Bars - A term to denote atmospheric air pressure. 1 atm is 1.013 bar, which is about 14.7 Pounds per square inch. So when we say the Minipresso created 8 bars of pressure, it’s about 8 times atmospheric pressure, which is what you need to create an authentic espresso with a rich crema.
Crema - A creamy golden brown foam / film that forms on the top of freshly made espresso from the emulsified oils from the release of C02 during the brew process. More C02 = more bubbles.
Arabica - A complexly flavored more mild coffee bean endemic to the mountainous regions of Yemen and the southwestern highlands of Ethiopia. Yields about 70% of the total coffee production.
Robusta - A less acidic, more bitter, and more highly caffeinated type of bean. The robusta plant has a greater crop yield than that of Arabica, and contains more caffeine – 2.7% compared to arabica's 1.5%.
Lungo - A long shot of espresso.
Ristretto - A short, smoother, more caffeinated, shot of espresso.
Americano - A shot of espresso cut with hot water to create a quantity similar to drip coffee. Named after American G.I’s in WW2 who would order this while stationed in Europe, because it was more similar to what they were accustomed to drinking back home.
Flat White - Popular in Oceania (New Zealand especially). Espresso served with flat steamed milk.
Latte - Espresso served with frothed milk.
Extraction - Process of pulling flavor from coffee grounds. Underextracted tastes weak and sour, whereas over extracted will taste bitter due to the grinds being exposed to hot water for a longer period.
Roasting - Process of “cooking” green beans to properly prepare them for coffee extraction.
Barista - The person who brews your espresso at a cafe - or in Minipresso’s case; yourself :)