DanoM wrote:I'd recommend that you get couple kilos of a low to moderately priced green coffee for starters. Keep lots of notes on what you do for each batch and the taste results of each. Once you start getting that bean to a point where it's palatable and semi-repeatable results you'll have an idea of what you are doing. Of course when you get another bean you'll quickly realize that not all of what you learned can be used the same way on the next bean...

It's the joy of roasting, every bean is a new challenge.

^ +1

I get 6-8 lbs of something from a local roaster I know, work on it for 2 months or so and then on to the next one.

DanoM wrote:I'd recommend that you get couple kilos of a low to moderately priced green coffee for starters. Keep lots of notes on what you do for each batch and the taste results of each. Once you start getting that bean to a point where it's palatable and semi-repeatable results you'll have an idea of what you are doing. Of course when you get another bean you'll quickly realize that not all of what you learned can be used the same way on the next bean...

It's the joy of roasting, every bean is a new challenge.

I was thinking of ordering 5lbs for starters. Good feedback. Perhaps I will bump my order to 8lbs. I have not decided where to buy the beans yet. Sweet Maria's has well respected beans, but there are cheaper options that might be better for this learning experiment. I like the thought of visiting my local roaster. I was planning to do that anyway and chat roasting. He might sell me beans.

Definitely have a notebook (I'm an engineer, more data please!). Maybe take pictures. I think this won't happen for another week or two. It is very cold outside, like 10 degrees F tonight. I've been reading that the drum vessels (this case the dog bowl) shouldn't be sucking heat from the beans during roasting. SO, I may look for a way to insulate the bowl this weekend with something I have in the basement.

Hi Eddy,

Whichever beans you pick should be of enough quality to enjoy the brew. I started out with Sweet Maria's beans 10 years ago and we have enjoyed the results from the beginning using two different roasting machines along the way. Never needed to toss a batch in the trash. Others have varying results.

Have you checked out the cool looking antique coffee bean roasters on eBay? Not suggesting buying one but they are cool looking. If I were to try low-tech, oven roasting would be tried first using the broiler and agitating the beans by shaking the pan with an extended rod.

I still haven't got any green beans. I did visit the local roaster and they said they would sell me beans. But, I had to come back later to chat with Dave the roaster. I'll keep working it. They seemed busy. If I don't get beans next week, I will order some.

Meanwhile, I rigged up my roaster.

This is a 64oz dog bowl, which apparently is capable of roasting 10-13oz of beans. The heat gun is an old Wagner 1400W paint strip gun. I placed the bowl inside a metal pail with fiberglass insulation. All these items I had laying around. However, I added the Taylor grill thermometer which cost me $8.
With no beans, I fired up the heat gun and measured its wattage. 1300W on high, 650W on low. The fan decreased similarly to the heat. So, not a lot of options. To test further, I heated up the bowl and measured temperatures. Unfortunately, the temp gauge has a lot of metal and hence quite a long thermal time constant (take a long time to change temp when heat is applied). Furthermore, the hottest I could get was just over 450F. This was in my warm basement. So, I am a bit concerned my heat gun doesn't have the heat. However, the air temperature measured on my gas grill probe topped 600F, so maybe it will work. I decided to add 10gms of popcorn and see what happen. On high setting, it popped in 2 minutes! So, that is good news. However, the indicated temperature was likely 150 degrees off. After it cooled for an hour, I tried again with low heat setting. This time the temp gauge increased to where I would expect for popping to start. But it was 9 minutes. I may need to get thermocouples. But, I plan to give this setup a try soon.

Today, was my first roast!
Over the past week, I obtained 3lbs of rather nice Ethiopian Harrar natural processed greens from my local roaster. My heatgun/dogbowl setup has been ready for a few weeks now. My local roaster was very kind and gave me lots of advice. Nothing I did not read already, but none the less he is likely willing to sample my coffees and tell me his thoughts.

Well, I got myself a few sheets prepared ahead of time. One with a materials list. Second was a detailed set by step and things to watch as I go through the process. Third was a log.

I logged lots of things. Ambient temperature (45F), 160gms green beans, 7 liguid oz volume, date. I pre-heated the dog bowl to 200F over 5 minutes with the gun on low. Added greens and continued on low. Low is actually half power (unfortunately less airflow too). When my beans lightened slightly after 2-3minutes, I switched to high. At 5 minutes, tanning/grassy smells began and I backed off the heat by pulling the nozzle away by 1.5". First crack started at 9 minutes and ended at 10m 20s. In another minute and a half I think was the beginning of second crack. I dumped (11 min 50 sec) my coffee into some metal screening and put a fan on them. They are dark with a slight sheen, but not oily. Overall, I think the roast went well. My thermometer idea failed. The rare-earth magnet lost its strength with heat and the thermometer got in the way. I had my hands full, so I couldn't log temps anyway.



My setup was in my bulkhead. A little cramped, but a bit warmer than outside freezing temps and no wind.
I would roast here again, I think this spot is ideal for the time being.



My final bean weight is 135.5gms, so they lost 17.6% weight. This sounds a tad bit high, but perhaps being a dark roast, isn't too far off. Taste will tell.

SO, I ground 15gms and pulled a shot with my La Pavoni. Yeah, it tastes a bit burned. But, I can taste a reasonable amount of citrus flavors. The grind was a bit fine as well making a long pull time. Perhaps a few more days and a coarser grind the taste will improve.

Lessons learned. Ditch the thermometer. Perhaps keep the gun on high setting from the start and add less heat by pulling back the nozzle a bit at the beginning. I think the time from 1C to 2C was very quick at roughly 2 minutes. definitely invite my son (age 12) again for helping to log times/comments. I think my agitation could be better next time. My next roast I would want slightly lighter.

Yeah a thermometer setup like that does more harm than good in the sense of chasing your tail to figure things out, same with trying to check temps with an infrared thermometer. Just didn't work effectively for me.

If you continue to use a dog bowl I would suggest using a slow feed type as I switched from an open design to the slow feed and it made a drastic improvement. With the slow feed you can concentrate the heat/nozzle depth much better and agitate with airflow as you circulate around the bowl.

I was quite satisfied with that setup, but decided to build my own heat gun/sifter setup, which can be seen here...

Digital heat gun??? What is wrong with my coffee?

Not long after that pic was taken I incorporated a cordless screwdriver to give precise agitation control and I have put at least 50# (in 200 gram batches) through it and every batch has been spot on. I have tweaked heat settings/agitation speed to obtain more body/depth, but otherwise this thing just works. Best part is I spent maybe $200 total and get superb results from it batch after batch and this is specifically for espresso. I designed it to be modular so any single part of the setup can be replaced cheaply and in a decent time frame. I live in NC so daytime ambient temps can range from 30s to 100 and humidity/wind all over the map. I've successfully roasted as low as 25 degrees with 15-20 mph sustained wind with it.

Regarding yield... I roast all coffees about 20 seconds into 2C and my weight loss is 17-18%. I start with 200 grams and end up with 164-166 and weigh to .1 gram resolution. As long as you're in the 16-20% range I'd say that is acceptable depending on roast level desired.

Thought I would add a bit of my experience with heat guns. I know many have one just laying around or don't want to spend much on one. However, if you plan to do a lot of heat gun roasting and want to do it safely with consistency I can't say enough about the Master Appliance heat guns. I found my VariTemp model on eBay for a great deal. It was used, but well cared for and it just works fantastic roast after roast. Being able to fine tune the heat output from ambient to 1000 degrees and 23 cfm of airflow is awesome for a roaster project. Any single component in it can be replaced if I wear things out.

I did start out with a nice Kobalt brand heat gun from Lowe's that offers adjustable fan speed/temp settings. It worked well for the dog bowl roasting, but can't touch what the Master Appliance models can do.

Thanks Thomas!

Really good job with the HG roaster! Good to hear it produces repeatable, superb results. I may end up doing something like that as time goes on. The slow feed dog bowl looks interesting. However, my heat gun fan doesn't really have the power to push the beans around all that much. Even after 1C. So, if I do get a Master Appliance NG, the bowl upgrade would likely go along with it.

I do feel a bit lost without knowing for sure where the temps were at and how they moved with different nozzle to bean distances and power setting. Sure, the beans lightening, then yellowing, then tan and pops with interesting smells tells me a lot, but I am skeptical if I can repeat very well. I'm going to stick with if for a while and time will tell I guess. I am thinking of getting a dual handheld thermocouple logger. Use it to test my heat gun and other useful things. Perhaps mounting the thermocouple on the end of my paddle will allow bean temps to be logged. If I never use it for all my roasts, I think it still will be a useful tool to have.

Today, I pulled another espresso with the day old roast. This time, with 14gm dose (instead of 15gms) and slightly coarser grind. I also pulled with my group temperature 2 degrees C lower. The burnt flavors were gone! Quite a tasty shot. Dark chocolate and some sweetness with a slight bright ending.

I've decided I have to roast again soon. Unfortunately, that means this weekend. Looking forward to it!

Looks like we have the hook set in this one, we can start reeling him in the boat
Welcome to the slippery slope

Charlene wrote:Hi Eddy,

Whichever beans you pick should be of enough quality to enjoy the brew. I started out with Sweet Maria's beans 10 years ago and we have enjoyed the results from the beginning using two different roasting machines along the way. Never needed to toss a batch in the trash. Others have varying results.

Have you checked out the cool looking antique coffee bean roasters on eBay? Not suggesting buying one but they are cool looking. If I were to try low-tech, oven roasting would be tried first using the broiler and agitating the beans by shaking the pan with an extended rod.

I've found a good source of greens at Green Coffee Buying Club. Been buying from there for over a year and there is always a decent variety at good prices.