Coffee gives up its bitter secret
26 Sep 2007 by Evoluted New Media
It may be vital for that early morning pick-up, but scientists now think that caffeine is not responsible for your coffee’s bitter taste.
It may be vital for that early morning pick-up, but scientists now think that caffeine is not responsible for your coffee’s bitter taste.
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| It may wake you up – but caffeine wont leave a bitter taste |
“Everybody thinks that caffeine is the main bitter compound in coffee, but that's definitely not the case,” said study leader Thomas Hofmann, a professor of food chemistry and molecular sensory science at the Technical University of Munich in Germany.
Just 15% of coffee’s bitter taste comes from caffeine, said Hofmann, who presented his findings at a meeting of the American Chemical Society in Boston.
He found that two classes of antioxidant compounds gave your early morning cuppa that tell-tale bitter taste. One class, called chlorogenic acid lactones, is present at high levels in light- to medium-roast brews. Dark roasts, such as espresso, showed high levels of phenylindanes, which form when the chlorogenic acid lactones break down and give a more lingering, harsh taste than their precursors.
“Roasting is the key factor driving bitter taste in coffee beans. So the stronger you roast the coffee, the more harsh it tends to get,” Hofmann said.
He also found that how the beans are brewed also affects bitterness. The high pressures and temperatures used for brewing espresso-type coffees produce the highest levels of bitter compounds.
“Now that we’ve clarified how the bitter compounds are formed, we're trying to find ways to reduce them,” Hofmann said.
