How to Roast Coffee Beans at Home

by Atypical Sapien

Note from Daisy:  When I saw this incredibly useful post over in the forum, I knew I had to share with you guys for two reasons: first, to show you how awesome our forum is and secondly, to provide this fantastic information.

For those of you who will go postal without would really miss a cup of coffee after an SHTF event, the best way to stock up it is with green, unroasted coffee beans. (You can get green coffee beans packed for the longterm in cans with a 20-year shelf life here.)

But the thing to know about green coffee beans is that you cannot brew coffee with them until you roast them. Here’s an awesome primer, posted with permission, on how to roast coffee beans at home to get you started.

How to Roast Coffee Beans at Home

There are numerous advantages to home roasting. You make the coffee that you want, the cost is much less, green beans last for a long time, (some say for years if properly stored) whereas roasted beans start deteriorating in flavor within a week or so regardless of how it is stored. Home-roasted coffee makes good gifts, too.

If you start looking around you will find many opinions on how to roast your own coffee beans. This is how I do it.

The Beans

I get my beans from Sweet Maria’s. They have many varieties and a plethora of information on roasting. Beans are available from South America, Central America, Africa, Indonesia, South-East Asia, and a few other regions. I have tried many.

My palette is not refined enough to be able to differentiate the subtleties in the cupping descriptions. Most descriptions read like pedantic wine snob’s oenological lexicon. Here is a description of a Burundi Kayanza Nemba Station – Wet Process Bean with a cupping score of 87.9 – it costs $4.77 if you purchase at least 20 pounds. (gotta add shipping) “Tea-like characteristics flourish in the brew, Oolong and black teas, along with baking spice and a juicy lemon note. Acidity is brilliant, like citrus and the tannic side of black tea, and Nemba’s finish is quite clean.” City to Full City.

Even though I prefer a light City to Full City roast, I do have a few varieties that list as being good for espresso. There is a 95-year young lady at my church who loves dark roast. I usually keep her supplied.

Sweet Maria’s would be my recommendation for your first stop in roasting. You may want to start with one of their sample bags. I also purchased a book on home roasting from them. ( I probably should get a kickback for recommending them since I have sent many to their site.  I don’t get a kickback, but I should.)

The Equipment You Need for Roasting Coffee Beans

My first few pounds were roasted in a toaster oven. I currently use a Victorio popcorn popper that I purchased from….Sweet Maria’s. (You can find that popper here, too.) It is designed with coffee roasters in mind. Skip the cheaper $25 aluminum popcorn poppers. The gears are plastic and it is aluminum.

You will find many options on roasting including air popcorn poppers – I started with this. Air poppers can only roast about ½ a cup at a time, and the paper-like chaff that is on the green beans blows all over the place which makes a mess.

I am considering upgrading to a Behmor this winter.

You also need:

• Outdoor grill with cooking burner
• One frozen plastic cooler pack wrapped in foil
• One large glass mixing bowl
• Oven mitt, air mattress air pump
• Beer
• Bluetooth speaker

About once a week or so I go through my bean stash and select four cups of beans. Sometimes I mix the varieties, sometimes not.

1. With the grill on high, preheat the popper. There is no particular time, though some say that it should get to 475 degrees. I usually put it on the grill, forget something, go in the house and then come back and pour the beans in the roaster. I roast a maximum of two cups of beans at a time – anything more than two cups and the roast range will vary from burnt to light roast.
2. It usually about the length of a song (this is why you need the Bluetooth) for the beans to start the first crack – that is the official term. Grill temperature, wind, humidity, and beans are all variables. You’ll hear it. It’s a little popping sound, much like popcorn, but not exactly.
3. I don’t stop stirring the pot as long as the beans are in it. It doesn’t take long for them to scorch. It also doesn’t take long for them to over-cook. The more times you roast the more you get familiar with the subtle smells and sounds of roasting. Since I like a lighter roast ( City to Full City) I usually default to taking them out when the cracking sounds start to get fairly vigorous. It’s just a few minutes between the first crack and the time the beans are ready. You can see the color change. It also doesn’t take but a few minutes to go from light roast to french roast ( black oily beans) to oh crap, I just ruined a batch.
4. As soon as the beans have reached the desired cook time and brownness level, I dump them into a bowl with one of the freezer packs in it. A quick cool down time on the beans is as important as the roast time. Slow cool downs make the roast bitter.
5. I usually do a second batch and once I have dumped those beans into a bowl, I use the air mattress blower with the tiny little nozzle to cool down the beans and also to blow off the paper-like chaff that encases all beans.

I like to leave the beans out in a bowl overnight. It smells good and the roasted beans need to off-gas. Most of the time I will go ahead and grind the beans in a blade grinder- this is an absolute no-no according to the book I mentioned above. The “experts” say that the blade grinders heat the beans and affect the flavor. I have also invested in a few $50 burr grinders which work fine on darker roasts but the light, harder roasts just confuse the cheap-ish grinders. I’m not too enthused about investing a few hundred bucks into a grinder when I can’t taste the difference.

I do sieve the beans and re-grind. After the sieving process, the ground coffee goes into a loose lid jar. I also use a standard drip coffee pot with a metal mesh filter. Some coffee snobs’ heads would now be exploding if they read this.

Last notes

You’ll also find that the hard-core roasters are picky about the grind size, the brew method, bean origins, temperature, almost anything to do with coffee for that matter. I have seen people who will invest thousands of dollars into a roaster, others who roast in a frying pan on the stove, in a metal dog bowl with a hot air gun, and others who use an electric bread machine.

I would recommend that you just have fun with it, learn a bit and don’t waste a whole bunch of money finding out that home roasting coffee not your “cup of tea”. Sorry, I couldn’t resist that one.