How To Roast Your Own Coffee Beans At Home | Simple Guide
Coffee lovers who dream of a perfect cup of coffee know that buying coffee from a supermarket or Amazon often won’t fall into the category of “perfect.” Even when you buy freshly roasted coffee grounds from a great roaster, you’ll miss out on the extra freshness of freshly roasted coffee beans.
There's something special about roasting coffee beans at home (in addition to making your home smell divine). By learning how to roast coffee beans perfectly, you'll be able to create a coffee bean roast exactly how you want it. You can also experiment with blending coffee beans from different origins or processing methods. You might not always get perfect results right away, but the journey to the perfect coffee roast is fun and educational at the same time.
In this comprehensive guide, you'll learn more about the necessary equipment, which green coffee bean to choose, which roast level is best, and much more about roasting coffee beans at home.
Note: Detailed instructions about each roasting method will be covered in a separate guide.
Coffee Roasting Basics
Phases of the Roasting Process
Coffee roasting is a careful craft that transforms green coffee beans into the aromatic and full-flavored beans we love. The process occurs in three distinct phases: the Drying Phase, Caramelization (where Maillard reactions take place), and the Development Phase, starting with the first crack of the beans as they release steam.
Drying Phase: In the Drying Phase, the beans turn a yellow hue and expel moisture, giving off a grassy scent. This lays the foundation for further development.
Caramelization: This crucial second phase is where Maillard reactions enhance the complexity of flavor and aroma. During this phase, the beans undergo chemical transformations that shape their distinct flavor profile.
Development Phase: As the beans achieve a light to medium roast level, they produce an audible crack as steam escapes. This sound, known as the "first crack," marks the beginning of the Development Phase. From here, the beans progress, eventually reaching darker roasts.
The final phase of the roasting process is a rapid cooling phase. Why rapid, you wonder? Well, if you don’t cool the beans down quickly, they won't stop roasting immediately, and you want to stop the roasting progression as soon as you achieve your desired roast level.
Rapid cooling can be achieved by putting the beans on a cooling tray or in a colander and blowing cool air over them (a fan works well for that).
Don’t cool your beans by pouring cold water over them!
Step 1: Choose Your Roasting Method
Roast Method Options
Stovetop Roaster: Cast Iron Skillet
What it is: A stovetop roaster with a cast iron skillet is a popular and traditional method for roasting coffee beans. It's a basic method to roast green coffee beans in a cast iron pan over a stovetop burner.
Cost: Relatively inexpensive, as most people only need a cast iron skillet.
How to roast coffee beans with it:
- Preheat your cast iron skillet on your stovetop (usually medium-high).
- Add your green coffee beans and stir continuously using a wooden spoon or spatula.
- Pay attention to the beans' color change and listen for the first and second cracks.
- Once you reach the ideal roast level, quickly cool the beans.
Difficulty level: Medium to advanced.
This method gives you good control over the roast but requires constant attention and manual stirring. It's probably not the easiest method for beginners. Still, it's perfect for coffee lovers who enjoy being directly involved in the process or don't have the space for other equipment.
For a more detailed instruction see our guide on How To Roast Coffee Beans In A Cast Iron Skillet
Air Roasting: Popcorn Machine
Important notes:
- A popcorn maker is called a popcorn maker for a good reason. You’re only supposed to pop popcorn in it. While you can use a popcorn popper to roast coffee, doing so will void your machine’s guarantee. Roasting coffee may also shorten the machine’s life cycle.
- Only use a popcorn popper that has heat sources on the side, not on the bottom.
- Never leave popcorn machines unattended when roasting coffee beans, and always clean the machines thoroughly after each batch to reduce the risk of fires.
What it is: Air roasting with a popcorn machine is a convenient and hands-off method for roasting coffee beans. You're using a hot-air popcorn popper to roast green coffee beans instead of popcorn.
Cost: Popcorn machines are relatively affordable these days.
How to roast coffee beans with it:
- Place the green coffee beans into the popcorn popper.
- Turn the machine on.
- Pay attention to the coffee beans' color and listen for the sound of the first and second cracks.
- Once you reach the ideal roast level, quickly cool the beans.
Difficulty: Easy, but potentially a fire hazard.
Air roasting is relatively hands-free and user-friendly. It is an acceptable choice for beginners but shouldn't be a long-term solution.
For a more detailed instruction see our guide on How To Roast Coffee Beans In A Popcorn Popper
Oven
What it is: Just your standard kitchen oven! You’ll spread green coffee beans on baking paper and roast them in a conventional kitchen oven.
Cost: You probably already have an oven; if not, this can be a rather expensive way to roast coffee beans.
How to roast coffee beans with it:
- Preheat your oven, usually to around 450°F (232°C).
- Spread your green coffee beans evenly on a baking sheet.
- Put the baking sheet with the beans in the oven.
- Pay attention to the beans' color change and the progression of cracks.
- Once you reach the ideal roast level, quickly cool the beans.
Difficulty: Easy.
Oven roasting is relatively straightforward and accessible for most home roasters.
For a more detailed instruction see our guide on How To Roast Coffee Beans In The Oven
Drum Roasters
What it is: A drum roaster is a dedicated coffee roasting machine. It provides precise control over temperature and agitation. A drum roaster is a rotating drum where coffee beans are roasted evenly.
Cost: Drum roasters are expensive and considered an investment. The cost can vary significantly depending on the brand and capacity of the roaster.
How to roast coffee beans with it:
- Put your green coffee beans into your drum roaster.
- Set the roaster to the desired temperature and time.
- Check the coffee beans' progress through the roaster’s viewing window or by sampling the beans at various intervals.
- Cool the beans rapidly once the ideal roast level is achieved.
Difficulty: Advanced.
Drum roasters provide the most control and consistency, but there's a bit of a learning curve. They are best for experienced roasters or home users who are truly committed to mastering the art of coffee roasting.
Step 2: Select Your Green Beans
Of course, it's not enough to have great roasting equipment. It would help if you also had good green coffee beans. You might be overwhelmed by the wide variety of beans, but once you understand the basics, you'll have an easier time choosing the right beans.
What's right for you might be bad for someone else. It's a matter of taste, so let's first look at what you need to know about green beans and the taste of the coffee they produce!
The Beans’ Origin
Coffee beans are produced in various countries, each offering a distinct flavor profile. We can't go into details in this article (check out the origin articles on our blog for more detailed info), but here are some examples:
- Ethiopian beans are great if you want your coffee to have a bright acidity with fruity and floral notes.
- Colombian beans are a good choice for a balanced body with nutty and chocolatey flavors.
- Brazilian beans are ideal for a nutty, mild, and slightly sweet flavor.
Bean Varieties
Coffee beans come in different varieties, with the two main distinctions being Arabica and Robusta (often used for instant coffees or commercial coffee blends). Most home roasters prefer to use arabica beans as they have a delicate flavor and lovely aromas and are generally considered the gold standard for specialty coffee.
Arabica Bean Varieties
What you need to know is that there are many different varieties of arabica beans, which influences how they taste and how you roast them. There are the so-called "elephant beans", larger than the average coffee bean, and peaberry beans, which are a special type of coffee beans (round like a pea).
Robusta Beans
Robusta beans are, on average, more robust and bitter, with a higher caffeine content than your average arabica bean. They are often used as instant coffees or in espresso blends to improve crema and body. There are also a few different robusta varieties. If you want to give robusta beans a chance, try the Coffea Canephora var. Eugenioides variety, as this one is closely related to an arabica variety.
Processing Method
The processing method used to extract a green coffee bean from a coffee cherry is another important factor to consider when choosing your own coffee beans.
Washed Process
Washed coffee beans tend to have a cleaner and more consistent flavor profile with bright acidity. The potential for unwanted fermentation flavors is reduced because the fruit pulp and mucilage are removed during washing. This consistency is advantageous for roasters who want to highlight the origin flavors of the beans. In addition, washed beans generally roast more evenly because of their uniform moisture content.
Natural Process (Dry Process)
Natural process beans are dried with the fruit pulp intact. This can produce unique fruity and wine-like flavors. However, the presence of the fruit pulp can also lead to variations in moisture content within a batch. That’s why roasters need to monitor the roasting process carefully. This type of bean often requires careful roasting to prevent overdeveloped or baked flavors.
Honey Process (Pulped Natural)
Honey-processed beans are partially pulped. This means some of the fruit mucilage remains attached to the bean during the drying process. This processing method produces coffee with a balanced flavor profile that combines aspects of both washed and naturally processed beans. For this type of bean, a roaster must keep the residual sugars and absorbed moisture content from the mucilage in mind.
Semi-Washed (Wet-Hulled) Process
This processing method is generally used in Indonesian coffees and gives coffees earthy, herbal, and full-bodied flavors. The important thing for roasters is that the semi-washed process can result in beans with higher moisture content. This can influence the roast and requires adjustments to avoid uneven roasting.
Green Bean Selection Conclusion
We've examined some important factors influencing your decision about which green bean to choose. After all, it's not just about having the right roasting equipment; your beans are the key to brewing your ideal cup of coffee.
The origin of your beans is the first thing you should consider, as the origin is one of the main factors in the taste of the coffee you'll eventually brew. Once you decide on an origin, look at the different bean varieties you can find in that country (not all countries produce all types of coffee beans).
For most home users, Arabica beans are the number one choice. If you're new to roasting, it's probably a good idea not to immediately choose Elephant beans or peaberry beans unless you're willing to pay a lot of money for your experiment.
After choosing the origin and bean variety, look at the processing method. Washed beans are easiest to roast for beginners, while other processing methods result in beans that are a little more challenging to roast to perfection.
Ultimately, the choice depends on your taste buds, preferences, and preferred journey as a home coffee roaster.
Creating A Coffee Blend
If you've already roasted single-origin coffees, your next step is to experiment with creating coffee blends. You can either create your own unique, dream blend or try your hand at some of the classic blend recipes.
Each bean contributes a unique flavor to the mix in a coffee blend. Some beans are a perfect match and balance each other's acidity, add a fuller body, or create an interesting mix of flavor notes. That's one reason you'll often see robusta beans mixed with arabica beans. Robusta beans are pretty good at giving a blend a better body if you do it right.
So, how do you do it?
First, you need to know your beans. Understanding the flavor profiles of the beans you want to blend is important. You also need to ask yourself what your goal is. Are you aiming for a balanced cup, a complex flavor profile, or a specific taste experience? Your goal will guide your bean selection and blending approach. Blending is an art, and experimentation is key. Be prepared to try different bean combinations, ratios, and roasting profiles to find the perfect blend ratio.
Of course, you'll also need to decide whether to blend your coffee beans before or after roasting. There are pros and cons to both methods. Let's take a look.
Blending Before Roasting (Pre-Roast Blending)
For pre-roast blending, mix your green coffee beans before roasting them. This method allows you to create a blend with a unified flavor profile from the start.
A potential problem is that you might blend beans with different moisture content, density, and size. Some beans need longer roast times than others.
Unless you always use a 50/50 ratio in your blends, you'll also run into the problem of having differing amounts of different green beans. This can cause inventory issues.
Blending After Roasting (Post-Roast Blending)
For post-roast blending, you roast individual coffee bean batches separately and then blend them after reaching their desired roast level. This method gives you more control over each coffee's roast. Of course, this process is more time-consuming as you'll roast multiple times instead of just once.
Tips for Creating Coffee Blends
- Always keep detailed records of your blending experiments to re-create the perfect blend once you find it.
- Regularly taste your blends throughout the roasting and blending process. This will help you determine whether you need to make small adjustments.
- Don't be scared of experimenting. If you have a great idea or always thought, "I wish there were a coffee that tastes like…." then go ahead and try to create the blend. Creativity is just as important as understanding the beans you're using.
Popular Coffee Blends
Mocha Java Blend
Bean Ratio: A 1:1 ratio of Ethiopian Yirgacheffe and Indonesian Sumatra is typically used.
Best Roasting Level: Ethiopian Yirgacheffe as a light roast and Sumatra as a medium-dark roast.
Flavor Notes: This blend combines the bright acidity and floral notes of Ethiopian Yirgacheffe with the heavy body, earthiness, and spice of Sumatra. The result is a balanced cup with complex flavors, including fruity undertones, chocolate, and hints of spice.
Breakfast Blend
Bean Ratio: A 3:1 ratio of Central American beans to Colombian beans is typical.
Best Roasting Level: Central American and Colombian beans are roasted to a medium level.
Flavor Notes: A Breakfast Blend offers a balanced cup with moderate acidity, medium body, and a blend of flavors including citrus notes, nuttiness, and a mild, sweet finish. It's a versatile blend that pairs well with a morning meal.
Espresso Blend
Bean Ratio: The exact ratio can vary, but common components include Brazilian Santos, Sumatra Mandheling, and a small percentage of Ethiopian Yirgacheffe.
Best Roasting Level: Brazilian Santos and Sumatra Mandheling are roasted to medium-dark, while Ethiopian Yirgacheffe is kept as a light roast.
Flavor Notes: Espresso blends have bold and intense flavors. They often have a rather heavy body, low acidity, and a combination of dark chocolate, nutty, and smoky notes. The Ethiopian Yirgacheffe adds a touch of brightness and complexity.
Italian Roast
Bean Ratio: Typically, a blend of Central American beans and Indonesian Sumatra, with a higher percentage of Sumatra.
Best Roasting Level: Central American beans are roasted to a medium level, while Sumatra is taken to a dark roast.
Flavor Notes: Italian roast is known for its full body and deep, smoky flavors. It has hints of dark chocolate, roasted nuts, and earthy undertones. The dark roast level produces a rich, bold character with minimal acidity.
House Blend
Bean Ratio: The exact ratio varies by roaster but often includes a mix of beans such as Colombian, Brazilian, and African varieties. A common ratio is 3:2:1.
Best Roasting Level: Colombian and Brazilian beans are typically roasted to a medium level, while African beans can vary from light to medium.
Flavor Notes: House blends are designed to be crowd-pleasers. The goal is to create a balanced and approachable cup. These blends have a medium body, moderate acidity, and flavors like caramel, nuts, and a hint of fruitiness. It's essentially what you could call the "mainstream" blend.
Step 3: Determine Your Roast Profile
Once you have your roasting equipment and the green beans, it's time to decide on the profile you want to use for your own coffee roast. While there are no fixed rules on which bean to use for which roast level, some beans work very nicely with certain roast profiles.
Remember that some ways to roast coffee may need more or less time to roast beans, so the following roasting times are average.
If you've been confused about names like "City Roast" and "French Roast", this guide tells you which name applies to which roast level. So, let's check out which roast levels there are, how long they take, what type of flavor they produce, and which beans work well with that roast level.
Different Types Of Coffee Roasts
1. Light Roast (New England)
Estimated Roasting Time: 9-11 minutes
Flavor Characteristics: Light roasts have a bright acidity, delicate flavors, and pronounced origin characteristics. They often have floral, fruity, and tea-like notes with a light body.
Beans that work well as a light roast:
- Ethiopian Yirgacheffe
- Panama Geisha
- Kenyan AA
2. Light-Medium Roast (American Roast)
Estimated Roasting Time: 11-13 minutes
Flavor Characteristics: Light-medium roasts are a balanced blend of brightness and body. They retain some of the origin's complexity while introducing a hint of roasted sweetness.
Beans that work well as a light-medium roast:
- Costa Rican Tarrazu
- Colombian Supremo
- Guatemalan Antigua
3. Medium Roast (City Roast)
Estimated Roasting Time: 12-14 minutes
Flavor Characteristics: Medium roasts offer a well-rounded flavor profile with a balanced combination of acidity and body. They have notes of caramel, chocolate, and toasted nuts.
Beans that work well as a Medium Roast:
- Brazil Santos
- Sumatra Mandheling
- Mexican Chiapas
4. Medium-Dark Roast (Full City)
Estimated Roast Time: 14-16 minutes
Flavor Characteristics: Medium-dark roasts have a richer, fuller body with reduced acidity. They introduce pronounced roast flavors while maintaining some origin character.
Beans that work well as a medium-dark roast:
- Sumatra Lintong
- Java Arabica
- Tanzanian Peaberry
5. Dark Roast (Full City+)
Estimated Roast Time: 16-18 minutes
Flavor Characteristics: Dark roasts are rich, bold, and intense. They have a diminished acidity, and you can taste strong roast notes, e.g., dark chocolate, toasted nuts, and smokiness.
Beans that work well as a dark roast:
- French Roast Sumatra
- Italian Espresso Blend
- Dark Ethiopian Sidamo
Storing Roasted Coffee Beans
You'll unlikely use up all your roasted coffee beans right away. It's important to store them properly to preserve their freshness, aroma, and taste. Coffee is fairly delicate, so invest a small amount of money and time into finding and buying the right storage solution. Don't store your coffee beans in a plastic bag or food storage container.
An airtight container that is designed specifically for coffee storage is the best option. Plastic containers are the cheapest option, but not ideal. Pay a little more and invest in containers made from bamboo, ceramic, stainless steel, or silicone. Avoid transparent containers. The most important thing to consider is that your chosen storage container has one-way valves that allow gas from the beans to escape without letting air in.
In addition to using the correct storage option, you must keep coffee cool, preferably in a dark place and always away from direct sunlight and other heat sources. The room temperature is fine, but cooler is better. However, do not put your coffee beans into the fridge or freezer.
Don't forget to put the roast date on a label and stick it on the container. Ideally, using roasted beans within a month of their roast date would be best.
Home Coffee Roasting Tips
Here are a few tips and some things you must remember when roasting beans, no matter which equipment you use.
- Coffee beans shed some chaff during the roasting process. Always clean this up after the roasting process, and the equipment has cooled down enough to make it safe to handle.
- Use a colander to cool your coffee beans quickly. It’s best to do that above a surface that’s easy to clean, as more chaff will come off when you shake the colander (unless you’ve been using a coffee roasting method that takes care of most of the chaff, like a drum roaster).
- Keep detailed notes on your roasting process. Write down what you’re doing, even if the result isn’t what you wanted. This helps you to avoid repeating the same mistake in the future, and you’ll also have a list of successful attempts. This is especially important if you are experimenting with blend ratios.
- Coffee roasting is a skill with a learning curve. Don't be discouraged by initial mistakes; instead, view them as opportunities.
- If you're new to roasting, it's a good idea to start with smaller batches so you don't end up wasting too many beans if something goes wrong during your first attempts.
Mistakes to Avoid When Roasting Beans
- Inadequate Ventilation: Roasting coffee produces smoke and chaff. Avoid roasting in poorly ventilated spaces to prevent smoke buildup.
- Overloading the roaster with too many beans can lead to uneven roasting and inconsistent results.
- Failing to preheat your roaster properly can result in uneven roasting because the beans won't start roasting at the right temperature.
- Inattentiveness: Roasting requires your full attention. Avoid multitasking to prevent overroasting.
- Ignoring the first crack: The first crack is a critical milestone. If you miss it, you might not achieve the desired flavor.
- Cooling the beans too slowly can lead to over-roasting due to residual heat.
- Failing to maintain consistent heat or airflow during the roast can result in uneven or unpredictable outcomes.
- Improper storage can cause beans to lose flavor quickly.
- Not allowing roasted beans to rest can result in a flat or underdeveloped flavor in your brewed coffee.
- Not documenting your roast profiles and outcomes makes learning from your mistakes and improving your roasting skills challenging.
- Mindlessly following recipes: Starting with recipes can be helpful, but mindlessly following them can lead to suboptimal results.
- Inadequate safety precautions: Roasting coffee involves high temperatures. Ensure your roasting setup is safe, and take necessary precautions to avoid burns or fires.
Define Your Personal Roasting Style
We know that's a lot to take in, but the perfect cup of coffee is worth some effort, isn't it? Home roasting is an exciting hobby for the serious coffee lover, as long as you have suitable equipment and enough time to dedicate to it. Whether you choose a stovetop roaster, popcorn machine, oven, or invest in a drum roaster, each method has the potential to produce a great batch of coffee beans.
It might look like a pretty complex undertaking to get from the first step (choosing the right beans) to the last (storing your roasted beans properly), but it's worth it. While you can get good roasted coffee beans from coffee roasters who roast them after you order them, it still takes a few days for them to arrive at your doorstep. You'll always lose some of the freshness.
In addition to enjoying great, fresh coffee, becoming a home roaster will teach you more about the world of coffee than you've ever known. Now go and enjoy your coffee roasting journey, or visit more pages on our site to learn more about raw coffee beans, roasted beans, and more.