[Video Guide] Understanding Acidity in Coffee: What It Means and How to Choose the Right Roast for You

Did you know there’s acid in your coffee? Don’t panic — it’s not a bad thing. Acidity is what gives coffee its lively, fruity brightness and complex flavor. But if you’re prone to stomach sensitivity, or simply curious about how roast level and brewing methods affect acidity, understanding the science behind it can help you make the perfect cup for your taste — and your digestion.

Frequently Asked Questions

Is acidity bad in coffee?
No — acidity contributes to the bright, fruity flavors coffee lovers enjoy. It’s only problematic for those with acid sensitivity.

Which roast is lowest in acid?
Dark roasts like Sumatra Mandheling or Brazilian coffees have naturally lower acidity.

Does cold brew really have less acid?
Yes — cold brew is typically 60–70% less acidic than hot coffee.

Can brewing fix sour coffee?
Yes. Grind finer or extend your brew time slightly to reduce sourness caused by under-extraction.

Yes, there’s acid in your coffee — and that’s a good thing. Coffee naturally contains more than 1,000 chemical compounds, including several organic acids such as chlorogenic, citric, malic, and lactic acids. These compounds are what give your coffee its tang, sparkle, and fruit-like character.

But for people who are acid-sensitive or have gastric issues, that same acidity can sometimes cause discomfort. The good news? You can manage acidity by understanding what affects it — from roast level to brewing method to grind size.

The Role of Roast Level

Roast level plays the biggest role in coffee’s acidity. As coffee beans roast, their natural acids begin to break down. Here’s how that works:

• Light Roast: Light brown beans with no oil on the surface. They retain the most natural acids and caffeine, resulting in the highest acidity. Light roasts can be up to 10 times more acidic than dark roasts and often have bright, citrusy or fruity notes.

• Medium Roast: Medium brown color with a balanced profile. These beans maintain some acidity but offer a smoother, rounder taste — often described as caramel, nutty, or chocolatey.

• Dark Roast: Dark brown, often oily beans with the least acidity. The longer roast time breaks down chlorogenic acids, producing a low-acid, bold flavor with hints of cocoa or smoke.

If you’re seeking low-acid coffee, choose Sumatran, Brazilian, Nicaraguan, or Peruvian varieties roasted to around 435°F or higher. These beans typically brew at a pH of about 5.2 or above, making them gentler on the stomach.

Brewing and Extraction Matter

Acidity isn’t just about the beans — it’s also shaped by how you brew. The moment hot water hits your grounds, it begins extracting compounds that define flavor and aroma.

Here’s how extraction affects acidity:

• Short brew time or coarse grind: Leads to under-extraction and a sour, grassy taste.

• Longer brew time or finer grind: Creates over-extraction, resulting in bitterness.

• Water temperature: Hotter water extracts more acids; cooler water can leave the coffee flat.

If your coffee tastes sour, try grinding slightly finer and extending your brew time.

Ranking Brew Methods by Acidity

From most to least acidic:

1. French Press – Uses coarse grounds and short contact time, resulting in higher acidity.

2. Drip or Pour-Over – Medium grind, moderate brew time, and balanced acidity.

3. Espresso Machine – Brews quickly under high pressure; low-acid if using dark roast beans.

4. Cold Brew – The least acidic brewing method. Because cold water never releases coffee oils, cold brew can be up to 70% less acidic than hot coffee.

Final Takeaway

If your coffee tastes sharp or upsets your stomach, don’t give it up — just adjust your recipe.

• Use darker roasts for lower acidity.

• Try cold brew or espresso over French press.

• Always grind fresh and experiment with brew time and temperature.

With a few tweaks, you can enjoy a smooth, flavorful cup that’s perfectly suited to your taste and your body.

Full Video Transcript:

"Wait — there’s acid in coffee? Absolutely. If you weren’t aware, coffee is acidic. There are over 1,000 chemical compounds in coffee, making it one of the world’s most complex drinks. This usually isn’t regarded as a bad thing, because when it comes to taste, the acidity is what gives coffee the fruity, lively flavor that many coffee lovers enjoy.

The acids in coffee range from chlorogenic to citric, and even lactic and malic acids. It’s not always straightforward which coffee will be low-acid or have a higher pH. Today, we’ll talk about how to identify the differences between darker, medium, and light roasted coffees, and how those differences affect acidity after the roasting process — as well as which brewing methods can help.

So why would you need low-acid coffee? If you’re suffering from some form of gastric problem, one of the causes could be acid sensitivity, meaning that the tissue lining the stomach and duodenum may be overly sensitive to normal acid levels and easily irritated. If you are acid-sensitive, you’ll want to seek out less acidic coffees — and there are certain types of coffee that are naturally lower in acid.

Coffees can be categorized into three main types of roasts: light, medium, and dark. Light roast coffee can be described as light brown in color and has no oil on the surface of the beans. This type of roast contains the most caffeine, which contributes to a lower pH and, in turn, higher acidity. Did you know that light roast coffee is up to ten times more acidic than a dark roast?

Medium roast is a slightly darker brown color and also does not have oil on the surface of the beans. It tends to have a mid-range pH level and a more balanced flavor profile.

Dark roast coffee can be described as dark brown, even close to black, and is characterized by drawn-out oils that glisten on the surface. It contains the least amount of caffeine, which contributes to a higher pH and lower acidity.

The most common beans you’ll find in low-acid coffees include Sumatran, Peruvian, Brazilian, or Nicaraguan varieties — or blends of these — roasted to around 435°F or higher. These typically produce a brew with a pH around 5.2 or greater. While there are exceptions, such as a City Plus roast of Colombian Peaberry with a pH of 5.2, a dark-roasted Indonesian coffee like our Sulawesi Reserve or Sumatra Reserve will consistently produce a lower-acid cup.

Roasting coffee longer decomposes more of the chlorogenic acids that give lighter roasts their brightness. Most coffee varieties are naturally acidic, with an average pH value of 4.85 to 5.10. Among the countless compounds in coffee, the brewing process releases nine major acids that contribute to its flavor profile. The geographical location where coffee is grown also affects acidity, since altitude directly impacts pH levels.

Contrary to popular belief, many stomach issues caused by coffee can be reduced simply by eating breakfast before drinking it.

Acidity in coffee is also directly linked to how it’s brewed. Under-extracted coffee tends to be more acidic. This can happen if the grind is too coarse or if the coffee isn’t brewed long enough.

Extraction begins the moment hot water makes contact with the grounds — that’s when flavor and aroma compounds start diffusing into the water. The finer the grind, the more quickly extraction happens; a coarse grind results in higher acidity, while a finer grind leads to more bitterness. The longer the brew time, the more extraction takes place. Short brews are more acidic, while longer ones tend to be more bitter.

Water temperature plays a big role, too. The hotter the water, the faster extraction occurs. If the water is too cool, the acids won’t fully extract, affecting flavor both positively and negatively.

A key characteristic of under-extracted, overly acidic coffee is a sour, grassy taste rather than a smooth, whiskey-like finish. The good news is this is one of the easiest problems to fix — it usually just requires adjusting the grind size or the brew time.

Here’s how common brewing methods compare in terms of acidity. French press brewing, which uses a coarse grind and short steeping time, typically produces the most acidic coffee. Drip coffee makers or pour-over methods use medium to medium-coarse grinds and result in moderate acidity levels, since the brew time is generally under 10–15 minutes.

Espresso machines brew coffee quickly under pressure and tend to produce low-acid results, especially when using darker roasts. Cold brew, however, stands out as one of the least acidic brewing methods overall. Because cold water never releases the oils in the beans, cold-brewed coffee can be up to 70% less acidic than traditional hot coffee.

So, to summarize: for a more acidic cup, aim for a higher water temperature, coarser grind, and shorter brew time. If your coffee tastes sour, grind finer and brew longer. And if you want to avoid acidity altogether, go for a dark roast and use the cold brew method — just remember to let it steep longer, since extraction takes more time at lower temperatures."