This is perhaps one of the most common questions I receive behind the bar - and it's a fair one.
The espresso shot has long held the perception that the consumer of the dark liquid magic is a coffee aficionado who means business - they are on the go and care not for small talk. They need their caffeine fix now, and they need it fast.
The drip coffee serves to be consumed more slowly, to withstand lengthy conversations - be it the enjoyable kind with an old friend or the painful kind over a teleconference call.
So, which packs the most punch?
One cup of drip coffee contains more caffeine than an espresso shot.
One 2 oz. double espresso shot contains about 80mg of caffeine.
One 12 oz. brewed coffee contains about 120mg of caffeine.
Espresso contains more caffeine concentration per ounce. As you may have noticed in the numbers above, there is more caffeine concentrated in one ounce of espresso vs. a drip coffee. Now we re-visit caffeine concentration per oz:
One single shot of espresso has about 40mg per oz.
One brewed cup has only about 10mg per oz.
But #IRL (In Real Life - yes, that that hashtag is a thing), we aren't walking around with 6 shots of espresso in our hands. We are consuming an espresso shot rather quickly and we are slowly consuming brewed coffee - which leads me to my next point.
How fast are you drinking your coffee? This plays a role. Caffeine can be more rapidly assimilated when consumed in concentrated dosages. And therefore impacts your central nervous system more than say, being consumed in less concentrated dosages. Therefore can have a greater impact on your central nervous system than drip coffee - for a more immediate response anyway.
Why does espresso have a higher concentration of caffeine?
There are many variables at play here. But here are the main culprits:
The finer the grind, the greater the contact water has with the coffee grounds' surface area. This makes saturation across the grounds much easier as well. This influences how quickly caffeine is saturated. Also, espresso is prepared using pressurized water and more coffee grounds than drip. This all results in more caffeine being removed from each little coffee ground.
SCAA Espresso Definition:
Espresso is a 25-35ml (.85-1.2 ounce) beverage prepared from 7-9 grams (14-18 grams for a double) of coffee through which clean water of 195 °-205 °F (92 °-95°C) has been forced at 9-10 atmospheres of pressure, and where the grind of the coffee is such that the brew time is 20-30 seconds.
SCAA Three stages of Brewing Process:
Wetting: Pre-infusion, initial contact of grounds, opening pores of coffee, C02 so process can begin, Extraction: diffusion, Hydrolysis: larger water
insolubles are broken down
General Rule of Optimum Extraction:
27-35% roasted coffee can be dissolved in water, best flavors from dissolving 18-22% mass of coffee. Percentage of solids extracted from coffee is called the soluble yield, extraction, or extraction yield.