A cuppa is an Australian institution. Whatever the season, it is how many of us relax, take a break or welcome a visitor. Ask 10 people how to make the perfect cup of tea, though, and you will get 10 different answers, and some of them will be delivered with real passion. Milk first or last? How long to brew? Teapot or teabag? Here is what the science says, and where it ends and personal taste begins.
What water temperature is best for tea?
Tea is mostly water, so the water matters. Use freshly drawn cold water and boil it once; Dr Andrew Stapley, the chemical engineer behind the Royal Society of Chemistry’s famous tea guide, recommends not reboiling it, as his Loughborough University guide notes. If you live somewhere with very hard water, a filter can help; the minerals in hard water can leave a dull film, or scum, on top of the tea. The temperature depends on the tea. Black tea, the everyday kind most Australians drink, brews best with water at or just off the boil. Green and white teas are more delicate, and water that is too hot makes them bitter, so let the kettle cool for a few minutes, to somewhere around 70 to 80°C, or use a kettle with a temperature setting.
Loose leaf or teabag?
Loose-leaf tea generally gives a fuller flavour, because the leaves have room to unfurl and release their flavour as they steep. If you use teabags, roomier pyramid-shaped bags give the leaves more space than flat ones. Either way, the Royal Society of Chemistry’s guide suggests about one rounded teaspoon of leaf, or roughly 2 grams, per cup.
How long should you brew tea?
This is where taste takes over, but there is some chemistry to it. In its 2003 guide, the Royal Society of Chemistry recommended brewing black tea for three minutes. Leave it much longer and more tannins come out of the leaves; they give tea its colour and body, but too many make it bitter and astringent, that dry, furry feeling in your mouth. If you like your tea strong, use more tea rather than brewing for longer.
Milk first or milk last? The great debate
This argument is older than most of us. In 1946, the novelist George Orwell published an essay called “A Nice Cup of Tea” in London’s Evening Standard, setting out 11 rules he regarded as golden. One of them was to pour the tea in first and add the milk after, because that way you can judge exactly how much milk to add, whereas pouring tea onto milk makes it easy to add too much, as Wikipedia summarises.
In 2003, to mark Orwell’s 100th birthday, the Royal Society of Chemistry published its own guide, written by chemical engineer Dr Andrew Stapley of Loughborough University, and it came down firmly on the other side. Milk should go in first, Stapley argued, because milk proteins start to break down, or denature, at temperatures above about 75°C. Pour cold milk into hot tea and the first drops are briefly surrounded by very hot liquid, enough to damage some of their proteins and change the taste. Pour hot tea onto cold milk instead, and the milk warms more gently, as the RSC’s guide explains.
There is a catch, though. The RSC’s method assumes you brew your tea in a pot, then pour it onto the milk in the cup. If you make your tea the way most Australians do, with a teabag dunked straight in the mug, putting the milk in first cools the water and stops the tea brewing properly. So the practical answer is: with a teapot, milk first is the scientists’ choice; with a teabag in a mug, brew first, take the bag out, then add the milk.
The right temperature to drink it
According to the RSC guide, the ideal temperature for drinking tea is between 60 and 65°C: hot enough to enjoy, without scalding your mouth. Milk and sugar are optional, the guide notes, but both soften tea’s natural astringency, which is why so many people take one or both. And the cup matters a little too. A plain porcelain or glass cup will not add any flavours of its own, which is why tea lovers tend to prefer them to heavily stained mugs.
The perfect cup, in short
Use fresh water, boiling for black tea and cooler for green. Give the leaves room to move, use about a teaspoon per cup, and brew for around three minutes. If you use a pot, the chemists say milk first; if you use a teabag in a mug, add the milk after. Then let it cool to about 60°C and enjoy it. Beyond that, the perfect cup of tea is the one you like, whatever Orwell or the chemists say. And if you are more of a coffee person, my posts on why coffee makes you poop and whether an apple can wake you up better than coffee are for you.
Sources
- Royal Society of Chemistry: How to make a perfect cup of tea (2003, PDF copy)
- Loughborough University: Dr Andrew Stapley’s guide to the perfect brew
- The Orwell Foundation: A Nice Cup of Tea (1946)
- Wikipedia: A Nice Cup of Tea
- IrishCentral: Dr Andrew Stapley’s guide to the perfect cup of tea