A storm in a tea cup?
clash over the perfect cuppa. Is it physics, or chemistry?
A storm is brewing over the UK's national beverage as scientists clash over the perfect cuppa. Is it physics, or chemistry?
Elaborate findings on how to make the finest cup of tea were released this week by the Royal Society of Chemistry. They include advice such as, 'use freshly drawn water, previously boiled water will have lost some of its dissolved oxygen, important to bring out the flavour' and, 'tea bags are a handy convenience, but they do slow down infusion, and favour infusion of the slower infusing but less desirable higher molecular weight tannins.' But according to the UK Institute of Physics, the advice does not hold water.
"Trust chemists to make things complicated,"said Dr Julia King, chief executive of the Institute of Physics. "The RSC are making matters difficult - as the main point is to keep the water temperature at 98 degrees. Materials physics holds the answers."
And the key to keeping the temperature? It all comes down to porcelain. "Porcelain can withstand higher thermal shocks - you can pour hotter liquid into a cold cup - than cheaper china." Moving onto the old 'milk before tea, or vice-versa' debate, for the physicists putting the milk in first has nothing to do with taste.
"It is a habit we have retained from the times when only the rich could afford porcelain," added Dr King. "Which, because it isn't as porous as china, could withstand the hot tea being poured in directly. Those of us with cheap china had to put the milk in first to cool the tea slightly to prevent our cups from cracking." As simple as that. Stirring the debate further, Dr King concluded: "So in this case our taste has been moulded by the physics rather than the chemistry."
