Which Type of Roast is Less Acidic?

November 14, 2025 •

4 min read

According to the National Coffee Association, coffee is mildly acidic, with a typical pH range of 4.85 to 5.13. If you want to reduce acidity, a darker roast is the best choice, as the longer roasting process breaks down the acidic compounds in the bean.

Quick Summary

Dark roast coffee is the least acidic roast level due to the extended roasting time and higher temperatures that break down acidic compounds. Other factors like bean type (Robusta vs. Arabica) and brewing methods like cold brew also significantly impact coffee's acidity.

Key Points

Dark Roast is Less Acidic: The longer, hotter roasting process of dark roasts breaks down acidic compounds, resulting in a lower acidity than light or medium roasts.
Cold Brew is Significantly Lower in Acidity: Brewing with cold water over a longer period extracts fewer acidic compounds, making it a much gentler option for sensitive stomachs.
Robusta Beans are Naturally Lower in Acid: Choosing Robusta beans instead of Arabica can reduce acidity, as they contain fewer acidic compounds naturally.
Origin Matters: Beans grown at lower altitudes, such as those from Brazil and Sumatra, tend to have lower acidity than those from high-altitude regions.
Alkaline Additives can Neutralize Acidity: Adding milk, cream, or a pinch of baking soda can raise the pH of your coffee, neutralizing some of its acidity.

Understanding Coffee Acidity and the Roasting Process

Acidity in coffee refers to two things: the flavor characteristic and the actual pH level. Many factors contribute to the final acidity of your brew, and the roast level is one of the most impactful. Darker roasts are subjected to higher temperatures for a longer duration, which reduces acidity. During roasting, a compound called N-methylpyridinium (NMP) is produced in higher amounts, which has been shown to reduce stomach acid production. This makes dark roasts not only less acidic in taste but also potentially easier on sensitive stomachs.

The Impact of Roast Level on Acidity

The roasting process is a major determinant of a coffee's final acidity. Light roasts retain most of the bean's origin flavors, which often include bright, fruity, or floral notes caused by higher levels of chlorogenic acids. As the roasting progresses to a medium level, some of these acids begin to break down, resulting in a more balanced flavor profile with muted acidity. Finally, the extended roasting of dark roasts diminishes acidity significantly, resulting in a bold, smoky flavor profile where the inherent acidity is masked by the roast character.

Comparing Different Roast Levels


Characteristic	Light Roast	Medium Roast	Dark Roast
Acidity Level	High	Moderate	Low
Flavor Profile	Fruity, floral, bright, and complex notes	Balanced, sweet, nutty, and chocolatey notes	Bold, smoky, bittersweet, and roasty notes
Roasting Temperature	179°C - 207°C (355°F - 405°F)	207°C - 218°C (405°F - 425°F)	218°C - 235°C (425°F - 455°F)
Visibility of Oils	None	Minimal	Noticeable, oily sheen
Chlorogenic Acids	High	Reduced	Decreased significantly
Stomach-Friendly Compounds (NMP)	Low	Moderate	High

Other Factors That Influence Low-Acid Coffee

Beyond the roast itself, there are several other elements that can help you achieve a less acidic cup:

Bean Type: Robusta beans are naturally less acidic than Arabica beans. While Arabica is known for more nuanced flavors, Robusta contains fewer acidic compounds, including citric and phosphoric acids, making it a viable option for those seeking a less acidic coffee.
Brewing Method: The temperature of the water used for brewing plays a significant role. Cold brew, which involves steeping coffee grounds in cold or room-temperature water for an extended period, can reduce acidity by up to 60% compared to hot brewing. This is because cold water extracts fewer of the bitter and acidic compounds from the grounds. Brewing methods like the French Press also produce a lower-acid cup compared to drip coffee.
Bean Origin: Coffee grown at lower altitudes tends to have lower acidity. Consider coffee beans from regions such as Brazil, Sumatra, and Guatemala, which are often naturally less acidic.
Alkaline Additives: Adding a small amount of an alkaline substance can neutralize the coffee's acidity. A pinch of baking soda can work, or you can add calcium-rich milk or creamer, which can help balance the pH level.
Decaf Coffee: The decaffeination process removes some of the phenolic acids, which can result in a slightly less acidic brew. This, combined with the absence of caffeine that stimulates stomach acid, can make decaf a gentler option for some people.

Combining Methods for the Ultimate Low-Acid Coffee

For the best results, you don't have to rely on just one technique. You can combine methods to create the perfect low-acid coffee experience. For example, start with a dark roast using naturally low-acid Robusta beans. Then, prepare it using the cold brew method. If you still prefer a hot cup, dilute your cold brew concentrate with hot water instead of brewing with hot water from the start. You can also add a splash of milk or a sprinkle of baking soda to further reduce the acidity and smooth out the taste. Finding your ideal low-acid coffee is a matter of experimentation and understanding the various factors at play.

The Rise of Stomach-Friendly Options

As more people become aware of the impact of coffee's acidity on their digestive health, the market for stomach-friendly coffee products is growing. Brands are now offering specialized low-acid coffee products that are specially roasted and processed to minimize acidity. Some brands even offer products that have been cold-brewed and then dehydrated to create a low-acid instant coffee, providing maximum convenience without the discomfort. This increased variety means that sensitive stomachs no longer have to miss out on the rich flavor of a great cup of coffee.

Conclusion

For those seeking a less acidic cup of coffee, a dark roast is the most direct solution, as the extended roasting process naturally reduces acidity. However, the best approach involves considering multiple factors: choosing naturally low-acid beans like Robusta, opting for the cold brew method, and being mindful of the beans' origin. By understanding these variables and experimenting with combinations, you can enjoy a delicious, flavorful, and gentle-on-the-stomach coffee that suits your personal preferences and sensitivities.

Frequently Asked Questions

Contrary to popular belief, a light roast coffee often contains slightly more caffeine per bean than a dark roast. This is because dark roast beans are roasted longer, which causes them to lose more moisture and density, making a scoop of dark roast contain less total caffeine by weight.

Brewing methods with lower temperatures, such as cold brew, extract fewer acidic compounds, resulting in a smoother, less acidic cup. Other methods like French press and espresso also tend to produce a lower-acid brew than drip coffee.

Yes, you can. To reduce acidity, use a dark roast, a coarser grind, and consider using the cold brew method. You can also add alkaline additives like milk or a pinch of baking soda to your finished cup.

While cold brewing generally produces a less acidic cup, the final acidity depends on the bean type, roast level, and brewing parameters like time and grind size. However, studies consistently show a significant reduction in total acidity compared to hot brewing.

Decaf coffee is generally slightly less acidic in terms of pH than regular coffee because the decaffeination process removes some of the acidic compounds. Additionally, the lack of caffeine means your stomach is stimulated to produce less acid, which can feel less irritating.

Yes, adding dairy-based milk or cream can help reduce coffee's acidity. The calcium and proteins in dairy act as a buffer, raising the overall pH level of the drink and creating a smoother, less acidic taste.

You can infer a coffee's acidity from its flavor notes and origin. High-acid coffees often have bright, fruity, or floral notes and come from high-altitude regions like Ethiopia. Low-acid coffees feature earthy, chocolatey, or nutty notes and are often dark-roasted.