If you’re trying to be healthy, you might have considered dropping the caffeine from your coffee. But perhaps you’ve heard of other things that have got you worried about your cup of Joe.
One of those might be acid. But what do we mean by acid when it comes to coffee? And is decaf coffee acidic?
Read on as we demystify the confusing world of acidity in coffee.
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What do we mean by acid in coffee?
Let’s start with being clear about what we actually mean here.
If you’re in a laboratory with a piece of litmus paper, you know exactly what acid is. It’s a liquid that’s going to turn that paper pink. But is this really what people are mean when they talk about acid in coffee?
Well, it can be. Coffee contains a number of different organic acids. These include tartaric, citric, acetic and quinic acids.
Most acids in coffee belong to a group known as chlorogenic acids. These are believed to have some health benefits, including in relation to Type 2 diabetes and weight loss.
All of these different acids affect flavor. But how?
Acids and flavor
The flavor of different acids is determined by the way their ions activate neurons on your tongue. Those clever neurons send messages to your brain telling you what the substance you’re drinking tastes like. The content of those messages depends on the chemical makeup of the drink.
Different types of coffee have different mixtures of acids, and the roasting process changes that further. The high temperatures involved effectively burn off some acids, whilst increasing others.
You probably know that citric acid is in lemons and oranges. It can provide the same citrusy flavor in your coffee. And if phosphoric acid is present too, you’ll get a hint of grapefruit.
You’ll get more fruity flavors from malic acid. In this case, it’s more likely to be notes of peach, pear, apple or plum.
Tartaric acid can give a wine-like taste – which is hardly surprising, given that you’ll find it in wine. Too much, though, and your coffee will taste sour.
It’s a similar story with acetic acid. At lower concentrations, it can sharpen up the flavor. But too much and it becomes vinegar.
These properties of acids mean that people sometimes use “acidity” to describe the coffee flavor. It’s usually considered a good thing, often describing a bright, clean taste. This YouTube video explains more.
So why avoid acidic coffee?
With all this good news about acidity and flavor, you might wonder why anyone would want to avoid it. Well, unfortunately, acid has some disadvantages too.
One of those is that it can damage the enamel on your teeth. Coffee actually makes a two-pronged attack on your pearly whites.
First, the acid it contains demineralizes your teeth. That damage then makes them more susceptible to acid erosion in the future.
Secondly, coffee helps the bacteria in your mouth create even more acid. It’s a veritable acid party in there! And that’s bad news for your teeth.
But the biggest problem for some people comes when the acid in coffee hits their stomachs. There it can cause unpleasant and painful acid reflux. For some unfortunate souls, the problem is so bad that they’ve had to consider giving up coffee altogether.
The main culprit here is quinic acid. At lower doses, it can give the coffee a clean finish, but too much of it can upset your tum. It tends to be found in greater quantities in dark roasts, but also in coffee that’s gone stale. (And that includes the stuff you’ve kept on a hot plate all morning!)
So one easy way to cut your chances of acid reflux is to use lighter roasts. Make your coffee fresh when you’re ready for it too. As well as being kinder to your digestive system, it will taste far better.
Is decaf coffee any better?
We know that decaf can be healthier. After all, coffee contains caffeine, and we know that too much of that can be bad for you. But what about the acid content?
Unfortunately, it really isn’t easy to answer that question.
Coffee can cause large amounts of gastric acid to be secreted in your stomach, irritating the lining. A 1975 study found that decaffeinated coffee actually had a bigger effect on this than regular coffee.
However, when it comes to acid reflux, decaffeinated coffee is a better option. A 1994 study on 16 healthy volunteers compared levels of acid reflux after they had drunk tea, coffee, and water. There were higher levels of reflux amongst the coffee drinkers.
But when the regular coffee was replaced with decaf, reflux levels were much lower. So the answer is that it’s the caffeine that’s causing acid reflux – right?
Wrong. Because the researchers also reduced the caffeine levels of the tea and added caffeine to water. In both cases, there was no difference to the earlier results.
So clearly something else is going on. There’s some other difference between the regular and decaf coffee that’s responsible for decaf causing less acid reflux.
Other options to cut acid levels
If you’re worried about acid irritating your stomach but still want the coffee flavor, there is another option worth considering.
Cold brew is made by steeping coffee grounds in cold water for around 24 hours. The lower temperatures mean that some of the compounds in the beans won’t dissolve. The result is a smooth flavor and a far less acidic drink that won’t irritate your stomach.
As we’ve seen, people can mean lots of different things when they talk about coffee acidity. For some people it’s a positive attribute, denoting fruity flavors and a clean taste.
Move away from flavor though, and talk of acid becomes more problematic. Whether it’s damage to your tooth enamel, an irritated stomach lining or indigestion, acid can be to blame. And while switching to decaf can reduce the risk of acid reflux, it can actually increase gastric irritation.
If you’re looking for a low-acid coffee, your best bet is cold brew. And for a hot beverage on chilly days, opt for tea or cocoa instead.