How much caffeine is in coffee?

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According to Starbucks, coffee is the second most traded legal substance in the world (after oil).

While not quite accurate, there’s no denying the popularity of coffee around the world.

But recently, more and more people are asking one question: what’s in my cup? And that means caffeine content as well.

How many mg of caffeine is in your cup of coffee?

The amount of caffeine in your coffee will depend on a wide range of factors, as discussed in the next section.

However, the quick answer is as follows:

  • Espresso based drinks (e.g. flat white, latte, cappuccino) will have about 63mg of caffeine. This is based on a single shot of espresso, which is approximately 30ml in volume, so you can double that for a double shot.
  • For drip coffee, also called brewed coffee, the answer is around 100mg per 240ml cup.

As you can see, espresso has more caffeine per millilitre than drip coffee, but you’ll generally drink less of it at a time so you may in fact consume less caffeine in an espresso-based drink.

Factors that influence caffeine content in coffee

Coffee contains a variety of active molecules that contribute to its flavour, aroma and stimulant effects. These include caffeine, trigonelline, chlorogenic acids and diterpenes.

The amount of these compounds that end up in your final cup depends on the type of bean, where it was grown, how it was roasted, and how it is prepared.

Coffee bean variety: Arabica vs Robusta

If you’re looking for coffee that packs a punch, consider the Robusta bean. By weight, this bean contains more caffeine than an Arabica bean.

Robusta beans contain roughly twice as much caffeine as Arabica. Arabica beans will contain around 1.2% caffeine, which is roughly 12 milligrams of caffeine per gram of coffee. Robusta has a higher caffeine content with around 2.2% or 2.2 milligrams.

The caffeine content in a coffee bean relates to how dense it is.

Dense beans are the result of high altitude. Arabica beans are generally grown at high altitudes, while Robusta beans grow at a much lower altitude, so they are less dense.

This correlation between altitude, density, and caffeine, is thought to be because caffeine serves as a pesticide so it is only natural that Robusta beans contain more, as they grow in lower altitude areas that are more accessible to pests.

While Arabica beans have less caffeine, this type of coffee bean is considered to have better flavour and are used in most specialty coffees.

Grind size

A coarser grind will extract less caffeine than a finer grind will.

The finer the grind, the greater the surface area is exposed for the extraction of compounds, including caffeine.

Coffee-to-water ratio

The more coffee per water volume, then the more caffeine will be extracted from each bean during brewing.

A 1:15 ratio (one part coffee for 15 parts water) is a common starting point for methods like pour-over. From here, the coffee ratio can be increased to increase caffeine content.

Brew time

Caffeine is extracted from the coffee grounds into hot water, but it takes time for it to diffuse out. You’ll get more caffeine if you leave the grounds in contact with hot water for longer.

Therefore, the longer the brew time, the more caffeine will be extracted from each bean.

This applies to almost all brew methods. For example, the longer you run your espresso extraction, the more caffeine will be extracted from the ground coffee into your drink.

But this rule doesn’t always hold true. Brew methods that use cold water, such as cold brew, extract up to 30% less caffeine than other methods, even though the brew time can be between 12 and 16 hours. So, the water temperature does play a role also.

Keep in mind that immersion brewing methods such as French press allow the coffee grounds to be fully in contact with the hot water for a long period of time. This is in contract to say pour over or a drip machine, where the water flows through the grounds just once.

Serving Size

It should go without saying, but a bigger serving of coffee is going to have more caffeine.

Keep in mind that a double shot of espresso will have double that of a single and that an extra-large cup of filter or plunger coffee could contain more caffeine than you intended to consume.

Instant vs non-instant

Compared to regular coffee, instant coffee generally has slightly less caffeine.

In general, a one-cup serving of instant coffee made with one teaspoon of instant coffee powder contains 30–90 mg of caffeine; a cup of regular coffee made with may contain 70–140 mg.

As a reminder, espresso contains around 63mg per shot and brewed coffee around 100mg per 240ml serve.

RELATED: Is coffee acidic?

Does the darkness of the roast impact caffeine content?

The difference between lighter and darker roasts is that dark roast beans are roasted for a longer period of time at a higher temperature.

Some people fall into the trap of thinking that the darker, stronger coffee that comes from a dark roast would contain more caffeine, but this isn’t accurate.

Lighter roasts have more caffeine than darker roasts.

During the roasting process, caffeine and other compounds evaporate from the beans. The longer the roasting time, the more caffeine is lost from the beans.

However, the difference is not considered significant.

How much is too much?

According to the Mayo Clinic, for most adults, up to 400 milligrams of caffeine per day is not harmful.

But some people are more sensitive to the effects of caffeine and those who experience headaches, restlessness or anxiety, should ask their doctor if they should cut back on caffeine.

Ways to reduce caffeine in your coffee

If you want to reduce your caffeine intake but don’t want to give up on your daily cuppa completely, there are a few steps you can take:

  • Switch to decaf – this the most effective way to reduce your caffeine intake without stopping drinking coffee altogether
  • Use less coffee in each brew – as discussed earlier, more ground coffee beans = more caffeine
  • Try to stick to Arabica beans
  • Use a larger grind size
  • Reduce your brewing time
  • Try cold brew

Does Decaf coffee contain caffeine?

If you’re trying to cut down on caffeinated drinks but still want to enjoy your daily cup of joe, decaf can absolutely help, but if you’re expecting zero caffeine, unfortunately, you’re out of luck.

A typical cup of decaf coffee has about 2 mg of caffeine, compared to a typical cup of regular coffee, which has anywhere from 60mg – 100mg+ of caffeine.

Decaffeination reduces the amount of caffeine in coffee beans by about 97% or more.

The main benefit of drinking decaffeinated coffee is that you’ll be getting all the flavour and health benefits without the jitters and other side effects from drinking too much caffeine.

However, keep in mind is that there’s still some caffeine in decaffeinated coffee — just not very much.

The amount of caffeine in decaf coffee can vary based on the type and process used to decaffeinate it.

There are two main ways to remove the caffeine from coffee beans: solvent-processed and Swiss water processed.

In most cases, the process used is a solvent-based method. The two main types of solvents are methylene chloride and ethyl acetate.

These solvents dissolve the caffeine inside the bean, but not much else. This leaves all the other flavours intact.

The Swiss water processed coffees use a special process that filters out the caffeine through activated charcoal.

The best way to get an accurate measurement of how much caffeine is in your decaf coffee is to check with your barista or look at packaging labels.