Real Espresso Myths that Need Busting
If you follow me on Twitter, or on Google+, you’ll know I was a bit miffed a while back at some video “coffee myths” put out recently by an online cooking school regarding espresso. The videos produced by ChefSteps are quite good overall, but the myth “busting” videos were ones I had some real problems with. A lot of what they covered either aren’t myths (in other words, they are true issues with espresso), or they covered the myths wrong. This got me thinking that maybe I need to publish a real Myths About Espresso guide. So here we go.
Myth #1 You Can Make Espresso Without an Espresso Machine
No, you cannot. Espresso, by it’s nature since about 1946 or 1947, is a concentrated beverage made by inducing very high pressure (much higher than just steam on its own can do) to push water through a finely compacted bed of ground coffee. That pressure, under the modern term for the beverage espresso, is about 9BAR, 135psi, or 930Kpa.
I know the inventor of the Aeropress claims his product produces espresso, but it does not. There is a nearly 3,000 comments thread on CoffeeGeek, dating back to 2005, where this specific subject was debated ad nauseum (go give it a read!) and included a lot of discussion with the Aeropress inventor directly.
To make espresso, you need an espresso machine. There are manual, no electric ones (the Presso, the ROK, the Handpresso, the Mypressi come to mind); there are versions with no pump (La Pavoni Europicolla, or the Elektra Micro Casa a Leva); and there are many, many with pumps. The $69 Salton types that have a knob on top for the steam boiler? Not an espresso machine (regardless of what they say on the box).
Myth #2 Medium Roast has More Caffeine than Dark Roast
All coffee beans of a specific type have more or less the same amount of caffeine, purely by weighing the caffeine only, no matter how light or dark roasted. Here’s the deal on caffeine in coffee, and how it interacts with heat, water, and extraction.
Caffeine is very resistant to burning off or leaving the bean as it roasts. In fact, because it is one of the more resistant things in the bean to changing / burning off / leaving / dissipating; other elements, gases, materials etc that more easily change / burn / leave / dissipate do leave the bean as it roasts, leaving the percentage of caffeine in the bean growing higher the darker you roast.
Take two beans that were identical in size and weight when “green” (before roasting). Then roast one to City (medium), and roast the other to French (dark). The French roast bean will have virtually identical amount of caffeine, by weight, to the City bean, BUT, the French roast bean will be about 10% lighter in its whole weight because other things in it have burned off or converted to other things (like lighter gases). Because it is lighter, you would use 10% more of them to deliver the same weight of ground coffee, as compared to the City roast. That means your sampling of a dark roast, by weight, would have roughly 10% more caffeine than the City roast of the same sample weight size.
Short answer? Dark Roast, bean for bean, has more caffeine than a City (or Medium) roast.
Myth #3: More Caffeine in Coffee Means More “Bold” Flavours
Caffeine does NOT contribute to “bold flavours” in the cup. Caffeine, in its purest form, is one of the most bitter tasting substances science knows of. This isn’t me saying this, this is the FDA saying this, and the FDA actually advises using pure caffeine as the element in the bitter portion of their sensory skills testing (testing a person’s ability to distinguish sweet, sour, salty and bitter). Bottom line? Caffeine contributes bitterness (not necessarily a bad thing, as bitters balance with sweets and fats and oils in the coffee).
Bold? Gah, I hate that descriptive for coffee. Bold, schmold.
Myth #4 An Espresso Drink Has More Caffeine Than Brewed Coffee
Okay, this here is a truth: It is true that if you drank 12oz of espresso (6 full doubles, made from 18g of coffee per double brewed, aka 108g of ground coffee total), you would have more caffeine in the cup than a 12oz cup of coffee. But we don’t drink espresso that way. Before I get into this, please excuse my mix of metric with US measurements — my audience is primarily American.
So we don’t drink espresso that way. Instead, we drink espresso as a single shot (70mg ±5mg) of caffeine on average from arabica beans), a double shot (140mg, ±10mg), or as a quad for the people who want a bigger serving (280mg, ±20mg).
We also drink espresso as an americano (a 4–5oz beverage using 1oz of espresso, so that’s still 70mg of caffeine), a double americano (140mg caffeine for 6–8oz beverage), or as a single or double cappuccino 70mg or 140mg of caffeine) or a big giant Vente from Starbucks which uses two doubles usually (280mg of caffeine).
Brewed coffee on average — made from Arabica beans, because Robusta has almost 2x the caffeine — has about roughly 20mg (±2mg) of caffeine per ounce of liquid. Not much, right? Well, your 12oz “small” cup has 240mg… not much less than a quad espresso. 16oz? 320mg of caffeine in it. 20oz Venti at Starbucks? A whopping 400mg of caffeine, or more (chem labs have analysed the caffeine content of Starbucks house brew in 20oz size, it’s around 415mg).
There’s a few reasons for this. Espresso is a fast brew process, and only extracts about 75% of the stored caffeine in the grounds. Slower brewing methods like Chemex, pourover, drip, etc, extract 95% or more. Espresso is in essence a concentrate, so it’s going to have more of… well, everything, in a smaller amount. But we don’t drink 20oz of espresso (brewed normally, where we use 18g of coffee to brew at most 2oz of liquid).
We do however drink 20oz Ventis of brewed coffee. Well, I don’t — the biggest cup in my house is a 10oz cup for coffee — but many do. And that’s a 400+mg hit of caffeine, vs the 280mg a Starbucks Venti cappuccino has.
Long story short? A 12oz brewed cup of coffee will always have more caffeine than a 12oz americano or a 12oz cappuccino. Always (unless you used decaf in the brewed coffee).