Coffee Acidity and Processing

July 26, 2009 – Of all agricultural products coffee, is perhaps one of the
most complex, far more complex than wine and tea combined. But how we process
the coffee – during cultivation, roasting, and brewing – can significantly
affect the overall flavor of coffee. Read more below…

Some people aren’t able to drink coffee because it bothers their stomach, but
is it really the acid? In terms of the pH profile, coffee rates as low-acid,
coming in at 4.5 – 6.0, depending on the coffee (A pH of 7.0 is neutral). Most
regular sodas, diet sodas, orange juice and lemonade are significantly more
acidic, at 2.0 – 3.0 pH.

Coffee has a multitude of chemical constituents; it’s more complex than wine.
It is possible that the acids (of which there are many) are the culprit, but
coffee does contain other components that are potentially irritating to the
human gut. Despite all the research that’s been done, there is still much that
is unknown about how the different elements in coffee react in our bodies.

Acidity in coffee is not related to its pH level, and is actually considered
to be a desirable quality. Acidity refers to the flavor profile, similar to the
sensations you experience when drinking wine: the tartness, brightness, zing or
various regional influences in the bean, that hit both your tongue and your
palate when you take a sip.

The acidity of a coffee is partly due to the growing region and partly
influenced by the way a bean is processed and roasted. Coffee grown at higher
altitudes and in volcanic soils tends to be higher in acidity, and is generally
more highly prized. Brazilian, Peruvian, Kenyan and Ethiopian beans falls into
this category. The coffees that are lower in acidity, such as Sumatra, are grown
at lower elevations.

The roasting process is also very influential. The darker the roast, the
lower the level of acid. An Espresso or French roast will be lower in acidity
than an American or Viennese roast, for instance. A lower acid (dark) roast will
also be “flatter”; remember, in coffee, acidity = greater flavor mosaic.
Incidentally, the darker roasts, despite tasting stronger, also have a lower
caffeine content.

Finally, the brewing method comes into play, too. Cold brewing your coffee is
one way to dramatically reduce the acidity of your coffee.

So if it is the acids, or perhaps the caffeine, in coffee that are the
tummy-torturers for you, there is hope. It could be that switching to a dark
roast and/or cold brewing your coffee at home is just the ticket.

Watch for an article coming soon on cold brewing.

Source: Examiner.com

http://coffeechemistry.com/index.php/News/Chemistry/Science/coffee-acidity-and-processing.html