Benefits of Home Roasting
One of the biggest benefits of roasting your own coffee beans at home is the freshness. You control the source. You control the roast. You can even blend different beans to achieve a unique flavor. For a true coffee fan, roasting your own beans is the final solution to getting a perfect cup of coffee in the morning.
Roasting at home is more complicated than making instant coffee or, heaven forbid, drinking robusta beans. But if you’re reading this, chances are you are already a discerning coffee drinker. Maybe even an aficiando. Now it’s time to up your coffee game even more.
Evolution of a Coffee Roaster
My path to home roasting was a slippery slope. I drank bad Army coffee in my younger days. Then I learned that I could make better coffee using a French press than a percolator. A friend introduced me to grinding my own coffee beans, and I bought a blade grinder.
The blade grinder gave way to a burr grinder. I tried roasting my own coffee beans using my oven. Using a cast iron skillet on the stovetop. Using an old popcorn popper. Eventually I bought a drum roaster, and then a bigger drum roaster. That was a decade ago. I think I’ve gone as far as I can go, short of opening a commercial roasting business.
Roasting your own coffee can sound intimidating, but it’s not hard. I hope this post and this website help you to get started with this delicious hobby.
Is Home Roasting Expensive?
Roasting your own beans can be more expensive than buying commercially available coffee, at least initially. If you go crazy and buy a drum roaster and a burr grinder right off the bat, you’ll find coffee roasting to be a very expensive hobby. But it doesn’t have to be. You can roast and grind beans with materials you already have in your kitchen. You can slowly add better equipment later once you decide you like home roasting.
Ultimately, however, you will find that roasting your own beans can be cheaper than buying national brands. A pound of specialty coffee from a certain Seattle-based coffee company costs about $8-$9. A pound of unroasted, or green beans, can be as little as $5/pound. The coffee I buy is around $6/pound, even less if I buy in bulk. So buying unroasted beans and roasting at home saves me around $300 a year (yes, I know, I drink a lot of coffee).
Obviously, I’m not factoring in the cost of electricity or equipment, but over time you can save a lot of money by roasting at home and enjoy a better brew.
Find Green Coffee Beans
Unroasted coffee beans are also known as green coffee beans. You’re not going to find them in the grocery store. There are three ways to get green beans.
- Order from a local roaster. If you live in a major city, you probably have a specialty roaster or coffee shop nearby. If your coffee shop roasts its own beans, that means it has a supplier of unroasted beans. Stop in and ask the owner or manager if you can buy a pound or two of unroasted beans. Most roasters are passionate about their craft and will be happy to help you get started.
- Order online. Of course Amazon has unroasted beans and you can order through the website. But I recommend Sweet Maria’s, a supplier of green coffee and roasting equipment in Oakland, California. You’ll find their website easy to navigate with detailed descriptions of beans from around the world.
- Go to a coffee-producing country. This is a whole other level of obsessed. Still, if you happen to be traveling and find yourself in a coffee producing country, there’s no harm in trying to get some beans to bring home (remember to declare it to customs). I’ve picked up a few pounds of beans on trips to Vietnam and Guatemala and been very happy with the result.
How to Keep Beans Fresh
Roasted coffee loses its flavor after a week or two, and coffee grounds lose flavor every day. So how long can you keep unroasted beans?
Oxygen, heat, and moisture are the enemies of the beans. If you keep them in an airtight container out of direct sunlight, unroasted beans can last from one to two years. I buy in bulk (10-20 pounds) and store the beans in my pantry, roasting twice a week as needed.
Roasting Methods
Okay, now you have beans. How do you roast them? At its most basic, coffee roasting involves heating up the unroasted beans to around 425° F. This triggers several chemical changes which I’ll cover in more detail below. There are a variety of ways to do achieve this. Make sure you have a well ventilated area because roasting coffee generates smoke. Here are a few methods, moving from cheapest to most expensive.
The Oven Method
Set your oven to 500° F. This method works best with a perforated baking sheet. It’s important to have holes in the baking sheet to help circulate air around the beans. A good method is to spread aluminum foil on the baking sheet and poke additional holes in the foil using a toothpick. Place unroasted beans on the baking sheet and set in the oven. Remove from the oven once beans are at your desired roast level. Let beans cool and remove chaff. Warning, removing chaff is tedious.
Stovetop Method
You can roast coffee beans in a frying pan on your stovetop. Make sure you’re not using a pan with a non-stick coating. I prefer to use a cast iron skillet. Set the stove on medium high heat. Add a layer of beans and stir continuously until they are at your desired roast level. This method is cheap but takes a lot of practice to get it right. For a very detailed tutorial on roasting beans with a cast iron skillet, click here.
Air Roaster
Hot air popcorn poppers are a good way to roast beans. You will have to roast in small batches, usually 1/4 cup. Make sure your popper has vents in the sides of the roasting chamber. Some poppers blow hot air up from the center of the roasting chamber. This will cause the chaff to catch on fire. That’s bad.
To start, simply turn on the popper and add unroasted beans. It’s hard to hear the first crack over the noise of the popper, so you’ll have to observe closely. Remove beans once they’re done and cool them.
There are commercially available air poppers designed for coffee. They’re usually referred to as fluid-bed roasters. These can feature chaff collectors and roast profile controls. For a long time I used a roaster called the iRoast2. The iRoast2 is no longer made, but a similar model is the FreshRoast SR700
Drum Roaster
Drum roasters are the most expensive method of home roasting. Prices start around $400. But drum roasters come with larger capacity and much more control over the roasting process. A drum roaster has a mesh cylinder inside that holds the coffee beans. This roasting chamber spins continuously as hot air circulates to ensure an even roast.
Drum roasters feature chaff collectors and temperate and time controls. My personal favorite drum roaster, which I’ve been using for years, is the Behmor 1600.
If all of this sounds confusing, here’s a simple table with the pro’s and con’s of various home roasting methods.
| Method | Pro’s | Con’s |
| Oven | Cheap Easy to use | No chaff collection |
| Stovetop | Cheap | Difficult to master Uneven roasts Generates smoke |
| Hot air popper | Low cost ($20) Easy to use | Small quantities Difficult to hear first crack No temperature control |
| Fluid bed | Easy to use Chaff collector Temperature control | Medium cost ($100-200) |
| Drum roaster | Easy to use Large batches Temperature controls Chaff collector | Expensive ($400 and up) |
What’s a Roast Profile?
As you get into home coffee roasting, you’ll hear about roast profiles. A roast profile is simply what happens to the beans during the roasting process. Some roasters allow you to change the temperature throughout the roasting cycle, and you can find formulas and profiles online for this.
A roast profile allows a roaster to achieve the same level of taste consistently with roasts. My perspective on this is that this is a subject more interesting to commercial roasters than home roasters.
I used to tinker with roast profiles a lot. You can fall pretty far down the rabbit hole on this one. I’ve even known roasters who attached voltmeters to their roasters to measure the power levels from the outlet. I wouldn’t worry about roast profiles if you’re starting out. Just roast your beans and enjoy your coffee.
Stages of Coffee Roasting
Roasting has more effect on your coffee’s flavor than any other variable in the coffee process. A good roast can make a mediocre bean taste great and make an expensive bean taste horrible. So a solid understanding of the stages of coffee roasting is key for hobby enthusiasts and professional roasters alike. Here are the stages of coffee roasting, which apply no matter what roasting method you’re using.
Drying
When you start the coffee roasting process, the beans slowly start to dry out and lose their moisture. They will turn from the olive green color they are as raw beans to a pale yellow, and then begin to brown. The moisture inside the beans evaporates into steam as the beans past water’s boiling point (212° F). This steam can smell like bread.
First Crack
At this stage, the coffee beans continue to heat up. They begin to pop, with a crackling sound like popcorn. This is often referred to as the “first crack,” and it indicates the beans are around 375° F. The beans are now lightly roasted – sometimes known as a cinnamon roast because of the cinnamon-color of the beans. You could stop the roasting process at this point and grind the beans for drinking. But let’s assume you keep going.
Medium Roast
After the first crack, the beans continue to expand. The crack allows them to swell to almost double the size of a green bean in this process. The coffee beans throw off chaff, a thin husk similar to the inner husk of a peanut. Most roasters have a chaff collector, but you’ll have to separate the chaff by hand if you’re roasting in a pan or on a baking sheet.
The beans are around 425° F now. There’s a lot of smoke generated from the roasting process. The internal sugars of the bean begin to caramelize and the beans will smell like coffee. You have to watch carefully at this point, because the beans will begin to change quickly.
Second Crack
At the second crack stage, seconds can mean the difference between a rich, dark roast and a burnt mess. The beans will make a popping noise again, fainter than the first crack. Their temperature is around 440° F. There’ll be a lot more smoke. The fats within the beans will liquefy and rise to the surface, resulting in an oily sheen.
Cooling
Once your beans are as dark as you desire, start the cooling phase. For beans roasted in the oven or on a stovetop, this means removing them from the heat source. You may want to fan them as well until they’re cool. Do not handle the beans while they’re hot – you will get burned. Most home roasters have a cooling stage which cools the beans automatically.
Resting
You can grind and brew coffee beans once they’re cool, but I recommend letting the beans rest for a few hours or even a day. I typically roast in the evening and then grind and brew the next morning. Letting the beans rest allows them to discharge the carbon dioxide gas generated during the roasting process and evens out the flavor profile of the beans.
Enjoy!
Store your beans in an airtight container and enjoy a cup of freshly roasted coffee!
Common Roast Names
Newcomers to coffee roasting may be confused by the names associated with different levels of roasting. I’ve included the table below with common roast level terms. Just realize that these terms are HIGHLY subjective. One person’s City is another’s City Plus or even Full City. Different beans roasted to the same level will also taste different. It’s all a matter of your preference, so don’t get too wrapped up in the labels. Just enjoy your coffee.
| Stages of Coffee Roasting | Common Roast Names |
| First Crack | Cinnamon |
| City Roast | |
| Medium Roast | City Plus |
| Full City | |
| Second Crack | Full City Plus |
| Vienna | |
| French |