I am writing this article as the most frequent questions my customers ask me is
Which tea contains the least caffeine?
Some are convinced that green or white teas contain less caffeine than black, or even none at all.
Let's try to bring clarity to this controversial issue. First of all
What is caffeine?
Caffeine is an insecticide that the tea plant, Camellia Sinensis, develops as a defence from insect’s bites and harsh weather.
Chemically, caffeine is a member of the xanthine family. It is a stimulant, it is odourless, has a bitter taste and is highly soluble in hot water. Caffeine occurs naturally in more than 60 species of plants across the globe including the seeds of coffee beans, cocoa beans, kola nuts, the leaves and buds of tea, the leaves of yerba mate, the bark of yoco, guarana berries and guayusa. Foods and drinks that are made with any of these ingredients or have caffeine added to them also contain caffeine: chocolate, coffee, energy drinks, and a cup of tea.
How much caffeine does a cup of tea contain?
The simple answer is: it depends!
There are two main variables that influence the caffeine content of a cup of brewed tea:
The type of leaf and the tea preparation method.
Type of leaf:
On average, tea leaves contain 3% caffeine by weight, although this can range from 1.4% to 4.5%. Many factors determine the caffeine content in the dry leaf, such as soil chemistry, altitude, type of tea plant, position of the leaf on the tea bush and cultivation practices.
The young bud and first leaf generally have slightly more caffeine than leaves in the lower part of the bush. The younger the tea leaves, the more caffeine will be produced in the tea. The most prized part of tea are the terminal bud and the adjacent two leaves, also called the tea flush. They are the sweetest and most beneficial, but also contain the most caffeine.
The leaves from the small leaf China tea plant (Camellia Sinensis) tend to have lower caffeine levels than the leaves from the large leaf Assam from India (Camellia Sinensis Assamica).
One factor that does not impact caffeine level is the level of oxidation (i.e. black tea is fully oxidized, green not oxidized, oolong partially oxidized, white tea slightly oxidized).
Therefore, tea colour is not an indicator of caffeine levels.
We are deceptively led to think that a cup of black tea has more caffeine than a pale one. That’s not true; Gyokuro, the top level Japanese green tea, contains more caffeine than a black tea such as Lapsang Souchong. High grade teas are made from the bud and two adjacent leaves (the tea flush), where the caffeine content is highly concentrated.
ALL TEAS CONTAIN CAFFEINE!
No one category of tea has more or less caffeine than another. It all depends on the particular tea in question. Even decaffeinated tea has a small amount of caffeine.
But the way we prepare our cuppa can make the difference as we are going to explain below.
Preparation method:
The amount of leaf, the leaf particle size, water temperature, steeping time are different variables that can affect caffeine content.
When tea is brewed in hot water for a longer time more caffeine is drawn out of the leaf into the liquor.
When tea is brewed in cooler water for a shorter period less caffeine is drawn out of the leaf into the liquor.
So, generally, black tea liquors contain more caffeine than green tea liquor as we tend to steep the black tea leaves in hotter temperature (100°C) than green tea leaves a (60°/80°C) and for longer time (3-5min for the black, 1-2min for the green).
A smaller leaf tea will release more of its caffeine than a larger leaf tea.
To have an idea here the ranges of caffeine content for an average cup of tea (230ml) made with loose leaves according to scientific studies:
Black Tea: 25 - 110 mg
Green Tea: 30 - 50 mg
Yerba Mate: 65 - 130 mg
www.healthline.com/nutrition/caffeine-in-green-tea
How to lower the amount of caffeine in a cup of tea? Here are some tips:
- Buy green tea or oolong tea if you are sensitive to caffeine, brewing it at maximum temperature of 70°C/80°C for no longer than 1/2min (always check the instruction of the producer, some Japanese teas should be brewed at 40°C/50°C ).
- Buy Keemun. This Chinese black tea has a lower caffeine content than other black teas, with an average of about 30-45mg per 8oz cup. Our keemun is particularly subtle, perfect to enjoy before bedtime or for those sensitive to caffeine https://trulyteashop.co.uk
- Throw away the first infusion. I know it sounds weird, but caffeine is quicker to dissolve than the other tea compounds. Up to 70% of the caffeine soaks within the first five minutes. The length of the first infusion can affect the strength of the second infusion (the longer the infusion, the blander the next), but also the lower the caffeine level. Try a good compromise finding the longest first infusion time that still preserves enough tea flavour for your liking.
- Avoid tea bags. Tea bags contain more caffeine than loose teas, as well as a inferior flavour and benefits. When possible, try to buy loose green tea leaves. You can use the same high-quality leaves three times, so after you've thrown out the first infusion, you still have two more cups of good quality tea to enjoy.
- Adjust the quantity. Buying loose leaf tea will allow you to adjust how many leaves you want to brew. Most people use approximately one to two teaspoons of loose leaf tea per cup, you can try cutting that in half. If the resulted brew is too weak, increase it little by little.
- Drink your tea hot. Tea contains catechins (antioxidants) and theanine (which give sweetness and freshness) that reduce caffeine activity. When tea leaves are brewed in hot water these molecules combine with caffeine, rendering the caffeine less effective. If you let it cool off too much after brewing, the catechins break down and more caffeine is released (even for the green tea do not choose types that should be brewed with water temperature under 70°C).
You should also know
- If you are pregnant or have a medical condition and have been advised to reduce your caffeine intake, consult with your doctor before consuming tea on a regular basis.
- Don't go overboard. Experts recommend consuming no more than 300 milligrams of caffeine a day. i.e. Don't drink more than 10 cups of green tea per day.
If you are intolerant to caffeine start slowly. Try your tea in small doses, start with a half of a cup per day and increase the amount gradually, observing your reaction to the increase and adjusting accordingly. If you feel calmly stimulated and content, you will know that tea works for you!