How Does Roast Affect Coffee?

Thank you for visiting our site. We have been a trusted and expert coffee authority for over five years. The support of our readers and members sustains our site. Should you purchase products from retailers through links or adverts on our site, we may earn commissions at no additional cost to you. As an Amazon Associate, we earn from qualifying purchases made on Amazon. These commissions are vital in maintaining the operation of our site. We curate some content and strive to provide valuable links to some of the best places on the internet. Please read our disclaimers policy for more information. We trust you will enjoy our site!

The roast of your coffee immediately impacts the flavor, caffeine content, and the color.

Without roasting your beans, you’d just be taking some oily plants and dropping them into some hot water, more or less.

Roast is one leg of this three-legged table we call coffee. It’s about roasting, grinding, and your brewing methods, but the latter two can’t happen if you don’t get the roast right.

Depending on how the coffee is roasted, it will dictate the flavor profile. There are basically three main profiles that are directly affected by the roast level.


For those of you who enjoy coffee, but don’t want to be assaulted with the high acidity or rough coffee flavor, this is your best bet.

Mild flavor profiles are achieved through light roasting. This is the optimal coffee to add cream, sugar, and flavors to.

You can usually match or mask the coffee flavor with enough sweetness, which is more difficult in other flavor profiles.


There’s no better way to describe it than this: bold.

There’s a stronger coffee flavor, but it isn’t overpowering. You’ll find that medium to medium-dark roasts come out with a bold flavor profile.

If the coffee beans in question have a nuttiness or chocolate flavor to them, this roast is optimal for bringing those flavors out, and making them shine.

Extra Bold

Here, you’re getting into dark roast coffee.

There’s more boldness and power in each sip, and it’s not necessarily sharp, it’s just very pronounced in every single cup.

Dark roast coffee can be cut with a spoonful of sugar, though many people think it’s criminal to add anything more than that and mess with the flavor or mask it.

What is Coffee Roasting?

Roasting Coffee

Coffee roasting is just what you’d expect: taking coffee beans, and roasting them in a controlled environment.

Since we’re dealing with a lot of acidity and nutrients here, you want to preserve the integrity of the coffee as much as possible.

There are different methods or recipes for roasting beans, some of which are proprietary information from major brands.

Coffee roasting is like a lightweight version of making popcorn.

You have to hear two pops in a coffee bean (one for oxygen, one for carbon dioxide) to know that it’s reaching the necessary roasting level.

Commercially, there are two different ways to roast coffee that are in practice all over the world.

The beans, which are green at their time of extraction, are loaded into roaster drums or barrels where the heat is turned on.

The methods differ based on the heat source, which could either be extremely hot air being forced onto the beans, or a heat source beneath the drum/barrel.

From there, the coffee roasts for a specific amount of time (dependent on the roast you’re going for), and then it’s cooled using a method known as quenching.

Boom, you have roasted coffee beans.

The roasting process turns the green of those beans into a light brown or black based on the roast level that you’re going for, and brings out all the nutritional benefits through a chemical breakdown.

Coffee Roasting Levels

There’s five roasting levels that are used to make a myriad of coffee flavors and profiles, but since roasting beans is basically a perfected science at this point, this is how it’s done.


Holding Coffee Beans

These are untouched beans and are not roasted. Some people swear by the flavor and body of green coffee beans, but the thing is… there isn’t any.

We’re not poking fun, but there’s no actual coffee flavor whatsoever. You get that signature coffee taste from the roasting process.

It breaks down what very little sugars are in coffee to caramelize the beans, decrease polysaccharides, and proteins. All of those impact taste.

Green coffee has a strong bitter taste, primarily because the chlorogenic acid (antioxidants) is not broken down through roasting, so you have approximately 2.5x more of this than you would with roasted beans.

That has health benefits, but it’s far from enjoyable.

Light Roast

Coffee Beans Light Roast

This is the most common coffee bean roast that you’ll find. It’s basically all the coffee that you can find from major chains and makes up most of their popular options.

Light roast has a bit more acidity than dark roast but arguably comes with more original coffee flavor.

These beans are subjected to a lower temperature than their counterpart roasts but will remain there for longer until you hit the “first crack,” which is when the first bean begins to release oxygen and carbon dioxide.

If you currently purchase any type of coffee labeled as a breakfast blend or a New England blend, they’re likely to be made from light roast beans.

Medium Roast

Coffee Beans Medium Roast

Medium roasts come off some time in between the first and second crack, and as a result, they can be pretty inconsistent.

You don’t see a lot of medium roasts in commercial uses, but it is prevalent in pre-ground pound coffee bags at the supermarket.

You still get that great, grainy flavor of light roast coffee, but with a bit more of a punch in the taste buds.

If you’ve ever heard of a standard city roast, American roast, or breakfast roast (not to be confused with breakfast blend), it’s likely to have been made with medium roast coffee beans.

Medium-Dark Roast

Coffee Beans Medium Dark Roast

This is the bridge between dark roasts and medium roasts.

They’re set to go off at the second crack, which gives a bolder flavor and a darker appearance. There’s a medium blend of acidity here, but a slightly less volume of actual coffee flavor.

Medium-dark roasts are excellent for blending with frozen beverages or using to create something that includes coffee.

It’s dark enough that the flavor doesn’t get lost, but not dark enough that it drags down the sweetness of a shake or frap.

Dark Roast

Coffee Beans Dark Roast

This is the smooth and less acidic flavor that many coffee lovers – love!

If you’re having three or more cups of coffee per day, then you’ve likely had your fair share of acid reflux or notably acidity in your stomach from ingesting a lot of lighter roast coffee.

Dark roast is roasted at a much higher temperature, but usually only for about eleven-or-so minutes until they reach the optimal level.

There’s less acidity, but there are also fewer health benefits since chlorogenic acid and proteins are in lesser volume.

Dark roast has a pronounced robust flavor that hits the spot when lighter roasts begin to taste watery.

If you’re planning on roasting these at home, just know that dark roast is tricky to time just right.

How Does Roasting Affect the Taste?

Young Woman Drinking Coffee

It changes everything about it.

During the process, melanoidins are released from coffee beans due to the chemical composition change.

You need to roast the beans for this to be effective, but after a certain point, you could end up burning the beans and turning them into a lump of carbon.

It’s an art and specific science that you need to get right.

It’s also what gives it that rich brown color and aroma that we love so much. Sight and smell factor into taste so the color is also going to be a big part of the flavor experience.

One major change that happens is based on temperature and exposure time, and it’s how oily your coffee might become.

Darker roasts typically have more oil since they’re roasted at a higher heat.

Darker roasts reach higher temperatures, though they have much less roasting time than light or medium roast variants. There’s a bitter taste that remains, but usually no acidity.

The highest concentration of chlorogenic acid in coffee is found while it’s still green, though it isn’t nearly as well metabolized in the body (and to put it bluntly, the flavor of green coffee is not that great).

Lighter roasts will have more acidity, which is why we traditionally add some form of creamer, sugar, or flavorings to moderate that acidic taste.

Can I Roast Coffee at Home?

You can, but it’s tricky business.

If you’re trying to emulate the same flavors as your favorite branded coffee beans and coffee house varieties, it has its difficulties.

You can roast coffee beans at home in your own oven, or purchase a coffee roaster (though they are a bit dodgy when they’re in the lower price range).

It’s not an overly egregious process, but it does take a bit of commitment to getting your coffee just right.

Most countertop roaster drums come with sufficient instructions, but there are plenty of guides available to get unique-tasting roasts and those in-between colors that you don’t see in pre-ground coffee or pre-roasted beans.

It’s a lot of fun to experiment with adding flavors to the beans while they roast, imbuing the aromas and new tastes into the beans from the moment the roasting process begins.

Amazon and the Amazon logo are trademarks of, Inc, or its affiliates.