How to Roast Coffee Beans: A Step-By-Step Guide

Last Updated on February 23, 2023

Roasting your coffee beans at home can add extra time and effort to brewing a fine cup of coffee. But is it worth it? For many coffee aficionados, it can be worth the extra effort, especially if you want to monitor the handling process of your favourite beans as much as possible throughout the roasting and brewing process.

Home roasting your beans has the potential to give you an extremely fresh flavour of coffee you have never experienced from instant or ground coffee. It takes more time and extra effort, but it can be worth it. If you have any questions about how to roast coffee beans at home, continue reading for a glimpse into the world of custom coffee roast skills.

Why Roast Coffee at Home?

One of the first and most obvious benefits of roasting coffee beans at home is learning a new and unique skill. Roasting beans can be straightforward for beginners to get started with, even if they use nothing more than a hot air popcorn popper as their home coffee roaster. Still, it also has several nuances you need to learn to get a perfect roasting result.

The most time-consuming part may be finding where to buy green coffee beans. The easiest way to find your own green coffee beans is by online sourcing sustainable beans in the variety you love. Or try some new varieties and see which one you enjoy the most. Because unroasted beans are far less expensive than their processed counterparts, you can buy more of your favourite beans for a lot less money than you would otherwise.

Roasting your beans at home also gives you a chance to taste coffee in its freshest form. When you roast your coffee beans at home, you will know exactly where your coffee was sourced and its process to get to your cup.

Sourcing Your Favourite Beans

You can decide whether or not you want to purchase beans from a certain region. Nowadays, you can easily connect with local coffee bean suppliers online. Some even offer brewing guides on their webpage for a better coffee experience.

Saving Money on the Cost of Beans

Fresh beans are less expensive than roasted beans, so you can get more for your money. More than that, cliche as it may sound, fresh is always better. Aside from the great aromas and taste that you can get from freshly ground coffee, you can always roast it to your preferred level and even control the grind size, which greatly influences the coffee’s flavour.

Roasting to Your Preferred Level of Darkness

Decide how long you want to roast your beans, and switch it up every time for different flavours.

Getting the Freshest Ground Coffee Possible

Raw, unroasted beans store for a very long time so you can roast and grind your beans as needed.

Allowing Yourself to Sample a Variety of Coffee Varieties

You won’t be limited to a single variety from a local source anymore!

More Reasons to Roast at Home

Also, since you can determine how long you want to roast your beans, you directly control the flavour and caffeine levels the result will provide. Beans with a light roast can give off a complex and pleasant mix of flavours with an abundance of caffeine to get your day started. A medium roast can unlock earthy undertones and robust aromas. And dark roast beans can produce a sweet and smoky cup of brew with hints of caramelised flavour profiles.

Roasting your own beans can take up to 20 minutes to create around a pound of coffee. While this might not be much time overall, you should remember that you will need to roast a new batch of beans every time you run out of coffee. Darker roasts, city roasts and some popcorn machine roasting progress much slower than other methods, so keep this in mind before starting.

Basic Home Coffee Roasting Process

Step 1

Obtain your green coffee beans from an online or local source. Make sure you get a variety of green beans that you know and love, or be bold and try something new and unique to see how you like it. Unroasted green coffee beans are normally much cheaper than those roasted evenly, so you may be able to afford multiple varieties to try.

Step 2

Place your beans into your roasting pan. You can use a variety of heating elements for this process, including a cast iron pan on a stovetop, a stovetop popcorn maker, or a specific coffee roasting machine. You can also try oven roasting on a baking sheet, though this can sometimes be unreliable for roasting coffee beans.

Step 3

Increase to medium heat and stir your beans with a wooden spoon. Some popcorn makers and most bean roasters will not require you to stir as they include automatic stirring bars. If you are using a pan on a stove, always move your beans around to prevent an uneven roast continuously.

Pro-Tip: Improper stirring will result in a batch of beans at different roasting levels. Some will be light, others will be medium, and the remainder will be dark. This can lead to poor tasting coffee.

Step 4

Remain close to your roasting beans and monitor their progress with your eyes and ears. Continue stirring the beans and keep them evenly spread around the pan. Once they have reached your desired roasting level, remove them from the heat immediately. They will rapidly change to a light brown colour, so keep a close eye on the hot beans.

• Light Roast: This is just before the beans go through their first crack. If you remove them at this stage, it would be considered a light roast coffee bean. The temperature of the roasted coffee bean is usually 360 to 400 degrees Fahrenheit. Remove them before the first crack for a cinnamon roast or an even lighter roast.
• Medium Roast: This is normally at the point of the first crack or slightly after it. The espresso roast coffee bean temperature is usually 410 to 430 degrees Fahrenheit. If given a very even roast, the roast character of medium beans is excellent for an iced coffee or espresso.
• Medium-Dark Roast: Roasted coffee beans at this stage are normally right in the middle of the first crack and second cracks. You can start to see this around the 420 to 440 degrees Fahrenheit range.
• Dark Roast: Right at the point of the second crack, though longer roasting is fine for dark French roasts. The darker roast coffee bean temperature is usually 430 to 480 degrees Fahrenheit.

Pro-Tip: Never roast your coffee bean to more than 480 degrees Fahrenheit. The sugars have burnt, and the oils are starting to burn. This is beyond a dark French roast, and the finished cup of coffee will be bitter and undesirable. If you get past this temperature, your coffee bean has been ruined, and you should try roasting coffee again.

Step 5

After removing the coffee beans from the heat at your chosen roast level, it’s time to separate the chaff from the bean. The chaff is the skin of the coffee bean, which likely flaked off during the roasting process. To separate this skin, you can use a metal colander or chaff collector specifically made for roasting beans.

Pro-Tip: The chaff can be flammable and should always be removed from your roasting pan, popcorn popper, or other appliance before roasting other beans. When handling hot baking sheets or cast iron pans full of roast coffee beans, don’t forget to use oven mitts.

Step 6

After the beans have thoroughly cooled, store the cool beans in a container overnight, but ensure the container is not airtight. You want the coffee bean to be able to degas and develop its final flavours overnight.

Pro-Tip: Not allowing your freshly roasted coffee beans to degas properly can leave a bitter or rancid flavour on the coffee. Always be sure to give the coffee several hours to cool and degas.

Step 7

Around 24 hours after the roasting process, your coffee bean will have developed its best flavour. This is the perfect time to grind them and brew your first cup of amazing coffee. The remaining coffee grounds should be stored in an airtight container to protect the grounds from moisture and oxygen.

What Is the First and Second Crack?

Coffee beans will go through the first and second cracks during the home roasting process. This is how you can determine how far along in the process you may be. As a bean roasts, it darkens in colour and oils from the inner seed start to permeate and collect on the surface.

The Beginning

The liquid inside the bean will start to steam, causing the bean to expand. When the roasting bean hits 400 degrees Fahrenheit, you will notice the distinct sound of the first crack. Some coffee connoisseurs can know when the first crack is close to happening simply by the change in the smell of the roast. The natural sugar inside the bean will start to caramelise, giving off a distinct and changing aroma as more and more steam builds up inside.

Light or Medium Roast

If you are going for a light or medium roast, you will most likely remove your beans from the heat immediately after the first crack. This will give your finished

cup a smooth and sweet flavour with a robust profile with no bitter or overly earthy aroma.

Second Crack

You will hear the second crack somewhere between 440 and 450 degrees Fahrenheit. Even for experienced coffee roasters, the second crack can be somewhat unpredictable and harder to hear. As such, keep a close eye on your roasting process. Please do not depend on the sounds it produces.

The second crack stage is where the oils from the inner part of the bean start a chemical reaction that causes them to rise to the bean’s surface. By this part of the roasting process, the colour of the beans is extremely dark and near black. This is the stage where the French roast is created. However, the window between French roasted beans and burnt beans is extremely small, so always keep a very close eye on your roast and remove it from the heat immediately once it reaches your desired colour.

Quick Notes:

• The first crack happens around 400 degrees Fahrenheit.
• You will hear a distinct sound when the first crack happens.
• This is when you would stop roasting light or medium styles of coffee.
• The second crack can happen at 440 degrees Fahrenheit.
• The sound will be much quieter than the first crack, so listen closely.
• Coffee can go from dark roast to being burnt quickly after this point, so keep a close watch!

Locating Green or Unroasted Coffee Beans

The easiest way to find unroasted or green coffee beans is online for most people. A range of suppliers can obtain beans directly from the source, giving you full control over the varieties you obtain and the locations you support with your purchase.

You may be a lucky few with a local coffee shop in your area specialising in unique brews. If this is the case, visit your local coffee shops and see if they have a selection of unroasted fresh beans to sell. Explain your interest in home roasting and why you want to try roasting your green beans. They will be just as passionate about proper coffee roasting experiences as you are.

In addition to connecting with local coffee aficionados that can appreciate a delicious coffee, you build up a network of like-minded friends and business relationships, which can be a huge benefit in the future if you decide to source rare or unusual varieties of unroasted coffee.

Tips About Green Coffee

Unroasted coffee will smell very different from its roasted stage, so don’t buy beans based on aroma alone. Most unroasted coffee will share a similar earthy smell, regardless of their varieties.

Don’t hesitate to buy more unroasted beans than you think you need. The roasting process will remove the water weight from the beans, and you will lose a good amount of overall weight from raw to roasted.

If you are new to purchasing unroasted beans online, look for a vendor that lists flavour profiles and various information on their sale pages. You should be able to see if the bean is Arabica or Robusta varieties and where it has been sourced.

Things to Know About Home Roasting

While home roasting your own coffee beans can be an exciting way to create your own brew, it can be time-consuming and confusing for beginners. Before you dive into your first roasting process, there are a few things to know.

• Roasting coffee smells much different than brewing coffee. If your roasting smells bad, don’t assume the batch is ruined. Instead, give it a full chance to roast evenly and develop its final flavour after cooling before you decide.
• Always roast in a ventilated area or use a fan above your stove when roasting indoors. It will help with the roasting and slightly burnt smell, especially if you are going for dark roasts, a Vienna roast, city roast, or French roasts.
• Unroasted coffee will expand during the roasting process giving you more beans for your buck in size alone. However, they will lose most of their weight due to evaporating steam as the roast progresses.
• Unroasted coffee beans are normally much cheaper than dark roast varieties. You can afford to buy a few varieties or larger amounts of your favourite variety while remaining within a set budget.
• Raw coffee beans will last much longer than light brown roasted beans. Always only roast as much as you plan to use in about a month or less time. Unroasted coffee can be stored for as long as a year with excellent results.

Get Roasting

If you value flavour and freshness when it comes to your cup of coffee, learning how to roast coffee beans on your own is an excellent way to maintain full control over these aspects of the process. While it might be a bit more effort on your part, the result may very well make home coffee roasting worth the effort.

You’ll also be lucky enough to be able to sample a wide range of new and unique varieties, especially if you order raw green beans from other countries. In addition, beans found in your local area may be lacking in a certain aroma or trait you may be searching for.

If you have never experienced an extremely fresh, home-roasted brew, you miss out on some unique flavours of coffee at home. If you have the motivation and willingness to locate the best raw beans and take the time to get them to lightly roasted perfection, you will be astounded by the quality of the cup you can create and enjoy to start your day.