The caffeine content in tea has been misunderstood and misrepresented for too long. Here, we'll clear it up with some science.
Caffeine in Tea
Do you know the difference between black tea vs. green tea, oolong, and white tea? All of these tea varieties come from the Camellia sinensis plant. They may come from different regions or tea gardens, but the leaf is the same. All tea leaves contain caffeine.
Caffeine levels in tea leaves vary slightly but will always be present. The brewed tea will also deliver a varied concentration of caffeine depending on the variety and the brewing method.
What is Caffeine?
Caffeine is a phytochemical found in plant sources like coffee beans, tea leaves, mate, and cacao. Ingesting caffeine has a stimulating effect on the nervous system and mind. Some people love caffeine due to its energizing effects. But, some individuals are sensitive to caffeine and choose to avoid it.
Is Tea Caffeine Different From Coffee?
Caffeine, as a chemical, is the same in different plants. However, reactions with concurrent chemicals can change the way it is processed. The result is that the drinker will experience caffeine in tea differently than in a cup of coffee.
L-theanine is an amino acid in tea that is not in the coffee bean. It has a calming effect, which may seem like a contradiction. But, studies consistently show that combining caffeine and theanine increases speed and accuracy and limits distraction.
Quantity of Caffeine per Cup
It is a common misconception that different tea varieties contain varying concentrations of tea. The Journal of Analytical Toxicology reports, "caffeine concentrations in white, green, and black teas ranged from 14 to 61 mg per serving (6 or 8 oz) with no observable trend in caffeine concentration due to the variety of tea."
Brewing time will be the most significant determining factor in how much caffeine is in your cup. The shorter the steep, the less caffeine. Brewed tea contains less caffeine than a cup of coffee, but white tea does not have less than black.
Herbal tea is a broad category that includes any botanical or plant infused in hot water. Most herbal teas are caffeine-free as they don't contain any tea leaves.
What Affects the Amount of Caffeine in Tea?
The temperature of the water and the length of steeping time have the most significant impact on caffeine content. The potency of caffeine in white, green, oolong, and black tea leaves is almost identical.
If you've been a long-time tea drinker, you've likely been miseducated with infographics and salespeople telling you that black tea has more caffeine and white tea has less.
But, if you were drinking the tea, you probably had a different internal experience than the information provided!
Pardon me as I break the fourth wall and speak from personal experience. In my tea career, I, too, was misinformed (and stating as fact) these miscalculations.
Your brewed mug may have less tea because you only brew it for 45 seconds. However, the concentration of chemical components in the leaves is likely the same.