How to make tea, the scientific way

I tend to prefer my tea without sugar, a request that often annoys tea vendors because they tend to keep pre-boiled milk ready with added sugar, and my request almost always requires them to put in a little bit of extra effort. I don’t complain because I am clearly in the minority in this part of the world.

When someone says they “don’t know how to make good tea”, what they are actually saying is they “don’t know how to make tea in exactly the way I like it”. When it comes to a beverage most Indians drink several times a day, the idea of “good tea” is subjective. Some like it milky, some swear by black, some prefer green, a few like it really intense, and several drink the beverage with an entire spice rack dunked into it. And the regularity of consumption results in a level of personal nostalgia and obsession with tradition that often translates into fierce possessiveness about how it should be made.

So, before we get down to the science of tea, let’s first pour some cold water on this notion that it’s a “traditional” drink. The only reason we drink tea today is because the East India Company illegally sold opium to the Chinese to buy tea to feed their addiction, and once they started cultivating a lot of it in Assam, they wanted to convince Indians to start drinking it to sustain their profits.

And the first thing we Indians did was to add spices to the beverage, because, you know, the 600 volatile flavour compounds in tea were clearly not enough. Interestingly, the Tea Board, which spearheaded the marketing effort to popularise this drink in the subcontinent, attempted to dissuade people from making masala chai back in the day because it tended to reduce the amount of tea leaves required per serving, resulting in less revenue for the tea companies.

With that bit of history out of the way, let’s get down to the science. When the leaves are dried and used as is, it’s called green tea, and if the leaves are fermented, it’s the tea Indians are more familiar with—black tea. The process of fermentation concentrates the amount of caffeine in the final product.

When we boil tea, the leaves infuse their flavour into the water, and the amount of infusion depends on a few factors—the freshness of the leaves, the temperature of the water and the duration of boiling. You should store tea in a cool, dark place in an airtight container to prevent loss of volatile aroma molecules and oxidation. The ideal temperature of the water varies according to the variety of tea you are using. Green tea, which is more delicate, is best boiled at 82 degrees Celsius, which is simmering temperature. And you should avoid boiling green tea for more than one minute or you will get more tannic flavours that are not very pleasant. When it comes to black tea, the temperature needs to be close to a rolling boil, about 92-95 degrees Celsius, and three-four minutes is optimal for getting maximum flavour out of the leaves without getting tannins into your drink.

On the touchy subject of when to add milk, it’s entirely a matter of personal preference. If you boil the tea leaves in milk, what you will get is a sweeter, thicker drink since milk loses water as you boil and thickens in texture. If you boil it in water and add the milk later, you will get a thinner drink. If you add spices like ginger, adding it when cooking the milk will get you a more intense gingery flavour than when adding it to the water. This is because spice flavour molecules dissolve better in milk fats than they do in water.

And if you are using dry spices, it’s best to roast and powder them coarsely before adding to the tea. There is no formula for masala chai —feel free to experiment. Again, cooking the spices in milk will extract more flavours.

If you are using a teabag, boil the water to close to 95 degrees Celsius (a rolling boil) and then let the teabag steep for at least five minutes. This will get you a richer, full-bodied taste. If you don’t like the stronger, more intense flavour, steep it for as little time as you want, but remember that what you are leaving behind is not just flavour, but also some of the antioxidants in tea that are good for you.

And when you serve tea, recent neurological research tells us that the colour of the mug you serve it in will make a difference in taste perception. Tea served in a red or pink mug will taste sweeter than tea served in a white or blue mug. This is because our brains tend to associate reddish colours with ripening fruits, and this is a good way to enjoy your tea without too much added sugar. So, no points for guessing what the colour of my mug is!

The British introduced tea to Indians. (Illustrated by Krish Ashok)
The British introduced tea to Indians. (Illustrated by Krish Ashok)
'Chai' recipes vary in every family. (Illustrated by Krish Ashok)
'Chai' recipes vary in every family. (Illustrated by Krish Ashok)
Temperature and time rules to make tea. (Illustrated by Krish Ashok)
Temperature and time rules to make tea. (Illustrated by Krish Ashok)
Instructions for milk and masalas. (Illustrated by Krish Ashok)
Instructions for milk and masalas. (Illustrated by Krish Ashok)
The science of tea cups. (Illustrated by Krish Ashok)
The science of tea cups. (Illustrated by Krish Ashok)

Krish Ashok is the author of Masala Lab: The Science Of Indian Cooking.