extract' the optimum amount of flavour. When an espresso in particular goes wrong, the cause is often found to be that the grinder setting has slipped.
Group Head: The part of an espresso machine which holds the 'portafilter', which is the basket into which the coffee grounds are placed. It is actually a very high-tech part of the machine, because it has to maintain the correct temperature for the brewing water.
Instant or soluble coffee: Derided by the 'real coffee' fraternity, this is the tin-and-spoon coffee that anyone can make. It is obtained in powder or granule form. Some instant coffees have driven the causes of Fairtrade and similar ethical causes.
Knock-out box: A kind of rubbish bin, usually with a bar across the top opening. A barista removes his portafilter after making an espresso, and brings it down with some force on to the bar, thus ejecting the 'puck' of used coffee grounds into the bin. Not the most graceful part of making an espresso, but on a bad day, possibly the most satisfying.
Latte Art: When the milk for a cappuccino is poured from the jug, it is possible, by careful shaking of the jug, to create a picture on the top of the drink. This is latte art. Other forms of decoration, such as shaking chocolate dust through a stencil, or etching designs with a pointer in chocolate syrup, are strictly speaking not 'latte art'.
Latte: An espresso-based drink featuring a large amount of steamed milk, but with only a little froth on the top. The word is Italian for 'milk', and the name of the drink allegedly comes from a barman's insulting term for American servicemen who could not stomach a shot of espresso, and demanded milk with it.
Lever machine: The traditional espresso machine in which the water was drawn under pressure by the pulling of a lever, rather like an old-fashioned beer pump.
Macchiatto: A single espresso with a very tiny quantity of frothed milk. The name refers to the milk being stained or 'marked' with the coffee.
Mocha: A drink rather similar to a latte, but with chocolate syrup or powder added. The result is somewhere between a cappuccino and a hot chocolate.
Moka Pot: It is said that every Italian home has one - a little stove-top machine in which the pressure of steam forces boiling water upwards through a bed of coffee. The result is not entirely unlike espresso.
Mouthfeel: A combination of all the taste sensations of a coffee. Different parts of the tongue react to different aspects of taste; 'mouthfeel' is the overall sensation.
Origin: Much-misunderstood term to signify where a coffee came from. Generally, used to signify a country or region, such as 'Brazilian', 'central American' or 'Indonesian', as if all the coffees from these regions taste the same - which they don't. Some roasters maintain that 'origin' is not a country, but an individual farm.
Over-extracted: Coffee which has brewed too long, and has become bitter or burnt.
Pod: An easier form of espresso brewing which was at first derided by the purists, but is now accepted as a very practical, mess-free, way of making the drink. A pod is very similar to a tea-bag, except that the contents are pressed into a very firm 'cake' of coffee. They were originally called 'ESE', for 'easy-serving espresso'.
Portafilter: On espresso machines, this is the brewing basket which holds seven grammes of coffee, attached to a long handle with which it can be locked into position on the machine while the water is forced through it.
Pre-infusion: It is often thought that if the bed of coffee is slightly dampened before the brew water hits it, the result is better. Some machines feature an automatic pre-infusion.
Puck: The spent 'cake' of espresso after a brew. So called because it looks like the puck used in ice hockey.
Rainforest Alliance: A certifying authority which guarantees that coffee carrying its label has been grown under certain conditions, generally organic, and with certain respect for the environment and the social conditions of the workers.
Recovery time: Critically important in a café situation. Refers to the time you have to wait before the machine is ready to brew its next drink.
Ristretto: A form of espresso in which the same amount of coffee is used, but less water. The result is a much richer, more intense, drinkâ¦ strictly one for the enthusiasts.
Roast: The essential process that prepares a green bean for brewing. Beans are subjected to extremely high temperatures which bring out an inner 'oil' which gives coffee its taste. The bean hardens and darkens during roasting, and can then be ground into the powder used for brewing. 'Artisan' roasting is a skill and an art; 'commercial' roasting is done in immense factories.
Robusta: The less desirable of the two main types of coffee, although it has great value in its way, in providing the power and 'kick' of a blended coffee. Italian espresso always has a strong percentage of robusta.
Semi-automatic: A kind of espresso machine in which the machine automatically sets and maintains some of the parameters, such as water temperature and pressure, but the barista controls the volume of water used.
Shot or 'straight shot': A single espresso.
Stale: In coffee terms, roasted coffee begins to go stale remarkably quickly - some say that it degrades within a couple of days.
Steam knob: Most espresso machines use a rotary control knob to control the steam used for frothing milk. More recently we have come to see lever controls (as on the La Spaziale machines) and latterly an 'ergonomic' rotary control on the Rancilio machines.
Steam wand: The pipe which is placed into the milk jug to steam and froth the milk.
Super automatic: The kind of espresso machine which can do everything at the touch of a button, including steaming the milk. Many are technologically very advanced, though people do worry about the effects of de-skilling on beverage service.
Tall: A Starbucks term for a large latte or cappuccino.
Tamping: - When putting coffee into the brewing basket for espresso, it must be pressed or 'tamped' into a firm pad, or the water will flow unevenly through the coffee, resulting in a poor 'extraction'. A barista tamps his coffee manually.
Tamper: The device used by the barista to press his coffee into the brewing basket. Much debate rages about the construction, size, and even the shape of the base of the ideal tamper. Generally, it is advocated that the barista press downward with a slightly spiral or screwing action, at a pressure of about 30 pounds per square inch.
Thermoblock: Part of the heating system of an espresso machine; rather similar to a car radiator, except that it has the directly opposite effect, in that water gets hotter as it passes through a series of coils.
Thermometer: In the espresso sense, this is a device made to clip on to the side of a milk jug, to measure the temperature at which the milk is being steamed and foamed. Experienced baristas can judge the temperature with their hands.
Under-extracted: Coffee which has not been exposed to sufficient brewing water; the result is weak and thin.
Vente: Highly-derided term, invented by Starbucks, to describe the 20oz takeaway coffee, widely seen as an abomination.
By Ian Boughton