Roasting Temperature Affect The Acidity Of Coffee


Brewing coffee is an art, but brewed coffee's acidity depends on the roast level. Roast levels and coffee are the most important factors to consider regarding drinking quality and flavor. Some roasters use subtle changes in roast or roast level, such as natural airflows, to achieve different tastes and flavors.

In general, lighter roasts have a fuller flavor with less acidity. A medium roast will have a more balanced flavor, while a dark roast can be robust with almost no acidity. Because Lightly roasted beans are pretty acidic with a low pH of 4.5-4.8, medium roasted beans are less acidic with a pH of 4.8-5.0, and dark roasted beans are very low in acidity with a pH of 5.2-5.3.


Moreover, coffee creates by brewing the ground coffee beans with hot water, which releases a compound known as caffeic acid. The specific roast level of the beans usually determines how much caffeic acid is released. And it can potentially affect the flavor of the coffee.

So, it is no secret that acidity is one of the main drivers behind the taste of coffee. That's why it is essential to understand what drives the levels of acidity in the coffee you drink.

This blog will look at the different types of roast levels and how they affect the acidity of brewed coffee.

Acidity Levels Are Different For Coffee Roasted At Different Levels

Acidity is one of the four basic tastes that we can distinguish. This one pronounces as tingling sensations in the tongue. Edge is essential to coffee. Because it gives coffee its specialty and flavor. It is why coffee with low acidity tastes bland.

If you are using a coffee maker at home, then the time taken for coffee to drip through the filter depends upon the number of coffee grounds and the strength of the coffee. If the acidity levels are high, the coffee will have a strong taste.

Acidity levels are different for coffee roasted at different levels

The acidity levels in coffee depend mainly on the roasting time and temperature, and to a lesser extent, on the degree of roast.

Different levels of roasting produce different acidity levels. Coffee is usually light roast to develop a milder flavor. Darker roasts tend to bring out the bolder and richer characteristics of the coffee. But the difference between light and dark roasts is not in acidity level but caffeine content. Unsurprisingly, light roasts have higher caffeine content than dark roasts. Because the longer coffee roasts, the more caffeine gets destroyed.

Besides, acidity is one of the main factors affecting coffee quality. It is directly related to the freshness of the beans. When longer it takes to roast coffee beans, the more acidity they will have. Roasting coffee beans for a shorter period will result in less bite.

Roast Levels: Light, Medium, Dark

Roasting coffee beans is when coffee beans roast in an oven or on a grill. The beans can burn at different temperatures to give different roasting levels. Roasted coffee beans will create a different flavor and aroma depending on the roasting levels.

roast level

Light Roast:

Lightly roasted coffee beans are green beans that roast at lower temperatures to preserve their natural flavors. The beans can burn at temperatures of less than 400 degrees Fahrenheit. They roast until they are light brown. If a bean roasts longer than that, it will become bitter and lose the original flavor.

Its flavor is fragile and watery. It has slight and is generally not very flavorful. Therefore, It can use for espresso and iced coffee drinks. Europeans prefer light roast.


Light roasts typically roast for 12-14 minutes. Fair roast coffees generally are lower in caffeine and have a sweet flavor profile. And they are easier to drink black. But Light roast coffees are the most acidic and have the least amount of body. The acidity of these coffees can balance by adding milk or cream. If you like a lighter, less complex taste and aroma, you may enjoy a lighter roast.

Medium Roast:

Medium roasted coffee beans are green beans that roast at medium temperatures to enhance their flavor. It has an even, balanced flavor between fruity and sweet, with a hint of chocolate notes on the finish. The beans roast until they are medium brown. Medium roasts are a bit mellower in flavor with a fuller body. But still less intense than dark roasts. These coffees also pair well with milk or cream.


Medium roasts roast for 15-17 minutes. But if you roast the medium roast beans for a more extended period at a higher temperature, which gives it a darker color and less natural flavors. The medium roasts use for drip coffee.

Dark Roast:

It's also known as Italian or Continental extra dark roast. It has intense, almost chocolaty flavors, and it sits very intensely. It has a bitter and dark taste. The darker roasts can use for percolators and French press.

Dark roasted coffee beans are green beans that roast at high temperatures. The beans roast until they are dark brown. Americans prefer dark roast. Dark roast coffees are typically higher in caffeine, have a more intense flavor profile, and take longer to brew.


The darker roasts roasting process destroys some vitamins and minerals. They have more carcinogenic chemicals, and darker roasts are bitterer. But some people love dark roast. Dark roasts can roast for 18-20 minutes. They are robust and full of flavor.

Frequently Asked The Question:

How Does Roast Affect Acidity Levels?

Acidity and pH levels are two concepts that affect the brewing process. That is why roast affects these two parameters. However, the roast level can also be affected by many other factors like pressure, water temperature, and many more. All these things influence the acidity level of brews, so it is best to understand them and their effects on the brewing process.

What Does Science Say About The Different Roast Levels?

Roast levels are a matter of personal preference, but there is no scientific evidence to suggest that one roast level is healthier than another. The only difference is the flavor and texture of the coffee.

But you can determine the roast level by the length of time the coffee beans can roast. Light roast beans burn for a short period, while dark roast beans roast for a more extended period. Dark roast beans have more caffeine than fair roast beans because they have exposed to higher temperatures, which breaks down the bean's natural sugars.

What Is The Best Roast For Acidic Coffee?

Several roasts work well with acidic coffee. With the different methods, the taste of the coffee will also be different. But Americans prefer the darker roast rather than the lighter roast because the Dark roast has a more complex flavor and is more full-bodied.

Similarly, some experts consider light roast the best roast for acidic coffee. Because it cannot overpower the acidity in the beans. So, the best coffee roaster is what you like the most.

How Can The Roast Level Affect The Taste Of The Coffee?

Coffee roasted longer (darker) tastes more bitter. Roasted coffee has more of the chemical compounds that make coffee taste bitter. So, it isn't easy to taste the real taste of coffee. Roasting the coffee bean for a short time can make the bean's surface can still keep the original shape and won't change the chemical ingredient. Then, we can enjoy the natural taste.


In conclusion, you can say that the roast level of a coffee bean is a measurement of the bean's darkness. Darker roasts have more caffeine and a bolder, intense flavor. The lighter roasts tend to be milder and more acidic. The acidity of coffee can be a good thing or a bad thing, depending on your preferences if you're looking to try a new coffee. But don't know where to start; you might want to consider two or three different roasts.

Roasting should be done in a dark-roasted medium, light-roasted medium, or medium-light roasted manner to produce different tastes and flavors since different roasts will yield different results. Different roasts will have different flavors and levels of acidity.

We hope this article has helped you see the different types of roasts available. And how they can affect the acidity of brewed coffee. Thank you for reading and see which one you prefer.