Espresso

The amount of caffeine in a cup depends on three key factors: the coffee bean, the amount of ground coffee used, and the serving size.

Coffee bean: Robusta beans are true caffeine powerhouses, containing between 2% and 4.5% caffeine. Arabica beans, by contrast, contain only 1.1% to 1.7% caffeine. In addition, caffeine levels can vary considerably between different Arabica and Robusta varieties.

Amount of ground coffee: The more coffee grounds you use in your portafilter, the more caffeine is extracted into your cup. This factor has a greater impact than the roast level, as caffeine remains largely unchanged during roasting.

Serving size: Caffeine is water-soluble. A Café Crème, for example, contains more caffeine than an espresso when prepared with the same amount of coffee grounds, because the larger volume of water extracts more caffeine from the coffee.

If you'd like to know the exact caffeine content of different coffee drinks, take a look at the table in our article about caffeine, where we compare the caffeine content of various espresso-based beverages.

Since a 2015 assessment by the European Food Safety Authority (EFSA), the figure of up to 400 milligrams of caffeine per day has been widely cited as a safe intake level for healthy adults. If you prepare your espresso the way we like it, using 18 grams of ground coffee and extracting 42 grams of espresso, you'll end up with roughly 70 to 100 milligrams of caffeine per cup. Based on those numbers, up to four cups per day should be well within the recommended limit.

The volume of an espresso depends largely on the barista. If you're brewing espresso at home, the final yield is determined by your recipe and machine settings.

As a reference, we brew our light-roasted espresso coffees using a 1:2.5 brew ratio. With 18 grams of ground coffee, this results in around 42 millilitres of espresso in the cup.

Dark-roasted coffees often perform better with a 1:2 ratio. Using the same 18 grams of coffee, you would aim for a yield of approximately 36 millilitres.

The word “espresso” comes from the Italian term espressivo, referring to a coffee that is prepared specifically for an individual customer. The term emerged at a time when this style of coffee had to be ordered directly at the bar of a café and brewed on demand.

Contrary to a widespread misconception, the word is not derived from “express,” even though the association with a quickly prepared coffee seems plausible. Nor does espresso originate from the Latin word expressum (“to press out” or “to squeeze out”).

So, strictly speaking, an espresso is never an “expresso coffee.” If anything, it is closer to being an “exclusive coffee”: a drink prepared especially for you.

You type it in a hurry and hit Enter before noticing the mistake. After all, you'd never spell espresso with a double “s” at the beginning, would you? Or would you?

Don't worry. Around 2,000 people search Google for “esspresso” every year. Another amusing, but still incorrect, variation is “essepresso”. Perhaps the roughly 140 searchers were trying a little too hard to embrace the Italian accent.

The more attentive coffee drinkers know there has to be a double “s” somewhere. But where exactly does it go? Over the past 12 months, around 320 people opted for the wrong version and searched for “esspreso”.

The word espresso demands quite a bit from our fingers. Its letters are spread across the entire width of a QWERTY keyboard. No wonder that around 170 people seem to run out of steam before reaching the final letter, turning espresso into “espressp”.

Even more thoroughly brewed are the coffee lovers searching for “esppreso” (75 searches). But we'll forgive them. After all, there are still plenty of people who associate espresso with “express” and end up attaching nothing more than an “o” to the end.