Acidity in coffee doesn’t refer to the PH level, but is one of the basic taste characteristics along with body, aroma, sweetness, bitterness and aftertaste. Too little acidity can result in a flat or dull coffee.
Acidity is generally considered a positive for coffee, providing brightness to the flavor and enhancing other qualities. The organic acids in coffee contain powerful anti-oxidant properties that contribute some of the health benefits to coffee, but there’s a trade-off for some people.
There are some repercussions for people who have a delicate digestive system, in which high-grade coffee can cause acid reflux or otherwise upset the stomach due to increased concentrations of healthy organic acids. While those with normal digestive systems can handle the wonderful acids (that are beneficial to your health), there is a market for low-acid coffees.
Best Low Acid Coffees
A good starter point for low-acid coffees is by origin. While there is variation in the amount of acidity within a country (which are large and very diverse), it provides a start to narrowing down your choices. Some of the best low-acid coffee in the world come from:
Coffees grown at low altitudes have a tendency to develop less acids during the growing process, and are therefore the least acidic coffees. Dry (also known as “Natural”) processing also tends to result in a lower acid coffee.
Roast Level for Lower Acidity
Aside from selecting a low-acid coffee based on origin (and there are variations even within a country), the roast can play a part in lowering the acidity of the coffee. Typically derived from organic acids within the coffee, roasting longer will burn off more of the acids, removing them from the beans and therefore the drink once brewed. A darker roast will generally have lower acidity than lighter roasts, as the organic acids are burnt off during the roasting process.
The two primary organic chemicals in coffee that are associated with upset stomachs are N-alkanoly-5-hydroxytryptamides and catechols. On the other hand, some compounds such as N-methylpyridinium (NMP) have been shown to help settle stomachs – it’s NMPs that have been found at higher levels in darker roasts than lighter roasts.
Cold Brewing’s Effect on Low Acidity
Cold brew coffee tends to do very well for those who are sensitive to coffee, due to a lower extraction temperature of the coffee grounds over the course of many hours. Higher temperatures are required to extract some of the acidic compounds found in coffee, and these higher temperatures aren’t found when cold brewing.
Finally, adding milk or a milk substitute will help make the drink more palatable to your stomach.
Decaf as an Option for Low Acid
The process used to extract caffeine also pulls out many of the other compounds that naturally occur in green coffees. Regardless of how they’re decaffeinated – swiss water, CO2, other solvents – they lose more than just caffeine, which reduces the levels of other acids.
While any decaf method will pull out some of the “healthy” compounds, none of them will make coffee unhealthy. A common misconception is that solvents are less healthy than CO2 or swiss water, but they are burnt off at a much lower temperature than coffee is roasted at, leaving no trace of any compounds in the final roasted coffee.