Coffee and tea taste bitter to most people because of the caffeine. Of course, some like their coffee dark, but most people, including yours truly, can’t have a sip without at least a lump of sugar inside. Apparently, we’re on to something. Adding sugar to coffee or tea not only cuts the bitterness, but changes the chemistry of the drink at a fundamental level, according to Dr. Seishi Shimizu at University of York.

Previously, researchers thought the bitter taste suppression was due to the change of “water structure” induced by the additives. Using  statistical thermodynamics, however, Shimizu showed that instead of the change of water structure, the bitter taste suppression must be due to the binding of sugar with the caffeine. The elemental cause is the affinity between water and sugar molecules, which in effect make the caffeine molecules stick together.

“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,” said Shimizu who published his work in Food and Function.

Millions of people around the world love coffee, not to mention tea. Knowing more about how various additives like sugar or salt react with water is highly important for the food industry. In effect, we might one day find that perfect cup of coffee. I know, a puritan’s dream.

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