What Changes the Caffeine in Chai: The Leaf, the Boil, the Milk and the Cup

All true tea, whether black, green, white or oolong, comes from the same plant, Camellia sinensis, and the dry leaf of each holds broadly similar caffeine. What differs is how much of it ends up in your cup. Tea 101 notes that dry tea leaf actually contains more caffeine than coffee beans, but only part of it is drawn out when tea is brewed, while coffee gives up much more.

Chai is usually made with CTC, whose small, hard granules brew fast and strong, which is why it suits milk and spices. Our blog traces its arrival in Indian markets to the 1960s, when it caught on because it was economical and could bring aroma, taste and color “within seconds of boiling.” Our own chais use a mix of two CTC grades, BP (Broken Pekoe) and BP1, chosen because the smaller grain allows a quicker, more robust infusion.

Grain size matters for caffeine too. Tea scientists at the Tocklai Experimental Station in Assam found that “smaller grades had higher caffeine content than larger grades,” and that in normal brewing around 80% of the caffeine in the leaf is extracted. The same review found the bud holds the most caffeine, with each older leaf holding less, and that caffeine in Assam teas peaks in June and July.

Strength is also a choice. A karak (kadak) chai, made deliberately strong with extra leaf and a long boil, will carry more caffeine than a light, quick cup. More on the leaf in Orthodox vs CTC tea.

Our 2016 Still Steeping piece on caffeine put black tea at around 20 mg after two minutes and around 50 mg after five. Its author, Peter G. W. Keen, also shared his own trick for a lighter cup: take about 30 seconds off the suggested brewing time. He wrote that most black teas carry a 4 to 5 minute recommendation and that he usually tried 3 to 3½. A reader added that he takes up to a minute off the suggested time for Assams, to avoid an “almost-bitter” taste.

Chai is often simmered rather than steeped, and the longer it bubbles on the stove, the more it extracts. Our own chais suggest a short, measured boil:

1. Bring 180 ml (about ¾ cup) of water to a boil in a pan.
2. Add 1 teaspoon of chai and simmer for 2 minutes.
3. Add ½ cup of milk and simmer for another 2 to 3 minutes.
4. Sweeten to taste, stir, and strain into your cup.

For a gentler cup, use the lower end of each time, or try the steeping method from the same instructions: 1 teaspoon of chai in 180 ml of boiled water for 5 minutes, then strain and add a dash of milk. Our tasting team’s steeping sheet brews Teabox Kadak Chai at 95 to 100°C (203 to 212°F) for 5 minutes, and Wayanad Cardamom Chai a little cooler, at 90 to 95°C, for the same 5 minutes. The full method, with spices from scratch, is in How to make masala chai at home.

Can you rinse the caffeine out?

No, not in any useful way. When a reader asked about pouring off a first infusion to “decaffeinate” her tea, Peter Keen replied that it “doesn’t seem to work”: he had read that you would need to let the leaf steep for about five minutes before pouring the water off, and when he tried it, the tea “seemed just a little flat.”

Brewing research explains why. A German study of consumer brews found caffeine dissolves much more readily than the other compounds in tea, with up to 55 to 90% of it extracted in brews of up to two minutes. So a short rinse takes away part of the caffeine and a good deal of the flavor, and a long one leaves you little chai to drink.

What changes is the water. Our tasting team’s steeping sheet uses one teaspoon, about 2.5 g, for 150 ml of water for every chai, and one version gives our Rajasik Ayurvedic Chai a teaspoon and a half. Our staff training deck uses the same 2.5 g in 180 ml, matching the method on our product pages.

The difference looks small, but it is about a fifth more leaf for each milliliter of water, and the caffeine follows the leaf. For a strong morning cup, use the full teaspoon in less water; for a lighter one, use a level teaspoon in the larger pour and keep the simmer short.

If milk takes the place of some of the water, each cup is a little less concentrated. But the caffeine in the pot is set by the leaf and the brewing time, not by how milky the result is.

Milk is also why chai uses strong CTC in the first place. Our 2018 staff training manual says masala chais “are to be thick, with aromas of spices, sweetened with milk,” and our 2023 training deck calls CTC the “ideal base for preparing masala chais,” usually taken with milk. A tea weak enough to drink black would taste thin once the milk goes in, so a chai base has to be bold, and that boldness comes with its caffeine.

Mumbai’s answer to a long day of chai breaks is the cutting chai: a glass filled only halfway, because a full cup at every break was too much. Half the glass, roughly half the caffeine. A big café mug, by the same logic, can hold well over a standard cup. Read the story in Bombay’s Lifeline – Cutting Chai.

Our Bombay Cutting Chai takes its name from that half glass, “cutting” meaning a half cup, and blends cardamom, ginger and fennel with CTC black tea. Counting cups is the simplest way to keep track: at about 50 mg a cup, three standard cups of chai come to roughly 150 mg, and three cutting glasses to about half that.