Most people have no idea what the real differences are between single and double shots. It’s not nearly as straightforward as you may imagine (and coffee shops don’t do a great job at helping you figure it out either).

When I managed a specialty coffee shop, being able to explain the difference to my coworkers was important to me - I wanted them to be skilled and knowledgeable. So I had to work through the differences in detail myself. And I was, frankly, shocked at how complicated it was.

But I don’t say this to scare you away - you’re going to learn much faster than most people because I’m going to explain single vs double shots in two ways:

• The easy, over simplified way
• And the complicated, frustrating way

If you’d like to explore the depths of this question, you can. But if you just want a basic understanding, you can stop after the next section

Ready to jump in?

Single VS Double Shots: The Easy Explanation

What I’m about to say is a bit of an oversimplification, but it’s suitable for most coffee lovers on a practical level.

Traditionally, a single shot (solo) of espresso uses 7g of espresso-fine grounds and yields about 30ml of espresso (about 1 liquid ounce). Weighing shots is a relatively new practice, so most baristas in the last 80 years or so have just used eyesight to judge when the shot was finished.

Starbucks popularized the double shot (doppio) in America in the 1990’s, though they weren’t its inventors. A double shot uses 14g of coffee and produces around 60ml of espresso (about 2 liquid ounces).

Double shots are now the standard in America and many places around the world. If you ask for a single, the barista will likely pull a double but use a split portafilter to halve the shot for you.

In terms of flavor, not really much changes. The introduction of double shots was really about increasing output and making it easier for busy baristas - but there’s usually not much difference in flavor.

According to coffeechemistry.com, one liquid ounce of espresso can have anywhere between 30 and 50mg of caffeine. That means that a double shot will likely have anywhere between 60 and 100mg.

Well, that’s about it for the simple explanation. And honestly, that going to be enough for most people. But if you’re extra caffeine sensitive or are curious about how this could get more complicated, you’ll want to read on.

Read: The Ultimate Guide to Espresso

Because what happens when you use 20g of coffee to pull a shot? Is it a triple shot?

Maybe. Maybe not.

Single VS Double Shots: The Complicated Reality

Ah, where to start…

In the modern specialty coffee industry, espresso ratios get a little funny. Though it wasn’t possible before, better equipment is allowing us to get more creative with how we pull our shots.

For example, the traditional double shot uses 14g of coffee and produces about 60ml of espresso. Seems simple enough, but we don’t like to use volume anymore to measure our shots.

We use mass (weight).

That 60ml of espresso includes a lot of crema, the golden-brown layer of foam that tops a well-pulled shot. When you let the crema fall apart and look at the liquid itself, it could actually just be 40-50ml of espresso.

This inconsistency is why we use scales to measure shots these days. We like to be precise. And that 60ml double shot of espresso? It probably weighs between 30 and 40g (we’ll say 35 for simplicity).

Read: The Golden Ratios in Coffee Brewing

Let’s bring it back so we can stay on the same page:

• 14g of coffee yields 60ml of espresso (2 liquid ounces) - visual measurement
• 14g of coffee yields 35g of espresso (1.2 mass ounces) - scale measurement

See? Both statements are true, but it’s getting hard to communicate what we really mean. There’s communication tension between the traditional measurement method and the more precise modern one.

And this is just the beginning.

3 Shops, 3 Shots - An Experiment

Let me show you a real-life situation I came across when I was training baristas.

• Shop #1 uses 16g of coffee. They produce 32g shots (around 50ml liquid ounces). 
• This is a 1:2 ratio (16g in, 32 out)
• Shop #2 uses 20g of coffee. They pull 40g shots (about 70ml liquid ounces). 
• A 1:2 ratio (20g in, 40g out)
• Shop #3 uses 20g of coffee. They pull 28g shots (about 30ml liquid ounces). 
• A 1:1.4 ratio (20g in, 28g out)

So here’s the question: which shop pulls double shots?

If you’re using the traditional definition, you’d know that Shop #1 is the closest, but it’s not exactly on the bullseye. The shop uses +2g of coffee but ends up with -10g of volume. Still, it’s closer than the other two shops.

Read: How To Read Coffee Packaging Like A Pro

So how do you describe the shots from Shop #2 and Shop #3?

It’s a trick question. They’re all double shots.

“But how,” you say, “They other two shots are very different from the traditional double shot!”

Right you are. The thing is, very few shops use the traditional definitions.

Modern Practical Definitions

Frustrated yet? Yeah, it’s really confusing. But we’re almost finished.

Specialty coffee shops these days have the ability to pull all sorts of wacky shots. Like I said earlier, new technology in scales, grinding, and espresso machines is making us more precise and giving us more flexibility with how we pull our shots.

That 20g in, 28g out shot from Shop #3 is actually very delicious. I’ve tried it myself. That Texas coffee shop called it a double shot, even though it used +6g of coffee and -30ml of yield compared to the traditional definition.

But why?

Because there’s really no reliable standard for single and double shots anymore.

Some shops say that their shots are double shots because they use more than 14g of coffee. Some say they pull double shots because they produce enough yield to split the shot in two with a split portafilter.

The definitions are all over the place.

And I love it.

Read: Want To Be A Coffee Aficionado? Here Are 5 Things You Need To Know

I love that it’s possible to have this much diversity in how we pull shots without losing quality. I enjoy the intense, small shots. I enjoy the smoother, bigger ones as well. As long as the flavors are ripe, crisp, and balanced, who cares what they call it?

But this does bring about a new challenge.

So How Do We Measure Caffeine?

Unfortunately, what we gain in flavor diversity, we lose in caffeine confidence.

At this point, there are zero studies that determine the impact that these diverse shot recipes have on caffeine. So, while I wish I could give you a clear answer here, I cannot.

Here’s what I can say.

Generally, caffeine comes out pretty early in the shot.

That means that the total yield only plays a small part in the total caffeine. What’s more important is the amount of coffee in the portafilter.

Read: The Best Time Of The Day To Consume Caffeine

So if a traditional double shot has anywhere between 60 and 100mg of caffeine, it’s likely that a modern double shot with more coffee grounds will have a bit more, since most shops use 16-20g of coffee in their doubles.

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I told you it got complicated, but it’s also fascinating. We’re living in an age where espresso recipes, techniques, and flavors are very diverse and very flavorful.

And yeah, it’s a bummer that the traditional definitions for singles and doubles has sort of lost their validity, but it’s a trade I’m willing to make.

If you’re a home espresso enthusiast, I highly suggest playing around with various coffee:yield ratios and grind sizes. You’ll be amazed at how different a single coffee blend can taste when pulled different ways.

But, of course, if you’re using lower-grade or old beans, you won’t have any fun exploring single and double shots because there won’t be any flavor to explore.

For the best cup of coffee, grind your beans fresh each morning with our JAVAPRESSE MANUAL BURR GRINDER!