How many sugars in your tea? – The effect of sugar on water structure and taste.

New research published in the University of York shows that sugar has a significant effect in reducing the bitterness of tea and coffee, particularly by manipulating the essential chemistry.

Sugar has a strong way of affecting chemical “water structure” and this enables it to suppress the bitter taste of tea. The researchers also look into how sugar is able to change the structure of caffeine – when it has additives and without additives.

The research, published in Food and Function journal, reveals new insights into how caffeine, sugar and water interact at a molecular level to alter the taste of hot beverages.

Caffeine is widely available in tea and coffee, when in water, caffeine molecules tend to conjoin together and this effect is increased when sugar is also added. Old scientific theories suggested that this was due to the strengthening of bonds between the water molecules around sugar.

However Dr Shimizu’s team found that the actual cause of this phenomenon is actually due to the high affinity between sugar molecules and water, which in turn causes the caffeine molecules to conjoin in order to avoid the sugar. This is the exact reason why we don’t experience tea and coffees bitter taste.

The scientists used a branch of theoretical physical chemistry called statistical thermodynamics to investigate the molecular level activities and interactions behind our daily food and drink.

Dr Shimizu says: "It is delightful indeed that food and drink questions can be solved using theory, with equipment no more complex than a pen and paper.  Encouraged by this discovery, and our recent success on how to make jelly firmer, we are working hard to reveal more about the molecular basis of food and cooking."