THERE IS NO ‘X’ IN ESPRESSO

I just moved my Breville espresso machine into my office this week and figured I would take a second to talk about this misunderstood coffee drink. For starters, it’s ES-presso, not EX-presso—there has never been nor ever will be an ‘x’ in espresso.

Now that we know how to say it, we can discuss what it is. Many people have this idea (just like super dark, super bold coffee) that espresso is this crazy high caffeine beverage. What we need to realize is coffee and caffeine content has to do with the concentration of the solute. If you took chemistry lab you’ll remember molar concentration:

M = n/v

where M = molar concentration, n = moles of solute, v = liters of solution. But don’t worry we’re going to keep our math very simple here, this isn’t chem lab, just a little overview on espresso. For those of you who are new to reading my writings, coffee holds a special place in heart as I started a coffee roasting company in college that me and my buddies somehow managed to start selling in a cafes, restaurants, and grocery stores. Here’s a trip down memory lane:

If you’re curious just go to @roastedcoffeecompany on instagram. Moving right along.

Caffeine & Coffee

How much?

On average, green Coffea Arabica beans (the type of coffee bean we consume (Coffea Robusta being the other)) contain 0.9-1.1% caffeine by weight, which equates to ~8-12 mg/g of caffeine. This is where things get tricky… These are the numbers for green coffee. We roast the green coffee into the consumable product we know and love. On average the beans lose about 10-15% of their weight. So let’s just assume that we are getting around 8.75mg/g of coffee. This figure can be different based on how long the coffee was roasted for, the temperature that it was roasted at, etc.

The ratio

So we know roughly how much caffeine is in roasted coffee, now we have to consider the ratio. The ratio is how much water we’re using to brew how much coffee. If you’re buying a cup of coffee from a coffee shop, you don’t know what ratio of coffee:water was used. But there are some rules of thumb. For example, using a 1:16 (National Coffee Association guidelines) the numbers would look something like this:

1:16 — 8oz (224ml or g)/16g = 14g of coffee*8.75mg caffeine = 122.5mg

So in an 8oz cup of coffee, assuming the NCA standards were implemented, you can expect to have ~122.5mg of caffeine. But wait, what if they don’t use 1:16 but they use 1:18 or 1:14… let’s look at both:

1:18 — 8oz (224ml or g)/18g = 12.4g of coffee*8.75mg caffeine = 108.5mg

1:14 — 8oz (224ml or g)/14g = 16g of coffee*8.75mg caffeine = 140mg

As you can see, the numbers can change a decent amount depending on the ratio used. But at the end of the day nobody is going to go much higher or lower than 1:16 so average standard deviation of 20mg is pretty innocuous.

So, what Is espresso?

A great place to start is first defining what espresso is. Simply put: anything brewed via an espresso machine, is espresso. You’ve likely heard of Espresso roasts, but this gets to be a tricky topic in the world of coffee roasting because there are different fields of thought. Some believe an espresso roast would signify a very dark roast, however, you can brew espresso with a light roast coffee so that’s not a great defining factor. Also, some french roasts, or ‘Vienna’ roasts, are much darker than some individuals espresso roasts. This is where coffee becomes an art and gets to be very subjective.

There is one defining characteristic that some use to differentiate espresso roasts from filter roasts (filter meaning filter coffee: pour over, french press, aeropress, etc). That is length of roast time. See, espresso has a brew time of ~20-30 seconds which means the water needs to be able to pass through the grounds and penetrate the cells quickly. Green coffee contains a decent amount of water. Part of that 10-15% of weight it loses is water. This is necessary for the brewing process.

Some roasters will extend the roasting time of espresso roasts as to ‘dry out’ the bean. This allows for a more efficient brew during the fast pull (or short brew time) of espresso.

Espresso & Caffeine

Okay, so many people who drink coffee often make reference to espresso and how one shot of espresso and they’re bouncing off the walls. Well, as we’ve just discussed, we now know there’s nothing special about the beans. Let’s walk through an example. Take these same coffee beans we had earlier and make some espresso. A single espresso is typically 7-9 grams of ground coffee or 14-18 grams of ground coffee for a double shot. A single shot is 1oz and a double is 2oz. So let’s do some math again, expect you’ll see the ratio is much different:

9g of coffee*8.75mg caffeine = 98mg (ratio is 1:3 here)

18g of coffee*8.75mg caffeine = 157.5mg (ratio is 1:3 here)

So, the biggest take away here is that espresso is a far more concentrated coffee beverage when it comes to caffeine content given its brewed at a 1:3. However, that does not mean it has more caffeine than your cup of coffee. It depends on the size of your coffee, the type of bean, the ratio, the brew method, etc.

I’m hoping that cleared the air a little with regard to what espresso is and the differences between espresso, and ‘filter coffee’. Everybody responds differently to caffeine, but you can now put an end to those who claim they can’t drink espresso cause they’ll fly off the walls as I’ve heard so many people say.

Sometimes I like to put a shot of espresso in an orange Celcius. It’s traditionally called a ‘shot in the dark’ but when it’s an orange Celcius I’ve deemed it the ‘Citrus Cowboy.’ It’s for those of us who like to live life on the edge.

~ Bonde