We received this information from one of our good customers, who has become a home roaster and does very well at home roasting as we have cupped some of his roast profiles and we had better watch out for our jobs. Thx to CDR BIll
We have had many conversations with fellow coffee roasters and those who just enjoy a dark roasted cup of coffee or a smooth espresso without the bitter aftertaste. We have told many it is our roast profile, as we know when to drop the beans from the roaster, how much time to leave them in the open air, when to heat seal them and how long it takes for the beans to naturally develop into a smooth French Roast without a bitter taste. Luck - Art - Science? Perhaps a little of all, but it works for our Espresso Blends and our Deep Blue French Roast.
Jeanna Bryner
LiveScience Staff Writer
LiveScience.com Tue Aug 21, 2:00 PM ET
Chemists have figured out why dark-roasted coffees are so bitter, a finding that could lead to a smoother cup of java.
Using chemical analyses and follow-up taste tests by humans trained to detect coffee bitterness, the scientists discovered the compounds that make coffee bitter and also how they form.
"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 percent of coffee's bitter taste comes from caffeine, said Hofmann, who presented his findings today at a meeting of the American Chemical Society in Boston.
Hofmann and his colleagues found two classes of compounds give coffee the bulk of its bitterness. Both pungent perpetrators are antioxidants found in roasted coffee beans, not in the green (raw) beans.
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, Hofmann said.
"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 added that prolonged roasting leads to the formation of the most intense bitter compounds found in dark roasts.
How the beans are brewed also affects bitterness, the scientists found. 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.
View this Article online
http://news.yahoo.com/s/livescience/20070821/sc_livescience/chemistsfindwhatmakescoffeebitter?a
http://islandjoesgourmetcoffee.com/no_bitter_coffee.asp
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