Foo - KT1000 Coffee Roaster

As some of you may know, I've recently decided to take the 1st step in the coffee roasting arena...or as I like to say, "the next step in my coffee evolution".

I bought a hot air (popcorn) popper. This is the entry level way of roasting coffee (e.g. not getting the $400 home coffee roaster). I read a lot of tutorials to make sure I got the right type of popper (only a certain kind work correctly for roasting coffee).

Ok, here is how it all went down.


First, I had bought an 8 lb. sampler box of green (unroasted) coffee beans from Sweet Marias (suggested place to start by Mill Creek). I picked one of them to start with (Kenya AB).

I had decided to roast on Thursday because I don't drink much coffee at home on weekdays as I'm up and off to work quickly, and you have to let the coffee rest (dissipate CO2) for about 12-24 hours after roasting before using. So Thursday was the perfect night to roast just enough coffee for the weekend (as the whole idea is to always have very freshly roasted beans).


So I grab the first bag to start. I start the first batch (can hold about 1/2 cup). The tutorial I was going by said you would hear the first crack at around 3 minutes and the second crack at around 4 minutes. First crack would be about 'light city" roast and 2nd crack would be about "full city" roast. Longer than that and you get the dark roasts.

I like my coffee around 'full city', so I planned on 4 minutes for the 2nd crack. The problem? I heard a few cracks around 1:30. Not having roasted before, I thought maybe it was a 'false crack' because it was waaaay too early.

Any way, to make a long story short, this popper is apparently hotter/faster than the one they used in their tutorial. That first batch was over roasted. They were so dark they looked like Starbucks beans (bleh!).

So I started the second batch and learned another quick lesson. You need to let the popper cool down between batches because the first beans that go in (ones in bottom) get roasted very fast because of the heat already there (hot metal reservoir). The second batch looked very "salt and pepper" with some really dark over roasted beans and some light. Chucked that batch.

By this time I thought I kinda of had the mechanics down and it was only getting the timing right. Third batch came out good. First crack was at about 1:30, second crack is around 2:45. I found the level I like my roast was good at about 3:30-4:00. (Tutorial was estimating 5-7 minutes).

Now, armed with the formula I roasted the rest of that bag. When all was done, I got about 1/2 lb of roasted beans (from the 1lb bag). I lost about 1/2 lb due to those two bad batches and spilling some a few times while cooling in a colander.

You aren't supposed to use them for at least about 12 hours, so tonight will be the actual tasting. If interested, I may take a picture of the roasted beans to show you.

BTW, it's a pretty messy process. The beans release their chafe as they roast and it goes everywhere. It doesn't just come neatly out of the popper chute and into the bowl/sink like you want. It ends up going all over the area where you are roasting.

Sounds like too much work for a cup of coffee, but I used to make a mess of my whole kitchen while brewing up a batch of beer.
I guess if it's for something you like, and it's better than what you can find in your average shop, then it's worth the effort. I'm interested to hear how it turns out.

Your roasting times are a bit fast. A good and easy way to slow down the roast times somewhat is to plug the popper into a heavy-gauge extension cord. Please post some pictures of the coffee so we can take a gander.

http://www.ineedcoffee.com/01/popper/

http://coffeegeek.com/guides/popperroasting

http://www.robinchew.com/coffee/roasting_guide.html

http://www.instructables.com/id/$11-Popcorn-Popper-Coffee-Roaster/

http://www.thecoffeefaq.com/5homeroasting.html

http://perk-o-late.com/2007/10/10/roasting-coffee-in-a-popcorn-popper/

http://www.gourmetcoffeeshop.net/home-coffee-roasting.htm

http://www.swanfarms.com/FoodBlog/?p=371


Here are some helpful links on using a hot air popcorn popper.

http://www.ineedcoffee.com/01/popper/

http://coffeegeek.com/guides/popperroasting

http://www.robinchew.com/coffee/roasting_guide.html

http://www.instructables.com/id/$11-Popcorn-Popper-Coffee-Roaster/

http://www.thecoffeefaq.com/5homeroasting.html

http://perk-o-late.com/2007/10/10/roasting-coffee-in-a-popcorn-popper/

http://www.gourmetcoffeeshop.net/home-coffee-roasting.htm

http://www.swanfarms.com/FoodBlog/?p=371


Here are some helpful links on using a hot air popcorn popper.
The coffee geek link (2nd one) is the one I was mostly going by.

Sounds like too much work for a cup of coffee, but I used to make a mess of my whole kitchen while brewing up a batch of beer.
I guess if it's for something you like, and it's better than what you can find in your average shop, then it's worth the effort. I'm interested to hear how it turns out.

As both a homebrewer and coffee roaster, it is hard to go back to the commercial marketplace after you have made your own. Because Ms. MillCreek and I are more into red wine these days, I have stopped homebrewing, since she does not drink beer and I could not finish a 5 gallon batch before things went bad.

But since we both drink a lot of coffee (espresso, drip and French press), the cost savings, freshness, quality and ease of preparation will keep me roasting my own for a very long time.

I had decided to roast on Thursday because I don't drink much coffee at home on weekdays as I'm up and off to work quickly, and you have to let the coffee rest (dissipate CO2) for about 12-24 hours after roasting before using.

Really? So those 19th C literary allusions to roasting beans on the campfire and then brewing away are... steering toward the suboptimal? live and learn...

ps-> so what is the price of green beans?

But since we both drink a lot of coffee (espresso, drip and French press), the cost savings, freshness, quality and ease of preparation will keep me roasting my own for a very long time.And considering the "roaster" investment was only $13....overall, it should save some decent money when I get get "good coffee beans" in the $5/lb range.

ps-> so what is the price of green beans?

Here is a product list from Sweet Marias, where I bought mine.
http://www.sweetmarias.com/prod.greencoffee.mvc.php

Overall, you can get good beans for roughly $4-6/lb. The beans that would probably cost you twice that (or more) to buy roasted and a month old.

Really? So those 19th C literary allusions to roasting beans on the campfire and then brewing away are... steering toward the suboptimal? live and learn...


Yes. Generally speaking, fresh roasted coffee tastes best if allowed to rest for 24-48 hours after roasting. As a general rule of thumb, green coffee beans cost approximately half the cost of the same beans roasted. For the type of green coffee buying that I do, through a co-op, I am generally paying about $ 3-4 per pound delivered, but I am buying beans by the 10-15 pound batch. Most of the commercial green coffee vendors are somewhat more than this.

Sounds like too much work for a cup of coffee, but I used to make a mess of my whole kitchen while brewing up a batch of beer.
I guess if it's for something you like, and it's better than what you can find in your average shop, then it's worth the effort. I'm interested to hear how it turns out.

To each their own. You've been around me enough to know how little (never) I drink beer and how crazy I am about my coffee. :)

Here is a product list from Sweet Marias, where I bought mine.
http://www.sweetmarias.com/prod.greencoffee.mvc.php

Overall, you can get good beans for roughly $4-6/lb. The beans that would probably cost you twice that (or more) to buy roasted and a month old.

Hmm... Yemen ~$6-8, Ethiopia ~$6, that is about half. And Yemen is only patchily available at the place I hit here.

Definitely something to think about.

I wonder if you can get Haitian coffee green. Can't get it roasted, really, either, but when I could get it, it was my fave. Been a lot of years now.

Hmm... Yemen ~$6-8, Ethiopia ~$6, that is about half. And Yemen is only patchily available at the place I hit here.

Definitely something to think about.

I wonder if you can get Haitian coffee green. Can't get it roasted, really, either, but when I could get it, it was my fave. Been a lot of years now.

I remember you talking about the Haitian one before. If you come across it, link me to it so I can try it too. :thumb:

KT, sounds like you are well on your way to some delicious coffee! Plus, roasting lightly, and drinking the coffee shortly after roasting (couple days) is the best way to maximize the caffeine output of the bean :thumb:

I am curious, though if it matters if the bean is roasted quickly (at a high temp) or not, so long as you harvest it from the roaster at the desired pop. I've only used a pro-grade roaster, which took quite awhile.

The Haitian Bleu coffee is very hard to come by right now due to hurricane damage to the very small growing region. Last time I checked, only a few vendors in the US had it, and I think all of them are either sold out or do not know if they can get any of the 2009 crop. I once tried some pre-roasted: it seemed a fairly typical Caribbean coffee, and as such we were not especially fond of it. We tend to like the fuller-bodied coffees.

KT, sounds like you are well on your way to some delicious coffee! Plus, roasting lightly, and drinking the coffee shortly after roasting (couple days) is the best way to maximize the caffeine output of the bean :thumb:

I am curious, though if it matters if the bean is roasted quickly (at a high temp) or not, so long as you harvest it from the roaster at the desired pop. I've only used a pro-grade roaster, which took quite awhile.

Time does matter depending on your tastes. A very fast roast even to first crack can lead to a bright flavor, which some people like. There is also the risk that the outside can be roasted, but the inside is not.

Over the years I have learned that our tastes tend more towards the slower roasted coffees. This means that I use a drum roaster, heatgun/dogbowl or stovetop roasting. I can tell a perceptible taste difference between a fast and slow roast coffee.

Time does matter depending on your tastes. A very fast roast even to first crack can lead to a bright flavor, which some people like. There is also the risk that the outside can be roasted, but the inside is not.

Over the years I have learned that our tastes tend more towards the slower roasted coffees. This means that I use a drum roaster, heatgun/dogbowl or stovetop roasting. I can tell a perceptible taste difference between a fast and slow roast coffee.

My gut feeling when I was roasting that a slow roast would be better. It was my fear that it may not be fully roasted on the inside.

My gut feeling when I was roasting that a slow roast would be better. It was my fear that it may not be fully roasted on the inside.

Crack a few beans in half and eyeball the interior. In my experience, under-roasting most frequently occurs in stovetop pan roasting, when people are mistakenly trying to sear the beans or are not stirring them enough. In this scenario, you can easily end up with a scorched exterior and an almost raw interior. I suspect that your beans have roasted all the way through.

Crack a few beans in half and eyeball the interior. In my experience, under-roasting most frequently occurs in stovetop pan roasting, when people are mistakenly trying to sear the beans or are not stirring them enough. In this scenario, you can easily end up with a scorched exterior and an almost raw interior. I suspect that your beans have roasted all the way through.

That's a good idea. I figured I'd know by the color after I grind them, but cutting one or two through middle would be a much better way to determine.

So I did the taste test today and it was pretty damn good. It definitely had a better 'crema' then usual. There may have been some of that 'bright' flavor, but overall it was very good. I was definitely impressed with the flavor.

OK...here are pics. Let me know what you think of the roast quality MillCreek.

http://img168.imageshack.us/img168/9297/roastedbeans.jpg (http://img168.imageshack.us/my.php?image=roastedbeans.jpg)

Here is one bean cut in half to see the inside (looks roasted through to me).
http://img21.imageshack.us/img21/4839/beancuts.jpg (http://img21.imageshack.us/my.php?image=beancuts.jpg)

That looks pretty darn good. A Full City plus roast, by appearance. There may be some uneveness in the roast or it may just be a function of the lighting. You might want to think about using a long slender tool to stir the beans a bit during the initial stages of roasting if indeed the roast here looks uneven to you. Until the beans start to heat up and expand, the popper fan may not be evenly swirling the beans around.

From the cracked bean, you obviously achieved roasting all the way through. I suspect the flavor will continue to improve over the next couple of days. This looks like an excellent first attempt to me.

I hate you guys, now I want a good cup of coffee to end the evening.....:mad:

Thanks for the compliment. Full City is what I was aiming for. It looks a tad uneven, but not too bad. I did use a chopstick to help stir them in beginning. It seemed obvious as they weren't turning much in the beginning.

As I said, I was quite happy with the taste, so hopefully I'm on the right track. I was just a bit worried about that short roasting time compared to every tutorial I read.

It's nice to have confirmation that it looks good. :) :thumb:


That looks pretty darn good. A Full City plus roast, by appearance. There may be some uneveness in the roast or it may just be a function of the lighting. You might want to think about using a long slender tool to stir the beans a bit during the initial stages of roasting if indeed the roast here looks uneven to you. Until the beans start to heat up and expand, the popper fan may not be evenly swirling the beans around.

From the cracked bean, you obviously achieved roasting all the way through. I suspect the flavor will continue to improve over the next couple of days. This looks like an excellent first attempt to me.

I hate you guys, now I want a good cup of coffee to end the evening.....:mad:

It was so good I made two pots (french press pots = 2 mugs). Hope (wife) had one mug and I had three. :)

It definitely had a better 'crema' then usual. There may have been some of that 'bright' flavor, but overall it was very good.If you used some better interconnects, you'd experience less shimmering and overlapping of tone, and that McIntosh amp would really pop.

I think your next step in your experiment would be to plug the popper into a heavy-gauge 50 or 100 foot extension cord, and see how much that slows down the time to first crack. I would not be surprised if this puts your roast times into the more typical ranges.

A friend of mine had a popper that hit first crack in about 90 seconds. The exterior of the beans were roasted, but the insides were not. A sample cup of that coffee tasted much like drinking raw vegetable matter, and it made a horrible noise going through the grinder.

Seems like a lot of work.

http://www.hillsbros.com/coffee/images/blends/products/med_instantCoffee.png

Seems like a lot of work.Yes, but it saves us from nasty crap like Hills Bros. instant coffee that I wouldn't let past my lips.

Yes, but it saves us from nasty crap like Hills Bros. instant coffee that I wouldn't let past my lips.

You would if you were in prison. :p

I'll admit, I never buy it either, not even for camping. I have a nice lexan French press for that. :thumb:

So, can any of ya'll reccomend me a good coffee roaster for popping my popcorn in?

Hey King, once you get over the joys of hotair popping you can move onto drum roasting! :)

I actually started out just like you many years ago. At that time I found putting a fan (9" metal non-oscillating) under it helped slow down the roast times. But I still couldn't get longer than 5 min roast times. :( I had some Monsoon Malibar gold that was horrid in the air popper.

My tastes grew, so I decided to build a drum roaster. About $15 in parts (perforated steel sheeting, metal chimney caps, pop rivets, etc.) and a $30 rostierie set up and I was in business. Decided to burn through the MM Gold as a test batch. Being able to vary the grill temp, I got a 17 min full city roast (versus 3-4 mins before). Once brewed, that MM Gold was AWESOME!

So long story short, extended roasting times will improve an already good cup of beans. :)

Just beware, now that you've started down the slippery slope there's no telling where you'll stop.

In the ten years I have been roasting my own, I have used a Hearthware Gourmet, a Hearthware Precision, a Whirly-Pop, a Caffe Rosto, an air popper, a stovetop stock pot, heatgun/dogbowl and a Behmor. These days, I use the Behmor 75% of the time, the stovetop stock pot 20% and the heatgun/dogbowl 5% of the time. I use the latter two methods just to keep my hand in, in case something happens to the Behmor. I estimate that I have roasted somewhat over 1000 pounds of coffee and have about 125 pounds of green coffee beans in my garage.

So, can any of ya'll reccomend me a good coffee roaster for popping my popcorn in?

Yes. A Diedrich IR-3, made in lovely Sand Point, Idaho, will keep your entire neighborhood in popcorn:

http://www.diedrichroasters.com/ir3.html

Couldn't you just hook the popcorn popper up to a dimmer switch to slow the roast times down?

I bought one at Walmart for $7 that plugs inline and has a slide switch.

Couldn't you just hook the popcorn popper up to a dimmer switch to slow the roast times down?

I bought one at Walmart for $7 that plugs inline and has a slide switch.

Not sure if the dimmer switch can handle the wattage (or whatever correct electical term) but many people have successfully used a variac to adjust the times.

Using a typical dimmer switch to control a typical air popper is not recommended. It generally cannot handle the wattage. If you are lucky, the breaker trips or fuse blows before the dimmer switch bursts into flames. The coffee roasting forums have some reports in this regard. And variacs are generally more than $ 100.

What some people do, if they are really ambitious, is to get into the popper wiring and install a on-off switch so they can manually cycle the heating element on and off while leaving the fan blowing at all times.

Again, the easy and cheap route is to plug the popper into a long extension cord. The added resistance of the long cord causes enough of a voltage drop to extend the roast times.

You can't give us a story like that and then not show us a picture of your home roasting creation! :thumb:



Hey King, once you get over the joys of hotair popping you can move onto drum roasting! :)

I actually started out just like you many years ago. At that time I found putting a fan (9" metal non-oscillating) under it helped slow down the roast times. But I still couldn't get longer than 5 min roast times. :( I had some Monsoon Malibar gold that was horrid in the air popper.

My tastes grew, so I decided to build a drum roaster. About $15 in parts (perforated steel sheeting, metal chimney caps, pop rivets, etc.) and a $30 rostierie set up and I was in business. Decided to burn through the MM Gold as a test batch. Being able to vary the grill temp, I got a 17 min full city roast (versus 3-4 mins before). Once brewed, that MM Gold was AWESOME!

So long story short, extended roasting times will improve an already good cup of beans. :)

Just beware, now that you've started down the slippery slope there's no telling where you'll stop.

If you ever decide to take the plunge into BBQ drum roasting: http://www.coffeeroastersclub.com/index.php

If I lived in a part of the country where I could roast outside year round, weather permitting, I would very likely have a gas grill/drum roasting setup.

If you ever decide to take the plunge into BBQ drum roasting: http://www.coffeeroastersclub.com/index.php

If I lived in a part of the country where I could roast outside year round, weather permitting, I would very likely have a gas grill/drum roasting setup.
Looks interesting, but how even is the roast? Have you ever tried any roasted that way?

You can't give us a story like that and then not show us a picture of your home roasting creation! :thumb:

I've got pictures buried on the hard drive someplace, but since I'm roasting this afternoon, I'll snap some more. After nearly 5 years she's not pretty, but she's functional. :)

As for the roast results, a lot more even and consistent than with the air popper.

You've never seen such beautiful crema!!! :thumb:

Looks interesting, but how even is the roast? Have you ever tried any roasted that way?

I have tried some roasted that way, and it is as even as the Behmor or any other sort of rotary/drum roaster. These generally give the most even roast of all. I can get pretty even with my stovetop or heatgun/dogbowl with constant whisking, but it is still not as even as my Behmor

A lot of people who live down South in warmer climates, who can roast outdoors (not under cover) all year use this method. It does produce a ton of smoke, however, and it is best if you don't have neighbors within 10 feet of you. I have read about people moving the grill/drum into the garage with the door open when the weather was bad, and they subsequently smoked the entire house out.

I know of a number of people who do 2-5 pound roasts at a time and then sell the coffee at farmers' markets and the like. A potential downside is that your gas grill starts to smell like coffee, so many people pick up a cheap gas grill that they use only for coffee roasting.

Also, if you are just consuming 0.5 pounds of coffee per week, a grill/drum set up would be overkill. I do about four pounds every two weeks, and even that probably is not enough to warrant a grill/drum given the hassle factor with Seattle weather and being able to use it only 6 months out of the year. But if I lived in sunny climes, where all I had to do was go outside and fire it up, I would give it serious thought even at that level of consumption.

You guys are making me feel like I took a step onto a much bigger and more slippery slope than I realized. :p

You guys are making me feel like I took a step onto a much bigger and more slippery slope than I realized. :p

I think I said above that it is hard to go back once you have been sucked in. It helps if you yell "Whee!" periodically as you are sliding.

I think I said above that it is hard to go back once you have been sucked in. It helps if you yell "Whee!" periodically as you are sliding.I think I yelled that quite a few times last Thursday when I roasted. Hope (my wife) kept laughing at the impossible to remove smile on my face the whole time. :thumb:

First attempt at air popper roasting. I was aiming for City+ on both.

Costa Rica "Cafe Sin Limites" roasted this morn. (sorry...a bit blurry)
http://i694.photobucket.com/albums/vv310/skijor/Home%20roasted%20coffee/IMG_1429.jpg

Kenya Nyeri AA Kagumo Coop roasted last Friday.
http://i694.photobucket.com/albums/vv310/skijor/Home%20roasted%20coffee/IMG_1430.jpg

I've graduated to using a whirley popper and my camping stove. Can roast about 1 1/2 cups at a time and have pretty decent control over the temps and the final color.
I blame KT for furthering my addiction though.

Skjor, it looks a little light for City plus. With the amount of chaff still on the Kenya, did it get to first crack?

Skjor, it looks a little light for City plus. With the amount of chaff still on the Kenya, did it get to first crack?

Yup, 1st crack definitely occurred at 4:50. And I ended the roast at 7:00 on the Kenya.

1st crack on the Costa Rica was more like 4:35 and I ended that one at 7:30.

I went mostly by what you and KT discussed in this thread along with the tips for air popping from SM's website. I didn't preheat the popper prior to roasting the Kenya so maybe that's the difference. This was with an old Wearever popcorn pumper that was sitting in the basement. It reachs 415-*425 degrees when I ended these roasts. Glad I didn't throw it out!
Thanks for the input on how done these are. I'll try preheating longer. I have some Sumatran, Ethiopian, and Brazilian beans to try. Been using one of those collapsible steamers and a big metal strainer to cool them and get rid of the chaff.

They sell dimmer switches that go from one light bulb to an entire presentation hall. Just look at the wattage capacity (or just 120V*max amp rating) of your popper, and then go find a dimmer switch rated for that.

Edit: Lutron slide dimmer switches (available at any big hardware store) come in 600 and 1000W ratings. At 1000W you're good to 8.3A. Their rotary dimmer switches can be found rated up to 2000W. If your popcorn popper is drawing more than 16.7 amps then you're either feeding a lot of people, or something is wrong. I'd also be very careful as to what extension cord is used for a 16+amp draw.