If you’re trying to cut down on caffeine, going from coffee to tea might seem like a logical choice. Tea offers other benefits, including compounds that protect your cells against oxidative damage and inflammation.
The thing is, not all teas are the same — if you’re trying to limit your caffeine consumption, it’s essential to pay attention to what you’re drinking.
Where does tea come from?
“Tea” can be a bit of a confusing term. Technically, it only refers to infusions made from the leaves of the Camellia Sinensis plant cultivars. This means that herbal teas aren’t tea. They’re a tisane or an infusion or decoction of herbs other than C. Sinensis.
Infusion involves steeping plants in hot water and is usually used for leaves, flowers, and other soft or delicate plant parts.
Decoction involves boiling plants for a longer time and is typically reserved for medicinal teas made of roots, bark, seeds, and other rigid, woody elements.
With that in mind, all of this points to one interesting fact: Black and green tea are both the same parts of the same plant. They’re each C. Sinensis leaves, though their cultivars may vary.
The only real distinction between them is how they’re picked and handled.
What’s the difference between types of teas?
If you’ve seen bagged or loose-leaf tea before, you know that it isn’t made of freshly-picked leaves. Tea leaves are selected at various stages of growth, dried, and, depending on the type of tea, oxidized, smoked, or both.
This yields all of the different types of tea on the market:
- Black teas are very oxidized. The leaves are picked, allowed to wither, then rolled or crushed. This breaks down the cell walls to speed up the oxidation process. Once the leaves have oxidized and darkened, they are heated.
- Oolong teas are the halfway point between black and green tea. The leaves are picked, allowed to wither, then are rolled and heated (sometimes with charcoal smoke for flavor). The heating stops the oxidation process partway through, yielding a lighter than black tea.
- Green teas are less processed than black. The leaves are picked and immediately dried via heating. This cuts down the time window that the leaves have to oxidize, so they stay green.
- White teas are the least processed. They have the lightest color and most delicate flavor. The leaves are picked while the buds are still tightly enclosed and aren’t rolled, crushed, or otherwise altered.
Which has more caffeine, black tea or green tea?
When it comes to caffeine content, black tea is typically regarded as having the most. The words “typically regarded” are here for a reason — a lot of factors go into determining how much caffeine ends up in your cup, and the type of tea is only one of them.
In general, black tea can have as much as 60 milligrams of caffeine per cup. Green teas contain about half of that. (White teas generally have the lowest caffeine content, at only about 10-15 mg per cup.)
This is only true if all other factors are equal. If green tea contains more buds, while black tea comprises only unbroken leaves, green tea may very well have more caffeine.
Cheap bagged teas are also typically made using broken leaves and dust that isn’t suitable for more acceptable grades of tea.
The increased surface area and ruptured cell walls of damaged leaves and dust allow more contact with hot water, which lets more caffeine steep into the finished beverage. Then, an inexpensive bagged green tea may have more caffeine than a fine loose-leaf black tea.
Steeping time impacts things, too. The longer the leaves are in contact with water, the more time there is for caffeine to infuse into the tea. Black tea has the longest recommended steeping time, which means more caffeine.
If you’re trying to go for the biggest caffeine hit, then a black bagged tea may do it. If you’re trying to limit your caffeine consumption, go for a loose white or green tea made of unbroken leaves instead.
Does the color of the tea indicate its caffeine content?
When looking at most bagged or loose teas, it’s easy to assume that the darkest teas contain the most caffeine. You’ll usually be correct, but it isn’t true in every case.
A type of tea called pu-erh undergoes a unique aging and fermentation process. This exposes the tea to cultures of microorganisms to enhance its flavor and health benefits. Its caffeine content can vary widely based on type, age, and fermentation method.
There are two types. One, raw pu-erh, is processed similarly to green tea before being aged. The other, ripe pu-erh, is processed like black tea and undergoes a unique fermentation process.
Ripe pu-erh’s fermentation speeds up aging, which doesn’t give caffeine as much time to break down. Raw, aged pu-erh generally has about half of the caffeine as ripe pu-erh, but can still have a rich flavor and dark color. The longer the tea ages, the less caffeine it will have.
Is decaffeinated tea worth it?
Caffeine isn’t the only difference between black and green tea. If you need to reduce your caffeine intake but love the taste of black tea, then choosing a variety that has been decaffeinated will help. You’ll still get all the bold, earthy flavor of black tea, but with less caffeine.
However, it should be noted that decaffeination doesn’t remove all of the caffeine. There will still be a small amount remaining in the finished beverage. For most commercial brands of decaf tea, you’re looking at a roughly 99% reduction compared to untreated tea.
Can hot water remove caffeine from tea?
There’s an idea that you can naturally decaffeinate your tea by steeping it in boiling water for 30-45 seconds, discarding this first steep, then brewing your tea as you would normally. Unfortunately, this process for DIY-decaffeinating your tea is primarily an old wives’ tale.
Caffeine is water-soluble, but it takes more than a brief dip to remove an appreciable amount. Studies show that tea can keep releasing caffeine for 8-10 minutes, so a quick 45-second dip isn’t going to make much of a dent.
What’s worse, attempting to decaffeinate your tea using hot water can end up removing a lot of the antioxidant content (not to mention the volatile compounds that give it flavor). The result is a flat-tasting, weak (watery) tea that still has almost as much caffeine as it did, to begin with.
A lot of chemistry goes into getting rid of tea’s caffeine while still leaving the flavor and health benefits intact. Some methods involve solvents like methylene chloride or ethyl acetate, then removed from the finished tea.
Another way uses carbon dioxide. The CO2 is placed under intense pressure to compress it into a liquid form, and it’s then used as a solvent. Once the process is finished, it just returns to its gaseous state.
In all of these methods, caffeine bonds to the molecules of the solvent used, but the antioxidants and volatiles don’t.
So, which is a better choice for the caffeine-conscious consumer, green or black tea? The final answer is: It depends. As a rule, black tea has more caffeine than green.
The amount of caffeine that ends up in your drink is determined by several factors, so if trimming stimulants is crucial for you, you’ll also want to pay attention to the leaf quality and steeping time. If all else fails, there’s always decaffeinated tea.