Thoughts on Acidity in Coffee

9 comments

• By Brent  |  Thursday, August 6, 2009 10:16 AM

  I still have this acidity topic on my mind. Mainly because I wonder if some of us lay people may perhaps misunderstand acidity as it relates to coffee. I fully agree with you Poul that the acidity in coffee has little to do with how coffee may, or may not affect our stomachs.
  
  I found a very good definition and description of acidity as it relates to coffee. Rather wordy, but detailed. I found it very informative and helpful, so I thought others may find it as informative as I did. I hope you guys don't mind if I post it here and I hope Tom Owen doesn't mind.
  
  ACIDITY
  Acidity in arabica coffees is almost always considered a positive flavor
  attribute, yet the term can sound unattractive. People may relate acidity to stomach discomfort, or to sour flavors. This would be incorrect. The acidity in good high-grown arabicas imbues the cup with delicate flavor accents, complexity, and dimension. Good acidity is fleetingly volatile, a momentary sensation, giving effervescence to the
  cup, and informing the mouthfeel as well. Coffees with no acidity can taste flat. Acidity is not about quantity, it is about quality, and good
  coffees have a complex balance of many types of acidity: malic, citric, acetic, phosphoric, quinic, to name a few ... and a whole set of
  chlorogenic acids that are very important to flavor experience as well. Kenyas, which by flavor are some of the higher acid coffees, actually have measurably less than Brazil arabicas (of quinic and citric acids),
  more of others (malic, phosphoric) and far less than some robusta coffees (chlorgenic acids)! Dark roasts tend to flatten out acidity in
  flavor. But contrary to the taste, darker roasts have more acidity than lighter roasts. (This surprised me)
  So quantity does not always follow perception. Acidity in coffee might be described by terms like bright, clear, effervescent, snappy, dry, clean, winey, etc. Coffees without acidity tend to taste flat and dull, like flat soda. Acidity is to coffee what dryness is to wine, in a sense. Different coffee origins will possess different kinds of acidity; like the wine-like high notes of some African coffees versus the crisp clear notes of high grown coffees from the Americas.
  Unpleasant acidy flavors may register as sourness.

  
  
• By Poul Mark  |  Tuesday, August 4, 2009 08:31 PM

  It is true, coffee is not very acidic in comparison to other drinks. We are definitely referring to the acidic flavour aspect in coffee. I think many people complain about bitterness, but mislabel it as acidic. I honestly don't think acid is the culprit in coffee.

  
  
• By Brent  |  Tuesday, August 4, 2009 06:52 PM

  a quick afterthought, if I remember correctly, not only Coke, but many fruit juices have much more acid in them than coffee which really isn't that acidic.
  Isn't it true that when one refers to the acidity in coffee they are actually referring to a flavor attribute of the coffee (IE the brightness) rather than an actual level of acid in the coffee?

  
  
• By Stewart  |  Sunday, August 2, 2009 01:26 AM

  I hope you don't use cute little hamsters in your experiments.

  
  
• By Stewart  |  Sunday, August 2, 2009 01:24 AM

  Poul, I think you are right.
  
  From Prostaglandins, Leukotrienes and Essential Fatty Acids
  Volume 68, Issue 4, April 2003, Pages 257-261:
  "It is concluded that lipid peroxidation is a mechanism involved in the pathogenesis of gastritis associated or not to H. pylori infection."
  
  From Wikipedia:
  "Lipid peroxidation refers to the oxidative degradation of lipids. It is the process whereby free radicals "steal" electrons from the lipids in cell membranes, resulting in cell damage. This process proceeds by a free radical chain reaction mechanism. It most often affects polyunsaturated fatty acids, because they contain multiple double bonds in between which lie methylene -CH2- groups that possess especially reactive hydrogens. As with any radical reaction the reaction consists of three major steps: initiation, propagation and termination."

  
  
• By Brent  |  Thursday, July 30, 2009 02:48 PM

  I tend to lean to the caffeine itself causing the stomach upset. As many of us know, Arabica beans have 1/2 the caffeine as robusta beans which many people may have drank before they switched to better coffees. (I wonder if T-Hortons coffee is Arabica?) It just seems that some stimulants (nicotine for one, ADHD meds list stomach upset as a side effect) cause the stomach to produce more stomach acids according to what my doc told me. I have a few reasons for believing it's the caffeine itself.
  
  I too have had problems with GERD off and on over the years. (That lovely burning throat senssation) After going on meds it was better but, wouldn't get competely better. For me, smoking cigarettes (I've now quit but still smoke a cigar a few times a week) with coffee bothered my stomach and GERD, especially after more than two coffees. My doctor told me as long as I smoked, my stomach wouldn't heal properly. He said the stimulant properties in nicotine irritate the stomach; mostly by causing it to excrete excess acid. Lo and behold, when I finally did quit, I had a lot fewer stomach problems. Now I can drink two large caffeinated 16 ounce mugs in the morning with little problem, but more than that in a row and my stomach will start acting up. I've also noticed when I make decaf iced coffee, (iced espresso,milk and some sugar... on a hot day I'll sometimes have 3 in a row) even after a number of them, it doesn't bother my stomach at all. I believe it's the decaf making the difference for me, not the milk coating the stomach as too much milk actually bothers my stomach, and I don't use much milk in my frappes.
  That's my two cents
  Has anyone else noticed decaf is easier on their stomachs?

  
  
• By Jan Goh  |  Tuesday, July 28, 2009 06:38 PM

  I've never had a problem with your coffee, no matter how much I've had.
  
  On my drive from Edmonton to Montreal, though, I grabbed a double-double from Tim Horton's, and 20 minutes later I was hunting for a road-side stop. Doesn't happen everywhere (or even at every Tim Horton's).

  
  
• By Rich W  |  Tuesday, July 28, 2009 12:10 PM

  We brew and drink fresh Intelli here. I've had GERD for years. Any caffeinated beverage consumed in copious quantities will make me miserable, but especially coffee and tea. Had to give up competition judging because of that. And cupping a number of coffees at once is a bitch. So, if you ask me, it's not the roast level. At least not for folks like me.

  
  
• By Jody Carlson  |  Tuesday, July 28, 2009 10:58 AM

  I've also had people claim my coffee wasn't as upsetting to the stomach. I wonder if it has to do with the quality and the fact that most of it is organic, pesitcide free coffee that has had care taken in it's sorting and preparation. That will be really cool when you guys start getting results from the lab.