When coffee beverages are prepared by other methods (for example, drip filters or plungers), ground coffee beans are simply combined in one way or another with hot water to release flavor, aroma and body. The espresso method (known as extraction) uses hot water and pressure. This is how it is prepared.
Hot water under pressure has the capacity to extract more from coffee beans than hot water alone. The aim during extraction is to get the “best of the bean” into the beverage.
By the “best” we mean the substances in coffee beans that give espresso beverages maximum flavor, aroma and body.
When this process has been successful and ideal extraction has been achieved, the result is always the same: the perfect espresso.
But sometimes the results can be different. There are 3 extraction variations:
Ideal extraction:This extraction causes the maximum potential in flavor aroma and body to be released from ground coffee beans. The resulting beverage is full-bodied with a well-balanced flavor, a good aroma and no undesirable bitterness or aftertaste.
Under-extraction:At this point, the maximum potential of the coffee beans has not been released. The resulting beverage is generally thin-bodied with an under-developed flavor and aroma. Usually it has a sour, watery taste.
Here, the maximum potential of flavor, aroma and body has been released from the ground coffee beans. But this is not all. Other unwanted bitter substances are also released. The resulting beverage has an undesirable aroma and an over-developed, burnt, bitter flavor.
Now that you know more about this beverage, let us know your opinion!
Source: Barista Bible.