Most people have an opinion about it!
Some of us require a dose (or two!) before facing our day whereas others avoid it. And many of us—to ensure that we aren’t counting sheep all night—eschew caffeine in the evenings.
So, How DO You Get Caffeine Out of Tea?
Actually, it’s rather tricky.
Tea’s caffeine rival—coffee—is a bit more straightforward in this regard.
Caffeine is removed from coffee beans before they are roasted, and it is the roasting process that heavily contributes to the flavor of coffee.
For tea, however, the caffeine is removed after the tea leaves have been processed, which means that the decaffeination process directly impacts flavor.
There are several ways to remove caffeine from tea—and here we are talking about black/green/oolong/white/yellow teas, all produced with the leaves of the Camellia sinensis plant:
- methylene chloride (banned in the U.S.)
- ethyl acetate (can leave a “chemical” taste)
- water processing (can result in a “watered down” tea)
- carbon dioxide (CO2)
This last method—using naturally occurring CO2—results in a decaf brew that retains a lot of those health-benefit-providing polyphenols and retains much of the flavor.
How the CO2 Method Works
First identified in the mid-1700s, CO2 in gaseous form is an essential part of the earth’s atmosphere.
When CO2 turns into a solid, it is called dry ice because it sublimes, or goes directly from gas to solid form, skipping the liquid step.
Under high pressure and temperature, it goes into a supercritical state, having both gas-like and liquid-like properties. In this state, it is used to decaffeinate tea because its small molecules attract the small caffeine molecules. The resulting linked CO2–caffeine is then filtered out, leaving both the flavor and the polyphenols of the tea largely intact. The CO2 is reused, and the extracted caffeine is used in soft drinks and medicines.
Why Aren’t There a Lot of High-Quality Loose Leaf Decaf Teas Around?
Even though the CO2 is reused, this process is more expensive than the other methods. Therefore, teas decaffeinated by CO2 are generally limited to some basic black and green teas that serve as the base for flavored teas.
Further, decaffeinating any beverage by any method adds both time and cost to the product. So if the demand isn’t high, there isn’t much incentive to offer a large variety.
And actually, the demand isn’t very high, especially in Europe. And since Germany carries out much of the CO2 decaffeinating . . . well, there is little incentive for decaffeination.
Additionally, because removing caffeine does impacts the tea’s qualities (caffeine affects flavor, after all), the highest-quality teas are rarely if ever decaffeinated.
Decaf Does Not Equal Caffeine-Free
It should be noted that decaf does not mean caffeine free: a small amount of caffeine always remains after the decaffeination process. For a totally caffeine-free “tea,” you need to bypass Camellia sinensis and reach instead for rooibos, honeybush, fruit, and many herbals.
Oh and BTW, You Cannot Decaffeinate Your Own Tea. Period.
That whole oft-repeated thing about throwing out your first brew and instead drinking the second “now-decaffeinated” steep?
Nope, won’t work. At all. End of story.
You’d have to brew your tea for a really long time to remove enough caffeine to make a difference, and since caffeine and flavor go hand-in-hand, you’ll basically just have some flavorless, colored water.
So if you’re sensitive to caffeine, find some high-quality decaf tea, or go the naturally caffeine-free tisane route.