Roast coffee popper
Disclaimer, Roasting coffee is dangerous, only highly trained and skilled people should ever attempt this magical feat.  Cautions;  Heat, fire, electricity, forced air heating, debris blowing around, and human nature. 

Do this at your own risk. For educational purposes only.
An easy way to get started roasting coffee at home that produces even roasts from the City to the Vienna roast levels. A City roast is a light roast level, a Full City roast is a medium level roast and a Vienna roast is dark black and oily, very much like you would expect from a large commercial roasting operation. 

The beauty of roasting your own coffee is finding a roast level that tastes best to you. Every variety of coffee tastes better at different roast levels, the journey begins here. Everyone tastes things differently & sorting out the different flavors inside of a cup of coffee takes some time to develop. Expert tasters are known in the coffee world as cupper’s. Most green coffees are sold with cuppers’ notes and I try to taste what the cupper has found within that particular lot of coffee. I don’t always find the exact flavors they found, but I can usually find a roast level that gets me pretty close.
You might be lucky enough to already have a used popper at home or you can find them in many thrift stores for under $5. Stock poppers roast quickly and usually only 3 to 4 ounces at a time. It’s not a big deal… roast just enough coffee to meet your weekly needs . The idea is to drink freshly roasted coffee, not storing pounds of roasted coffee. Which, by the way, is going to seem ludicris to you after you develop the newly aquired taste for fresh roast.
Many of the items that you will need to get started are more than likely already in your home: A hot air popcorn popper like the Popcorn Pumper or the West Bend Poppery 2 design are the most common models that you will find out there. There are many different models of popcorn poppers out there, and people have been able to convert many of them into great little coffee roasters. For the purpose of this demonstration, we will be using the Poppery 2 types. We will be roasting outdoors or, more than likely, out on the back deck. We will also need a chimney, a big wooden spoon, a metal mesh colander or 2 for cooling, and a pair of leather gloves. 

A stop watch is a very useful tool, you can roast more consistently by monitoring the times when you start (the roaster), the drying phase (green beans turn yellow and the moisture is displaced). The start of 1st Crack, the length of 1st Crack and the time between the end of 1st Crack to the beginning snaps of Second Crack or 2C. You might want a very dark roast, and taking it to 15 seconds of rolling 2C (snaps continually and very smoky) is as dark as you are going to want to go. 

The chimney can be as simple as a discarded soup can with both ends removed, as long as it fits snuggly inside of the roasting chamber. You can measure this out precisely, or you can take the popper to Walmart @ 2 am and find one that fits perfectly. I like to use a glass hurricane chimney the bulge makes a perfectly extended roast chamber. It will not fit snuggly, and you have to wear a pair of leather gloves to quickly remove it, before you dump (end) the roast.With the soup can type, you will be looking directly down into the roast (with flying bits of paper and other debris), you should wear safety glasses. I like the glass; you can see the progression of the roast from the side, avoiding the UFO’s altogether.

Some people use the plastic hood setup that comes with the popper, I do not. Roasting popcorn in a popcorn maker for 5 minutes will rarely melt the hood, as the roasting temperature range is lower, than for coffee. Roasting coffee requires a bit more heat & a longer roasting time. Eventually the plastic will melt, and induce undesirable effects in your cup of coffee. You want to avoid introducing smoking plastic erroneously into your coffee. Don’t keep it. Toss that sucker into your plastic recycling bin, and forget about it.
Alright, if you are still with me, than here we go!
Basic Instructions:
Set up the popper in a well ventilated place (outdoors is best). Roasting coffee produces smoke, and smoking is not good for you (in mass quantities, that is… a little bit never hurt anyone ;-) Like former president Bill Clinton, you want to smell the smoke, but not inhale it. ;-)

You also need a strong light (the sun) so you can look down into the popper chamber to accurately judge the roast as it progresses. Try to have your supplies within reach. 

Accurately measure out some coffee beans. Once you identify the right amount, you will want consistency out the next few batches. I use a digital scale and weigh out each roast. You may use the volume method, if you don’t have a digital scale. Mechanical scales tend to be very inaccurate.

 For a stock West Bend Poppery II, 4 oz. is the maximum, or 2/3 to 3/4 cup. There is a very good trick for figuring out the batch size: with the popper running, add green coffee until the mass of beans just stops swirling. As the roast progresses and the beans lose mass, the beans will begin swirling. Working very quickly (within 60 seconds), dump, weigh out, or measure the amount in a measuring cup. This is your particular poppers upper limit. If it comes to say for example 4 oz, then you should try 3.5 oz in your 1st test batch. If it takes too long to reach 2nd crack (anything over 16 minutes in a popper is baking the beans and it tastes flat, dull, and lifeless) then you need to increase the load to 3.75 oz on your next batch. If your results are good, then you write down and remember what you did to get there. Keep a simple notebook around, and log in your findings.

Add in the beans, insert the chimney and plug in your popper (Start time on watch). They should be swirling around and gradually picking up speed as the beans begin to dry out. Use a stopwatch to keep track of times, but for now just watch and observe.

With the machine running, watch for smoke and the "first crack" of the beans at about 3 minutes. It’s going to smoke pretty good…do not panic…wait another minute, monitor the beans closely for desired roast color, smelling the smoke and listening to the crackling. On your 1st trial batch, you will want to experience both 1st and 2nd cracks. There are a lot of things that are going on during this phase of roasting, but they are unimportant right now, you need to just focus on the roasting process. Once you get the hang of things, we can talk about the Why. We want to make sure that your roaster is capable of producing a Full City + roast level. If all is well, at that point, we can learn some tricks to slow down the roasting process to improve the flavor of the roast.

Total time for a lighter roast should be around 5 minutes (end of 1C), full city roast around 6 minutes (a few snaps into 2C), and darker roasts (20 seconds into 2C) closer to 7.5 minutes. Roasts can develop quickly, so stay on top of things. Don’t get distracted by the cell phone, barking dogs or screaming kids. Focus on the roast process, (think of roasting as ‘ME’ time ;-)

Dump the beans out when they are a bit lighter than the color you are targeting. You want to stop the roasting process as quickly as possible. The roasting process continues until beans are cooled down to 200F or so, keep the beans moving to cool them quickly.  The final roasting temps can be as high as 460F, (paper burns @ 454F) for a dark roast. You should be wearing those leather gloves, until things cool off. If you have 2 metal colanders then you can transfer the beans back and forth to cool them off rather quickly.
Fluid-bed coffee roasters are highly sensitive to both ambient temperature (the room temperature and electrical line voltage. Later on, as you progress with your roasting skills, you can learn how to use both to your advantage, speeding up or mainly slowing down the total roast time length.

Freshly roasted coffee should be stored out of direct light (and not in the refrigerator or freezer) in an airtight glass jar. Wait 12 to 18 hours after roasting to seal the jar tightly; as the coffee needs to release Carbon Di-Oxide (same stuff as in beer, completely harmless in low doses). 

Your coffee smells great right out of the roaster; however it obtains its peak flavors 4 to 24 hours after roasting. I’ll call it fresh for 5 days, after that it will degrade somewhat for another 5 days. 2 to 3 weeks later, you will start noticing staleness and it won’t taste ‘right’ to you anymore. Better to give it to your friends or co-workers (It’s going to be unbelievably fresh to them) as they will appreciate the free coffee and still wholly enjoy it. You are now a certified coffee snob, and only the best will do ;-)

Welcome aboard! The trip is about to begin! 


1 Add in beans (pre-measured), insert chimney, plug in popper and start timer.

2 Observe the drying phase; ensure that the beans are constantly moving.

3 When 1C is about to start; observe the chaff blowing off the beans and the increase in smoke.

4 Check time when you hear 1C start, and note when 1c ends.

5 Time the delay between 1C and 2C. Put your gloves on!!!

6 Smoke will get thicker; darker chaff will fly just before 2C starts.

7 When you hear 2C start, unplug popper, remove chimney, and dump beans into colander. (Stop Timer on watch) Work quickly, and remember to watch out for hot stuff!

8 Keep the beans moving with a wooden spoon, or by dumping back and forth between 2 colanders. Once they are cool enough to touch comfortably, you can relax a little bit.

9 Let everything cool down for about 15 minutes, then get another batch going.

10 keep the individual batches in separate containers, find a roast color chart (Sweet Maria’s has a nice one on their website). Compare your roasts to the chart.

11 Wait at least 12 hours before grinding and brewing.

Great sites to check out:

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