Coffee is arguably the world's most exotic non-alcoholic beverage. Its history is timeless, and one may say, it's here to stay.
Yet, coffee lovers get curious over the oft talked-about “acidity” in their beloved beverage. More than that, they consider how much impact this may have on their health.
This article aims to unravel what acidity means in the context of coffee, its impact on various health conditions, and the various ways to improve or lower this acidity.
The word may elicit words such as “sour,” “sharp,” “tart,” “tangy,” or even “bitter.” But, acidity is a chemical characteristic of some substances. You measure acidity using a pH scale. The scale measures how much acid or base is present in an aqueous (water-based) solution.
The pH scale is rather concise when compared to others. It begins at 0 and ends at 14. So, how does this work? Any solution sitting anywhere between 0 to 7 on the scale is acidic. On the other hand, basic solutions score any value between 7 and 14.
One simple way you can test for acidity is to use a strip of Litmus paper (now you know where the phrase “litmus test” comes from). Litmus paper comes in two varieties: blue and red. Acids or acidic solutions turn blue litmus paper red, while bases or basic solutions turn red litmus paper blue.
Acidity in Coffee
Coffee varieties are mostly acidic. The average pH sits in the range of 4.85 to 5.10. Nine major acid compounds define the unique flavor profile of your coffee. In terms of their relative concentration, these are the compounds from the highest to the lowest:
- Chlorogenic acid
- Quinic acid
- Citric acid
- Acetic acid
- Lactic acid
- Malic acid
- Phosphoric acid
- Linoleic acid
- Palmitic acid
The brewing process releases these nine acids from coffee beans to achieve the acidity range defined above.
Veteran coffee drinkers use a more qualitative definition for coffee acidity. They refer to it as the sparkling, dry, and bright sensation of coffee. It’s a distinctive factor for coffee varieties, separating high-quality, high-grown breeds from lower-grown ones. Note that while many premium varieties of coffee come from high-elevation plantations, and have bright qualities, it’s not completely objective to view coffee and coffee acidity this way.
Other less-nerdy coffee drinkers consider acidity as the quality of coffee that causes their tummy to hurt. This sickening, astringent quality makes it hard for them to enjoy their otherwise exciting brew truly.
Back to the science-y approach, 7.0 on the pH scale indicates neutrality, and a higher-acid breakfast coffee blend is more likely to have a pH of 4.7. On average, "black coffee" has a pH of just under 5.0.
Crucial Factors that Influence Acidity in Coffee
Various variables determine coffee acidity. We'll explore those in this section. These are the main contributing factors to coffee acidity:
- Roasting technique
- Brewing method
- Ground size
How do you roast your coffee beans? This factor is a principal in determining the final acidity of coffee. There is strong empirical evidence that the duration of roasting and temperature correlate strongly with acidity.
According to one study, roasting the coffee beans longer and hotter lowers the level of chlorogenic acid. Therefore, the lighter roasts tend to have a higher acidity, whereas darker roasts are less so.
Did you think your brewing method mattered so much? Again, cold-brewed coffee is significantly lower in acidity than hot coffee.
How long should you spend brewing your beans? Perhaps the answer lies in knowing that a shorter duration results in a more acidic coffee, while a moderate duration results in the extraction of less acid from the coffee.
Acidity is also a function of the size of coffee grounds. Smaller grounds expose the more of the coffee area relative to volume. As such, it's easier to extract more acid in the brewing process, yielding more acidic coffee with a finer grind.
Health Implications of Coffee Acidity
Coffee acidity is a quality that most people have no problems with. But, it worsens certain health conditions in others.
High-risk conditions include irritable bowel syndrome (IBS), acid reflux, and acid reflux. Two factors – coffee acidity and its mild laxative effects in certain people – are responsible for the impact of coffee on these conditions.
A simple way to avoid these complications is to consume less acidic coffee varieties. An increasing number of coffee drinkers now prefer these “low-acid” options. Doctor recommendation and a sick feeling in their tummy after drinking coffee are common reasons for this. pH levels don’t necessarily correspond to an individual’s experience of a particular coffee. So, how may one identify a low-acid coffee?
How to Reduce Coffee Acidity
Having established that acidity in coffee may have grave consequences for some, we must note that all it doesn't mean the can no longer enjoy the intensely pleasurable essence of their premium cuppa.
These are five ways to reduce acidity in coffee:
- Consume dark roasts instead of light.
Note that this may also mask origin profiles. It makes it necessary to consider the original qualities of the green beans before roasting them beyond recognition.
Some robust coffee breeds with dark chocolatey and earthy qualities can endure a darker roast while retaining their burly flavor. The roast qualities bury the more delicate berry, citrus, and herbal notes.
- Go for cold brew instead of hot.
Cold-brewing extracts a minimum of acids and everything else from coffee. Cold brewing results in a sweet smooth coffee, which coffee enthusiasts prefer during the warm summer months. There are cold brew systems available from your favorite online or offline retailer.
You can enjoy a milk-based espresso drink such as a latte or cappuccino if you want to enjoy coffee and appease your stomach from having uncomfortable irritations.
- Increase brew time by using a French press, for example.
- Coarse grinds are better, as they generally release less acid during brewing.
- Keep the temperature low during brewing.
The Coffee Review’s Kenneth Davids contends that treating coffee beans or using antacids (from “anti-acid”) in your coffee blend or dark-roasting them is less effective than beginning with a lower grown coffee with non-artificial low acidity. You can then carefully pick and process the beans to a moderate roast that develops the sugars without burning them.
So, the ultimate formula seems to be never to include any non-natural elements in your coffee, while relying on naturally lower-acid green bean and roasting to a medium-to-dark roast level to complement its origin.
On the other hand, add cold water to ground coffee, and allow it for no less than 12 hours. Use the concentrate to make low-acid coffee.
Now for some important side note. We’ve earlier said that pH does not always translate to one’s physical experience of a coffee. However, some tasters appear to possess a heightened perception of acidity, referring to how bright or tangy the brew is on the palate. They can trust their sense of tracking actual pH levels of the coffees. Therefore, to find a viable low-acid coffee option for you, trust your senses and boldly explore a few varieties. Your experience is enough to help you make a choice.
Dexter Makes Better Coffee
Remember Dexter, the young nerdy cartoon character? You can follow his lead and create your perfect cup of java. This series of experiments will see you neutralize the coffee acid using a base (which is alkaline). The base's job is to calm your coffee until your mixer is just as tart as you want it to be.
Milk is slightly acidic – on the left side of the pH scale neutral – thus, it's not the optimal neutralizer you want.
Now, it’s time to heat up the pantry with a sprinkling of baking soda (chemical name, sodium bicarbonate) in your cup to douse the acidity in your coffee. Sodium bicarbonate has zero flavor and is a key ingredient in many antacids.
Oh! If baking soda doesn't catch your fancy, try almond milk. Almonds are alkaline by nature and can help eliminate any acidity in your coffee. Almond milk is nothing like acid alternatives such as cow's milk and other nut- and legume-based milk products. Plus, it's a mere 45 calories per cup, an enticing fact if your love handles are stealing the spotlight too soon.
Coffee, Your Body, and Acid
You should concern yourself with more than acidity in coffee. When your body digests anything, it has to secrete acid. The roast of your coffee has some significant influence on the quantity of stomach acid you produce. Volunteers in a February 2014 study published about in Molecular Nutrition & Food Research showed that those who drank a dark roast blend experienced lower levels of gastric acid secretion. By contrast, those who drank a medium roast secreted more gastric acid.
In other words, the darker the roast, the lower the acid profile. That really should define how you fish out the coffee that matches your palate.