How to Roast Coffee Beans at Home, and Why Do It

How to Roast Coffee Beans at Home I love home coffee roasting, and I’d do it on a regular basis if I had the time. But time for me is the most expensive commodity, so I need to manage it carefully. Because of that, I have to rely on coffee roasters for my brewing needs. Anyway, I needed some specially roasted beans for my cold brew concoction, and no roasters seemed to have anything close to my needs. I dusted off my coffee roasting skills and proceeded with the task at hand.

Why Roast Coffee at Home?

There are a few great reasons to roast your own coffee, and it’s not that complicated, nor does it take too long to do it. And if your time is not too tight, you will definitely enjoy doing it on a regular basis.

  • Firstly, coffee-beans-roasting is fun and easy. You will enjoy doing it every single time, even if you get a bad batch.
  • By roasting yourself you only roast small batches, for a few days, so you always have freshly roasted beans. It doesn’t get any fresher than that.
  • It is cheaper to buy green beans, and even if count the energy cost, you still save some money. In the world of specialty coffee though, the cost of beans, is the most affordable expense, if you are not into kopi luwak.
  • Another great advantage, and what got me to roast this time, is the ability to make your own blend, and roast it the way you like it, (or very close to it, I’ll show you in a minute why).

Light roasted coffee beans

I personally needed a special blend, light roast for my cold brew, hence the need to roast my own. I wrote an article about how to choose a blend for cold brew here. I couldn’t find any blend that suited my needs, hence my recent roasting adventure.

Coffee Roasting Equipment – What Are the Options?

Even though roasting is the least expensive process of making a cup of joe, it is not very popular. We rely on roasters to do it for us, and we rarely consider the option to do it at home. Here are the options.

  • The least expensive method is to use a skillet. A cast iron skillet or pan will do the trick.
  • Roast them in the oven. It’s more difficult to guess when they are ready, because you can’t see inside, and can’t hear the crackling sounds, but it works.
  • The next inexpensive method is to use an air popcorn popper. The best ones are the ones that blow the hot air from the sides, and not through the center.
  • If you are really serious about this, and you want to take the job to perfection, use a specialized coffee roaster. The special coffee roasting equipment will help you get consistent results, and predictable roasting degrees. Obviously, the perfection comes with a price, that price is a couple of hundred dollars at least.

How to Roast Coffee in a Skillet

How to Roast Coffee Beans at HomeThis is the simplest method, and the cheapest, however, you need to practice in order to get consistent results. Make sure you use a heat diffuser if you have an electric stove burner. Here is how you do it.

  • You need a good range hood, otherwise, you’ll set off the smoke detector, and your house will full of smoke. If you don’t have a good range hood, you will need a portable stove, and you should take this outside.
  • Set all the equipment around the stove within reach.
  • Turn on your hood range, and open all of your windows.
  • Prepare about ½ to 1 cup of beans. If you are learning, start with smaller batches, to get more chances to exercise this.
  • Use a heat diffuser, and set the stove to about 500F. Preheat your skillet.
  • Pour the beans in the skillet and start stirring continuously.
  • The beans will slowly change color, as you roast them, changing from green to yellow, light brown, and dark brown.
  • After about 5 minutes, the beans turn from golden to brown, and you will hear the first crack. At this point the beans are ready and this is a light roast. If you like a light roast, stop the roasting now and proceed with cooling.
  • From this point on beans can be used to make coffee. It’s your taste, and you decide how dark you want the roast. For me, a light roast is fantastic, depending on the origin.
  • For darker roasts, you need to continue roasting, and the beans will just darken more an more. When the beans become dark brown it’s time for the second crack. When you hear that, you can stop the roasting, you have a dark roast.
  • If you really need to, you can do a Spanish roast, which requires roasting beyond the second crack.
  • Take the skillet off the burner, and transfer the beans into a metal colander to cool them off immediately.
  • While you are cooling the beans, all of the chaff will separate from the beans, and it could be a little messy. I do it outside.
  • The beans will continue to “roast” a little during the cooling process, so using two colanders and transfer the beans back and forth between the two, helps cooling.
  • Allow the coffee beans to de-gas overnight, then store in an airtight container. Stored in the proper container, beans will stay fresh for about a week or a bit longer. Enjoy!

How to Roast Coffee Beans in a Wok Video

How to Roast Coffee Beans in a Wok

Where to Buy Green Beans?

One of the best sources of green beans in the US is Sweet Maria’s. They have a great selection, sourcing from the entire world. I have bought from them many times, and have never been disappointed.

Green Coffee Beans BagIf you live in Canada, a great source is the B.C. based company,  U-Roast-It Coffee. I needed some good quality beans for my cold brew blend, and their Organic Mexican Green Beans-Chiapas Siltepec was exactly what I needed. Their Mexican beans are nutty with chocolate notes and medium acidity. They also have some other green single origins and an espresso blend.

How to Roast Coffee Beans with a Popcorn Popper

When picking up a popcorn maker for roasting coffee, you need to make sure it’s one of those with the air coming from the sides at the bottom of the unit. The machines with a screen at the bottom are not great because they don’t move beans properly and the air flow can be stopped easier than with the other types.

  • Set up the popper in a ventilated place, for instance under the range hood, or just outside. This produces a lot of smoke, and it will set off your smoke detector.
  • Proper light is also required; this is how you see the roasting degree during the process.
  • Roasting Coffee with a Popcorn PopperPut a large bowl close to the popper just under the chute to collect the chaff. Use a wet towel or a wet napkin to line the bottom of the bowl. This is how you capture the chaff when you are roasting. If you are roasting outside you don’t need that.
  • I found that using a long extension cord lowers the power in the popper, hence slows down the roasting. I like to roast my beans slower, because I have better control over the roasting degree, and the flavors are better.
  • Turn the air popper on and start pouring the green coffee into the chamber. With low quantities, the beans spin because of the hot air coming from the side vents. Stop pouring when the beans are barely moving. Depending on the size of your popper this should be around ½ to 2/3 cups or less. This is the correct amount for a batch roasted in an air popper.
  • Put the cover on to maintain the correct temperature.
  • Have a timer handy, and heighten your senses. Be prepared to get visual and acoustic cues, but the smell will help a bit there too. The timer will tell you when to start to monitor very closely.
  • At about 30 seconds you will see the chaff starting to move up, and float.
  • After 1minute and 30 seconds, the beans will start to move faster in the popper, as they lose the water, and they are lighter.
  • Between 2:30 and 3:00 minutes you will hear the first crack. You have a light roast. You can brew a great cup with these beans. If you want a darker roast you should continue on.
  • Around 4:30 to 5:00 there will be the second crack. Beyond this point, you will have dark roasts. I don’t recommend you roast dark with a popcorn popper, as the roast is too fast and it is not appropriate for dark roasts. Your coffee will smell and taste like smoke.
  • Cool the coffee down as shown earlier in the article.
  • Leave coffee to degas for 12 to 24 hours.

These numbers are for my popcorn popper and without a power extension. If you use an extension, you can slow down the roasting considerably. I strongly recommend you to use one too.

Safety hazard: When roasting coffee with a popcorn popper, never leave the machine unattended while roasting. Coffee beans can burn easily if they are roasted beyond a certain point. The popcorn machine is not intended for roasting beans, and if you use it for that, you will lose the warranty.

How to Roast Coffee Beans at Home Using a Popcorn Popper

Coffee Roasting Tutorial: The Popcorn Popper Method

Roasting Coffee Beans with a Home Roasting Machine

The best method to roast at home is to use specialized equipment. Domestic use roasting appliances range between $150 and $500. You can also use commercial equipment to roast at home if you can afford it, but in my opinion, it’s not worth. I don’t own a coffee roasting machine, but I used one before, and it makes a big difference. I only roast occasionally, so for me, it’s not worth the initial investment. If you want to roast your beans on a regular basis, a home roaster is essential.

A specialized appliance will allow you to control the temperature, and the fan speed, to do larger batches, and they have timers. They are safer to use in general, because of the timer, and they ensure an even roasting.

Behmor 1600 Plus Customizable Drum Coffee Roaster

Behmor 1600 Plus is a countertop coffee roaster that can process up to 1 pound of greens at a time. Here are a few facts about it:

  • It has five roast profile settings, but you can also roast manually for an artisanal batch.
  • The interior is lighted to let you easily inspect the beans during roasting.
  • The roasting elements are controlled by a quartz unit.
  • The unit has advanced smoke suppression technology which makes it great for indoor roasting.
  • Efficient cooling cycle; easy chaff separation with removable chaff tray and drum for simple clean up
  • 1-year warranty

Video – DIY Coffee Roasting with the Behmor Drum Roaster

DIY Coffee Roasting with the Behmor Drum Roaster

1 – Image By Dan Bollinger – Own work.

Photo of author

Dorian Bodnariuc

My name is Dorian and I am a former barista. I consume coffee in any form, as a beverage, in savory recipes and desserts. My favorite caffeinated beverage is the espresso. I love to share my coffee brewing knowledge and my geeky coffee research. This blog is one of the places I write about coffee. More about Dorian... If you want to learn more about this site and how I started it, check our About Me page, where I explain all about it.