Coffee Acid: Friend or Foe?

Coffee Acid: Friend or Foe?
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I see many customers come into the café requesting a coffee with low acidity. It is clear that coffee acid can upset people’s stomachs, producing symptoms like acid reflux. For years we have recommended our Kona, with its perceptibly smooth lack of acidity to people who are sensitive to acid in coffee.   That can’t be the only option though, right? I decided to tackle the research out there on coffee acidity to see if there is anything more we can suggest when people ask that age-old question.  How can I enjoy coffee without consuming so much acid?

Coffee acids: taste and other benefits

Acid in coffee lends some great flavors.The Flavor Wheel provided by the SCAA.

The intricate flavors that we enjoy in coffee come from a mixture of volatile coffee acids, oils, and other coffee solids. Our KetoTapasi Papua New Guinea beans, for example, offer a delicate citrusy sweetness. We can thank some citric acid for those lemon notes. It is the balance of flavor-producing compounds that makes coffee delicious and many of those compounds are acids. When we brew pourovers, we time and pulse our pours specifically to control how we extract acids from our ground beans.  The acids we extract give coffees unique brightness.  Most of coffee’s flavor-produciong acids are probably not the ones that are giving coffee drinkers a problem.

When discussing coffee acid, it seems important to take a close look at chlorogenic acids.  I keep seeing this group of acids pop up in coffee literature, in both a positive and negative light.  On the bright side, Emma Sage, Coffee Scientist for the SCAA, writes about some of their benefits.  In her article, Coffee Roasting Chemistry: Chlorogenic Acids,  she writes that chlorogenic acids are actually the most abundant of the acids in coffee.  They are part of a group of acids that are found in many plant’s defense systems against harmful insects.   Sage notes that, chlorogenic acids have gained press for their antioxidant qualities.  From this angle, they look pretty good to keep around.

 Here’s the trouble with coffee acid:

Coffee tends to fall right around a 5 on the pH scale. That is comparable to peanuts or white bread.  Drinks like beer, orange juice, and tomato juice are all higher in acidity than coffee. Why does coffee acid have such a noticeable effect on some people’s stomachs? It may have to do with the ways some of the compounds in coffee interact with our own bodies’ chemistries.

Chlorogenic acid, our famous antioxidant, may also be responsible for the stomach upset people sometimes feel when drinking coffee. According Livestrong’s article Can Coffee Damage the Lining of your Stomach this acid stimulates our stomach to produce more of our own gastric acid, which is designed to aid in digestion.  Gastric acid may be what is making some people feel sensitive to coffee. Caffeine also urges our stomach to make more gastric acid (yikes, we need the caffeine).

But wait! There is some hope.  According to Whole Latte Love,  coffee also contains a compound called N-methylpyridinium (N-MP), which appears to counteract some of our stomach’s acid production . Mother Nature came through for us on that one.  So if you are sensitive to coffee, what you need to do is prepare it in a way that will select for N-MP, and keep as little chlorogenic acid around as possible.

 How can we reduce certain coffee acids?

How can we choose which coffee acids stay in our cup?  Well, first of all, let’s look at the beans. According to Coffee Review, beans from Sumatra and Brazil tend to be relatively low in acid.

Dark roasts: lower in chlorogenic acidDarker coffees may contain less stomach-irritating coffee acid.

In order to drink less acid with your coffee, you may also want to pay attention to roast level.  Monica Reinagel, in her Nutrition Diva podcast explains that chlorogenic acid levels decrease during roasting, while N-MP levels increase.  This means that the darker the roast you are drinking, the less acid will be produced by your stomach. That does not necessarily mean that dark coffees taste smoother.  When chlorogenic acid breaks down, it produces bitter compounds. Depending on you preferences, this may not be want you want in your cup. Personally, I enjoy our medium roast Oromia Coop Ethiopian beans right now, and they are pretty light and sweet.

Monica Reinagel also points out that the fat in milk helps to bind chlorogenic acid so that it does not affect our stomachs as much. Milk in your coffee will probably not bind all of the chlorogenic acid, but it could help reduce its impact. This suggests that if you are sensitive to acid in coffee, you may benefit from drinking whole milk or cream in your latte or coffee, instead of low fat milk or no milk at all.

Cold brew techniques, like Toddy,  have gotten some buzz for reducing coffee acids in a brewed cup.  This method, however, is not known for producing the most aromatic cup.  Also, chlorogenic acids break down in the presence of heat, so while you may be extracting less overall chlorogenic acid with a cold brew method, what’s left there may be left more intact. Basically, there seems to be evidence to support cold brew coffee being lower in acid overall, but I am not sure how this technique affects the ratio of chlorogenic acid to other acids in the coffee.

So what if you just love a lightly roasted coffee with bright notes, brewed in a Chemex or a Kalita Wave, but you are trying to avoid acid? Well, as long as it is not actually a health concern for you, I’d say treat coffee like a delicate, cherished part of your morning routine.  Savor a small amount of that sweet, slightly acidic goodness, without drinking so much that your stomach reciprocates.  If you like lattes, let us make you whole milk cortado. If you’re still in the mood for some hot morning brew after your small coffee hit, you can dive into our diverse selection of herbal teas!


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