How is Tea Decaffeinated: Caffeine Removal Methods

Jill Caren

Tea decaffeination is a process used by tea manufacturers to extract caffeine from tea leaves. This allows tea drinkers to enjoy the flavor and beneficial …

Categories Tea

Tea decaffeination is a process used by tea manufacturers to extract caffeine from tea leaves.

This allows tea drinkers to enjoy the flavor and beneficial compounds of their favorite tea without the caffeine’s stimulating effects.

Key Highlights

Decaffeinated tea is not caffeine-free; there are always trace amounts of caffeine.
Solvent-based decaffeination, CO2-based decaffeination, and water-based decaffeination are the three most common methods that tea brands use to make decaf tea.
It is not possible to fully remove caffeine from tea at home.

In this post, we’ll look at the different methods for removing caffeine from tea, the pros and cons of each process, and what teas are naturally caffeine-free.

So grab your favorite cup of tea and let’s get started!

What is Decaf Tea?

Decaf tea is a type of tea that has had most of the caffeine removed from it. Decaffeinated tea is NOT caffeine-free.

Herbal teas, which are naturally caffeine-free, could be something to consider if you’re looking for a caffeine-free tea.

The decaffeination process always leaves a trace of caffeine in the tea leaves. Tea marked “decaf” is required by law to have less than 2.5 percent of its original caffeine level, which generally corresponds to less than 2 mg per cup.

In general, decaf tea typically contains less than 2–5 mg of caffeine per 8-ounce serving (240 ml).

This is significantly lower compared to the caffeine content of regular true tea (black, green, oolong, pu-erh, and white), which ranges from 15 to 80 mg per 8-ounce serving, depending on the type of tea, how it is prepared, quality, etc.

Any type of tea can be decaffeinated; black and green tea are the two types that tea companies decaffeinate most due to their popularity.

How is Tea Decaffeinated?

Tea is decaffeinated using several industrial methods, each with its own set of pros and cons. The most common methods are:

  • Solvent-based decaffeination
  • Carbon dioxide (CO2) decaffeination
  • Water-based decaffeination

Solvent-based decaffeination (methylene chloride or ethyl acetate)

Methylene Chloride Decaffeination: This is an old-fashioned process in which the tea leaves are steamed and then washed with methylene chloride (direct method) or the tea leaves are soaked in hot water to release the caffeine before being combined with the solvent.

The solvent binds to the caffeine molecules, isolating them from the other water molecules. The caffeine-free water is then reabsorbed by the tea leaves, while the caffeine-solvent solution is filtered out and evaporated.

Pros: This method is inexpensive and doesn’t affect the original tea’s flavor.

Cons: There is always the risk that the solvent will leave a residue on the tea leaves. Some countries prohibit the importing of tea that has been decaffeinated with methylene chloride.

Due to concern over residual solvent, most decaffeinators no longer use methylene chloride.

Ethyl Acetate Decaffeination: This process of removing caffeine from tea is frequently called “natural decaffeination” as ethyl acetate is naturally found in tea leaves.

Although it occurs naturally in tea, the ethyl acetate used in tea decaffeination is made chemically.

The method is identical to that of methylene chloride.

Pros: Ethyl acetate is a low-cost, effective caffeine solvent that may extract a large quantity of caffeine from tea leaves.

Cons: While ethyl acetate is selective for caffeine, it is possible that it will remove other components from the tea leaves, which may change the flavor or other qualities of the decaffeinated tea.

CO2  Decaffeination

This is the most natural and eco-friendly process of tea decaffeination. Most of the higher-quality loose-leaf teas and tea sachets are decaffeinated through this method.

Also known as the “supercritical carbon dioxide” method, this process uses pressurized CO2  to extract the caffeine from the tea leaves. 

Supercritical carbon dioxide (CO2 ) is a fluid state of CO2  that is heated and kept at or above its critical pressure and temperature.

The CO2  is heated and pressurized until it reaches a “supercritical” state, then passed through the tea leaves, where it effectively extracts the caffeine while leaving behind other compounds such as flavors and aromas.

Pros: This method best preserves the tea’s beneficial compounds. It’s also non-toxic, and it’s the only decaffeination process approved for “Certified Organic” decaf teas.

Also, the supercritical CO2  decaffeination process eliminates practically all of the caffeine, up to 97%. It’s impossible to remove 100% of the caffeine from tea leaves that are naturally caffeinated.

Cons: The CO2  extraction process and equipment are expensive, resulting in a higher price for decaffeinated tea. 

While CO2  extraction is usually considered a mild approach for preserving tea flavor, some small modifications in flavor may occur during the decaffeination process.

Water-base decaffeination

This tea decaffeination process uses hot water to extract caffeine from tea leaves.

The tea leaves are soaked in hot water to remove the caffeine, and then the solution passes through a carbon filter to remove the caffeine. The decaffeinated water is then reinfused with the tea leaves, producing decaffeinated tea.

Water decaffeination is more often used to decaffeinate coffee beans, and just a few tea brands use it for loose-leaf tea.

Pros: This is a low-cost, gentle process that doesn’t involve the use of harsh chemicals.

Cons: It is not as effective as other methods at removing caffeine and is not suitable for all tea types. The primary downside of this method is that it has a huge effect on tea’s flavor, resulting in watery flavors.

Decaffeinating Tea at Home

You can’t decaffeinate your tea at home. You can use some techniques to reduce the caffeine by a small percentage, but you can’t remove the whole amount of caffeine from the tea leaves.

To lower the caffeine levels of your favorite tea, you can:

  • Brew it at a lower temperature
  • Steep the tea for a shorter period
  • Use fewer tea leaves
  • Make a second and third infusion

Don’t forget that all of these have an impact on the final tea’s flavor. Because this is an interesting topic, here is a detailed article on how to lower the caffeine content of tea at home.

Pros and Cons of Decaf Tea


Decaffeinated teas are an excellent choice for people who want to minimize their caffeine intake yet enjoy drinking true teas (black, green, white, pu-erh, and oolong).

Also, decaf teas can be consumed at any time of day without interfering with sleep (unless you are extremely caffeine sensitive).

These teas are now widely accessible in loose-leaf, tea bags, and tea sachet forms.


First of all, no matter what method is used, the decaffeination process changes the tea’s original flavor.

Furthermore, decaf teas often do not provide the same benefits as regular tea because when caffeine is eliminated, some of the beneficial compounds are also lost.

Some manufacturers use chemical solvents, which may be a concern for some people.

Also, decaffeinated teas are usually more expensive than regular teas.

Teas That Are Naturally Caffeine-Free

Naturally caffeine-free teas are made from a variety of herbs, fruits, and plants that do not contain caffeine and can be enjoyed at any time of the day.

Herbal tea with raspberries in a glass cup and glass teapot
Herbal teas are naturally caffeine-free

They are a great alternative for those who want to enjoy the delicious flavor of tea without the stimulating effects of caffeine.

With so many different flavors to choose from, here are some popular caffeine-free herbal teas:

  • Peppermint
  • Chamomile
  • Rooibos
  • Hibiscus
  • Lemongrass
  • Apple

Yerba Mate is an herbal tea that is naturally high in caffeine and can contain up to 80 mg of caffeine per 8-fluid-ounce serving, depending on how it is brewed.

Low-caffeine True Teas

All true teas (black, green, white, oolong, and pu-erh) are made from the same plant (Camellia sinensis), and they all contain caffeine. Some types of these teas contain lower caffeine levels than others.

The caffeine levels in true teas vary depending on the type of tea, harvest time of the leaves (mature leaves are lower in caffeine), tea grades, etc.

As an example, several Japanese green teas, such as Hojicha, Genmaicha, Kukicha, and Bancha, are low-caffeine green teas.

You can also find white tea that contains lower levels of caffeine, but be careful; some types of white tea are extremely high in caffeine.

It’s always best to ask your tea provider about the caffeine levels of your chosen tea if you want to choose low-caffeine tea.

The Takeaway

Decaffeinating tea is a complex process done by tea manufacturers. To extract the caffeine from tea leaves, manufacturers use several methods, such as solvent-based decaffeination, CO2 , or water.

Each of these methods has pros and cons. Usually, people choose teas that are decaffeinated with the CO2  method since it is non-toxic and best preserves the tea’s beneficial compounds.

Regardless of the method used to decaffeinate a tea, it’s important to note that these teas are not 100% caffeine-free. There is always some amount of caffeine in the tea leaves, usually less than 2–5 mg per cup.

If you’re sensitive to caffeine or want to completely eliminate it from your diet, opt for herbal teas, which are naturally caffeine-free.

In the end, I hope this article helped you understand what methods are used for tea decaffeination. You now know a bit more about this process, and you can make better choices.