Can You Roast Coffee Beans a Second Time?


Coffee is the fuel of nations, the drive behind economies, the transformative substance that turns zombies into humans, but many variations for roasting and drinking surround this invaluable product. With so many different avenues to go down, the possibilities are endless.

Can you roast coffee beans a second time? Roasting coffee beans actually does not roast them at all, it simply cooks the bean. By reheating the bean, a more robust flavor is not produced, but rather those that are burnt or bitter. It would then be advisable to avoid reroasting coffee beans and instead purchase a darker roast or roast your own beans for a longer amount of time.

There are those that prefer to drink their coffee with a milder flavor doused in cream, but others tend towards a stronger, bolder sip. It may seem like a quick solution to create a richer taste in your coffee beans to roast them a second time, but this action could result in the total spoiling of your original beans. Continue reading to find out if you can get your beans darker by roasting them a second time, how the roasting process works, and the different types of roasts,

Can You Roast Coffee Beans to Make Them Darker? 

So you have either opened up a bag of beans or you have made your own batch but your coffee is falling short in color and flavor. This shortcoming leaves you pining for coffee beans that are darker and deeper in flavor. With this delmia, you have a lightbulb moment and ask “Why not just roast them a bit more on my own?” This idea is one that, in a sense, seems logical. However, can roasting that batch again really give you proper results? 

When roasting coffee beans, heat plays an essential part in the chemical reaction within the beans to create various flavors and colors. Coffee beans start out green and then through roasting, are heated to different levels which helps to produce an even internal temperature to get the beans to the first, second, or third crack depending on the desired flavor. 

Once the coffee beans have been roasted to perfection and have cooled, the chemical process that happens during the roasting process stops and cooking is complete. If you take the coffee beans that have already undergone roasting, the essential chemical transformation, called the Maillard reaction, is needed to create flavor and color cannot be started a second time. 

The Mailliard reaction is an essential part of changing the flavor of coffee beans. Through this process, there are over hundreds of compounds that are transformed within each coffee bean through their decomposition. The roasted beans release CO2 and help to aid in the preservation of your beloved coffee beans through the displacement of oxygen. This reaction is complex and thus is a one-and-done sort of process.

Because of this inability to restart the needed chemical process, the coffee bean will not be roasted a second time, but will be more so cooked. When you reheat and begin cooking the beans, oils that give flavor are burned on the outside of the bean. 

When these oils are burned, the flavor reflects exactly that: a scorched coffee bean. Once this has occurred, the flavor of your coffee beans are certainly not made richer, but they are likely ruined. 

Have you ever had a cup of day old, overheated, scaled gas station coffee after a long hard day of road tripping? It is truly one of the most disappointing experiences in life, one not many forget, as that cup of coffee was their saving grace amid cramped cars, stale clothes, and crumpled up chip bags. 

If you roast your coffee beans a second time, the outcome will likely look something like this. Grab yourself another bag, or try again with your own roasts to avoid such a scenario. 

What is the Process of Roasting Coffee Beans

To roast coffee beans, do the following simple steps: 

  1. Pick fresh beans. 
  2. Choose a roasting method. 
  3. Store the beans.

Now that you understand why you likely should not roast your coffee beans a second time, it could be helpful to understand the roasting process itself for your beloved morning, afternoon, night, midnight, all day everyday drink. 

At first glance, it seems like roasting coffee beans would be a relatively cut and dry sort of process, but do not be fooled, there is an art and science that exists to this process and a pride behind the results. 

Since we are entertaining the idea of roasting your coffee beans a second time, let us assume that you are attempting to roast your own coffee beans from the comfort of your own home. Of course, coffee producers will roast their beans through more industrious processes, but there are ways for the at-home-coffee-connoisseur to get their most preferred roast. 

1. Pick Fresh Beans

If roasting from home, you first want to pick out the most perfect beans. The coffee beans you choose must be fresh. To be sure they are fresh, the coffee bean will be a nice green color. 

If there is any browning, then skip the bunch and find another option because fresh beans mean the best coffee. You also want to make sure that the beans are mostly alike in shape as well as size. This indicates a better quality bean which means, you guessed it, better coffee!

2. Pick Your Roasting Method

Second, you want to pick your roasting method and get to roasting. There are a few different ways to roast, however, let’s focus on two of the most user-friendly and most likely options for those of you at home: roasting beans in a pan on the stovetop and roasting using an in-home coffee roasting machine. 

Pan Roasting

For pan roasting, you want to make sure that you are not using a non-stick pan, go for something more along the lines of a cast-iron skillet. Once you have your skillet, get your pan to a medium heat. Add a relatively shallow layer of beans to the pan and stir them without fail to make sure they heat in all the right ways. For a dark roast, you want to wait around six to seven minutes to hear the sound of the second crack. 

Once you hear the crack, dump those dreamy beans into something or onto an area that they can cool down on. You need to leave your beans uncovered and exposed for twelve to fourteen hours to ensure that CO2 can escape from them and they are thus de-gassed. 

Using an At-Home Coffee Roaster

If you already possess or are wanting to up your game as an at-home coffee roaster, then a coffee roasting machine is your next best friend. What is so nice about the coffee roasting machine is that you are able to control the temperate more easily than a pan which helps to produce more uniform roast levels. 

Once you have your chosen coffee roaster all there is to do is follow instructions to add and begin roasting your beans. Different models vary, but the process should be relatively easy and mostly uniform across brands. Once you have your beans in, listen for that cracking sound around six to seven minutes for a darker roast. 

Some machines may have their own cooling processes, so be sure to see if this exists before you pull your beans out. If your machine does not have a cooling component, remove the beans and allow to cool just as with pan roasting. Once they have cooled, leave them to release gas for at least twelve hours. 

3. Store Your Beans

Third and finally, you want to make sure that all your hard roasting work does not go to waste by storing your beans properly. The biggest factors for storage are to have an airtight container, to make sure that the beans are stored in a solid container, and are kept in a cool area. 

The airtightness helps to keep the right amount of gas within the storage container to keep your hard-earned beans fresh. A solid container is also important to help retain all those yummy gases that benefit your beans. Lastly, be sure to keep your beans in a cool area and avoid warm spaces to keep the beans from releasing those gases and getting stale at an accelerated rate. 

Different Types of Roasts 

There are three basic types of coffee roasts including:

  • Light Roasts 
  • Medium Roasts 
  • Dark Roasts 

Of course, if you are not in the mood for a dark luxurious roast, there are ways to get a brighter, less deep taste in your cup of joe. If you are at home or around the corner and your favorite spot, it is likely they will have a multitude of roasts to suit your flavor of the day, but generally, there are three types of roasts, no matter how they have been named. 

Light Roast

First, you have your light roast coffee. A light roast coffee tends to be very mild and is usually light brown in color. The coffee bean itself will look a bit dry as little oil is produced through roasting. This roast is achieved quickly and if you are in a bind at home, can be a fast solution to roasting your own. 

Medium Roast

Second, there are medium roasts. Medium roasts have a stronger flavor than light roasts, but are not too intense. The beans with medium roasts are also relatively non-oily and tend to have a more balanced flavor all around with a leveled amount of acidity. 

Dark Roast

Last, there is the dark roast. This roast is very dark in color, has a heavy and very full flavor. The bean of a dark roast has more evident oil on the surface which can produce a nice shine. Once swallowed, dark roasts tend to leave behind a more bittersweet taste. 

Tim S.

Tim loves roasting, brewing, and experimenting with coffee. After years of perfecting this craft, working as a barista, and owning a small coffee service in college, he has decided to share his knowledge with the world.

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