5 Common Questions About Coffee Caffeine Answered

Written by: Garrett Oden

coffee caffeine

Have you ever ordered a mug of coffee because you didn’t want a shot of espresso in a cappuccino or latte to make you “bounce off the walls”?

As a former barista, I heard people say this all the time.

And I realized something: our cultural tropes around caffeine aren’t often realistic.

For example: A shot of espresso doesn’t normally have more caffeine than a mug of coffee - and it definitely doesn’t if that mug of coffee is a 16oz mug. Many people avoid espresso because they believe it has a wild amount of caffeine - except it doesn’t.

Let’s set the tropes and usual phrases aside. Let’s stop talking about caffeine as if it’s mysterious or mystical or unpredictable.

Let’s consult some science to answer our caffeine questions.

Does Espresso Or Black Coffee Have More Caffeine?

This questions not a difficult one, but the answer isn’t exactly straightforward. The confusing factor here is the serving size.

A standard mug of coffee in the US is 8oz, but espresso is only 1-2oz.

Read: What Is Espresso?

Many people ask whether 8oz of espresso or black coffee has more caffeine - but that’s not the right question to ask. Nobody is drinking 8oz of espresso, but everyone drinks 8oz of black coffee.

So here’s how we’re going to approach this: we’re not going to compare caffeine by volume, but by serving.

According to the National Coffee Association, an 8oz mug of regular black coffee can have anywhere from 65-120mg of caffeine, depending on the beans. Some estimates are higher, like 80-160mg.

For the sake of this article, we’ll say the typical caffeine content of black coffee is around 100mg per 8oz mug.

Espresso, on the other hand, generally has roughly 40-50mg per ounce. So for a standard 1.5-2oz shot of espresso in a specialty coffee shop, you’re looking at 60-100mg. Again, we’ll say the typical caffeine in a 2oz shot has around 80mg.

As you can see, an 8oz mug of coffee almost certainly has more caffeine than a 2oz shot of espresso.

However, there is a way you may be bouncing off the walls after all…

Since espresso has all the caffeine concentrated in a small amount of liquid, you’re able to drink it a lot faster than you would a full mug of coffee. And since you literally consume the caffeine faster, it hits you a harder, which is why espresso is usually associated with a more intense jolt of energy.

Read: Why You Need To Be Drinking Coffee Black (And How To Start)

But, in the end, espresso has less caffeine overall than a single mug (most of the time).

When Is It Too Late To Drink Coffee?

Your body naturally produces cortisol at different points of the day, giving you periodic boosts. For most people, the last cortisol boost is around 5:30 and 6:30 PM.

Though there are many different opinions from doctors about whether you should cut out caffeine completely after this last cortisol boost, a few things are certain:

  • Evening caffeine delays melatonin production, the circadian rhythm hormone that helps you into a deep sleep.
  • Caffeine as early as 6 hours before bed can eliminate up to 1 hour of quality sleep.
  • You may think caffeine doesn’t affect you at night, but you’re almost guaranteed wrong (no offense). We are terrible at diagnosing our own sleep quality.

coffee caffeine

You can read more about how caffeine disrupts quality sleep in this study from the Department of Psychiatry and Behavioral Neurosciences at Wayne State College of Medicine in Detroit.

If you really want to play it safe and ensure that caffeine isn’t bothering your sleep whatsoever, cut it off around 5 PM. For a more detailed look at coffee and sleep, check out The Best Time Of The Day To Consume Caffeine.

Does Hot Coffee Or Cold Brew Coffee Have More Caffeine?

Now this is one is fairly difficult to answer.

Almost everyone makes cold brew differently, which makes everything confusing. And some people drink cold brew at a high concentration, while some people enjoy it more diluted.

Sadly, there are no strong, conclusive studies on this question yet, however, we can look at the caffeine measurements of different ready-to-drink cold brew products and draw conclusions.

What does this chart, courtesy of Caffeine Informer, tell you?

Chameleon Cold Brew RTD Coffee

10 fluid ounces

270 mg caffeine

Starbucks Cold Brew Coffee

16 fluid ounces

200 mg caffeine

Stumptown Cold Brew Coffee

10.5 fluid ounces

279 mg caffeine

Stumptown Cold Brew + Milk

16 fluid ounces

319 mg caffeine

Califia Farms Cold Brew

16 fluid ounces

160 mg caffeine

Regular Hot Coffee

16 fluid ounces

326 mg caffeine

Here’s what it tells me: cold brew caffeine is all over the place.

It does look like, generally, cold brew coffee has a little less caffeine than hot coffee, but that’s not true 100% of the time, as is evident with the Stumptown Cold Brew Coffee.

Here’s what I normally tell people who ask this question.

It’s very difficult to make accurate guesses about caffeine in different cold brew coffee drinks. Therefore, it’s probably safest to assume that a cold brew drink has roughly the same amount of caffeine as a similarly-sized hot coffee drink.

Read: 5 Cold Brew Coffee Cocktails To Mix At Home

How Does Caffeine Affect My Health?

Yes! In quite a few ways, actually. Some of them are great, some are not.

Let’s start with the bad news first.

  • Caffeine is widely considered a drug-like substance. Anyone can develop a crippling dependency if they’re not careful, which can disrupt quality life and lead to withdrawls when caffeine cannot be consumed. If you intake more than a moderate 300-400mg per day, you can count on becoming seriously dependent.
  • Many people experience jitters and anxiety. Caffeine, as a powerful stimulant, causes many people to experience unusual jitters and anxiety - especially when the caffeine is paired with poor sleep.
  • Caffeine can irritate your digestive system. It can upset your stomach, irritate your bowels, and make you go to the restroom more than you’d like. However, sometimes this jumpstart to the digestive system can be a good thing.

Read: What Are The Differences Between Drip and Pour Over Coffee Brewers?

Now that those are out of the way, let’s move onto the positives.

  • Caffeine increases fat-burning during workouts. Caffeine triggers your blood cells to release fatty acids into your bloodstream. When you work out, this quick-and-ready supply of “fuel” gets used up quickly instead of being soaked back up later on.
  • Mental alertness is increased. Caffeine puts your brain on high alert, giving you more awareness and energy (though not necessarily better focus).
  • Your memory is given a temporary boost. You’ll have a slightly easier time remembering events that occurred while you were caffeinated, according to this study.

coffee and health

Is Coffee’s Caffeine Different Than Tea’s Caffeine?

Many people experience slightly different effects from caffeine when they drink coffee and tea. It’s not in their heads - there actually is a difference in how your body absorbs the caffeine.

First of all, tea generally has less caffeine than coffee - sometimes a lot less. Here’s a quick comparison of caffeine levels:

  • Black Coffee: ~100mg per 8oz mug
  • Black Tea: 20-80mg per mug
  • Oolong Tea: 10-60mg per mug
  • Green Tea: 10-40mg per mug
  • White Tea: 10-35mg per mug

Read: Searching For Certified Organic Coffee - Is It Worth It?

So, from the start, tea gives you less of a jolt than coffee.

But that’s not all.

Tea also has another chemical compound called L-Theanine in it. It soothes your nerves, calms anxiety and stress, and boosts focus. It also causes you to absorb the caffeine more slowly over a longer period of time.

So, when caffeine and L-Theanine are paired, the harsher edge from the jolt is smoothed out, the rise from caffeine is more smooth with a less severe crash, and your increased awareness is refined by improved focus.

They make a great pair.


Caffeine’s great, but the boost is really only a small part of the coffee experience. The aromas, rich flavors, mouthfeel, and even the act of brewing are all part of the daily experience that brings us happiness and helps us thrive.

Don’t settle for mediocre happiness by settling for mediocre coffee.

Get freshly roasted, specialty-grade coffee beans delivered to your door from some of the best coffee farms in the world as a member of our JavaPresse Coffee Club. We roast and ship our beans on the same day so that you can enjoy your daily brew while the beans are at peak freshness (and flavor).

It’s the best and easiest way to explore a variety of beans (or choose your favorite) from around the world that have been well-cared for from bean to mug.

Check it out!