Tea
Decaffeinated Tea And What Leaves The Leaf
Removing caffeine from tea also removes aromatic compounds and some polyphenols, which is why decaffeinated versions taste softer and flatter than the same leaf untreated.
Decaffeinated tea is a smaller category than decaffeinated coffee and a harder technical problem. The processes involved take more than caffeine out of the leaf.
Caffeine is not conveniently isolated
Caffeine sits alongside polyphenols, amino acids and volatile aromatic compounds, many of which share similar solubility. A solvent that removes one tends to remove others.
Tea also contains far more delicate aromatics than green coffee does, and those are largely what makes a tea recognizable.
The result is that decaffeination costs flavor in a way that is difficult to avoid entirely. The question is which compounds a given process protects.
Carbon dioxide processing is the gentlest common method
Pressurized carbon dioxide behaves as a solvent that is fairly selective for caffeine. It leaves more of the polyphenol content intact than most alternatives.
The equipment is expensive and the process is slow, so it is used mainly for higher-value teas. Cost is the reason it is not universal.
Teas treated this way keep more of their character, though a side-by-side comparison with the untreated leaf still shows a difference.
Ethyl acetate processing is cheaper and blunter
Ethyl acetate occurs naturally in fruit and is used as a solvent for tea and coffee alike. It is effective and inexpensive.
It is less selective, taking a larger share of the catechins and aromatics along with the caffeine. The finished tea tastes noticeably softened.
Packaging sometimes calls this naturally decaffeinated because of the solvent's natural occurrence. The description is accurate and tells you little about the outcome.
Rinsing the leaf at home does not work
A widespread claim holds that a short first steep discards most of the caffeine. Caffeine does extract early, but a brief rinse removes only a modest fraction.
What the rinse does remove efficiently is aroma. The practice sacrifices much of the flavor for a small reduction.
Anyone avoiding caffeine for medical reasons should treat rinsed tea as caffeinated and rely on properly decaffeinated products or naturally caffeine-free infusions instead.
Herbal infusions sidestep the problem entirely
Infusions made from herbs, flowers and fruit contain no caffeine to begin with, because they are not made from the tea plant.
They taste nothing like decaffeinated tea, which is the point. Someone wanting the character of black tea without caffeine has to accept a treated leaf.
Which route suits depends on what is being sought. Replacing the ritual is easy, and replacing the specific flavor is not.
