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Post by timwilde on Apr 13, 2014 16:11:39 GMT -5
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Post by lyndon on Apr 16, 2014 16:36:48 GMT -5
Thanks, those photos are great. I'm going to order the parts I need for my own next month,although I am sure mine won't look quite so good.
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Post by lilypa on Jul 14, 2014 14:12:15 GMT -5
Hey Tim,
How has your DIY roasting been going now? What drum size are you using now? What's the maximum weight of cocoa beans you've roasted now? I'm contemplating doing this as well to a) give myself some temp and more time control over my Behmor 1600 and b) to possibly increase my roasting capacity. I think I measured the Behmor drum at 10" long by 4-5/8" in diameter. Alchemist John says you can get between 2.5 - 3 lb roasts out of it. I've mostly stuck to <=2.5 lb roasts. But, I was thinking on a volumetric basic that if I could fabricate a larger drum than the Behmor's for a DIY rotisserie/convection roaster that I could increase my roast capacity in a proportional way. For instance, the Behmor's drum volume is about 168 cu. inches. If I could make a drum that was say 11" in length by 6" in diameter I would have a volume of 311 cu. inches. Using the volumetric ratio of 311/168, seems like I could increase my roast capacity by 1.85 times (potentially 4.6 - 5.5 lbs of cocoa beans) compared to the Behmor. Does this seem like a reasonable assumption?
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Post by timwilde on Jul 22, 2014 3:09:50 GMT -5
still using the same drum. It's running at about 10"x6" cylinder. The most i've attempted roasting is 3.5lbs and it did so like a champ. Using the coffee roasting capacity formula, it should be good for up to 4.1lbs of cocoa (approximately 1.75-2lbs coffee) The 3.5lb roast came out beautiful, even roast across all the beans. Using the DIY setup, I've tested 2 2lb roasts, one using the upper heating elements and one using the lower elements - i personally couldnt tell a difference in the roasting. Bean temps came out the same and otherwise the roasting profile was identical for testing purposes.
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Post by lilypa on Jul 23, 2014 17:15:21 GMT -5
Thanks Tim! That's really encouraging. I've been looking around at different convection ovens and I'm thinking of getting the Black & Decker CTO7100b. Seems like it has a decent interior dimensions (larger than the Behmor.) Note the Behmor's peak wattage is 1630W, while the B&D's is 1500W. Of course, since I'll be roasting at lower temps it probably won't matter much. Also, good to know that you didn't notice any difference between the upper and lower heating elements. BTW, what is the coffee roasting capacity formula that you used?
By comparing volumes between your drum (283 cu. in) and the Behmor's drum (168 cu. in) and what Alchemist John mentioned you could scale the Behmor to cocoa beans instead of coffee beans, seems like you could possibly roast between 4.2 - 5.0 lbs of cocoa beans in your DIY drum roaster. John mentions that the Behmor can roast between 2.5 - 3 lbs of cocoa beans. I multiplied that weight range by 1.683 (your DIY drum volume/Behmor drum volume). So, that bottom end (4.2 lbs) is right on target with your 4.1 lb estimate based on your coffee roasting capacity formula.
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Post by Alchemist on Jul 25, 2014 8:05:25 GMT -5
timwilde, Rather nice work. As I was reading the post, you echoed and did nearly everything I did with a rotisserie about 7 years, re-wiring and all. I ended up giving up on the project because I could not see most people doing what is required to make it half way workable. But yeah, isn't is so much nicer than the over?  I have to say, I never liked the 1 hour roast times though. An hour was just too limited in control for my taste. I'm thrilled that it is working for you though1!
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Post by Ben on Jul 25, 2014 9:41:34 GMT -5
Why do the roasts take so long? The oven is roughly comparable in power to the Behmor, right? Shouldn't it be able to do quicker roasts? Tim mentioned putting the beans in a cold oven. Does it just need to be preheated first?
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Post by Alchemist on Jul 25, 2014 10:57:15 GMT -5
What I found is that you can have either of the two elements on. In my case, it was rated 1500 watts, but that was the combination of both elements that never turned on at the same time. Either Bake for the lower or Broil for the upper. And each was about 750 watts. I don't of course know what Tim did, but he didn't specifically mention enabling both elements. Temperature limit and power input are two different animals.
Also, if he set it for 350 F (for instance, noting his 'cooler roasting temp' then it was cycling off too early IMO. When I roast in my roaster of 20 amps, it is on FULL BLAST for the first half of the roast, ambient temperature be damned. If I kept it partial power and a lower temperature I would have an extended roast to.
Care to chime in with details Tim?
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Post by lilypa on Jul 31, 2014 17:50:37 GMT -5
Hey Tim,
Just trying to get your attention. See posts above from Alchemist John and Ben? I'd like to know too.
Cheers,
Dave
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Post by timwilde on Aug 6, 2014 17:57:02 GMT -5
Hi guys! Good to see the interest. This was kind of the first attempt at all beyond using just the oven and a stoneware bowl, so I didnt have any idea of what to look for or anything. Everything in the roaster was 100% stock, with the exception of adding the switches for the convection and rotisserie functions. So the heating elements are whatever the Faberware specs are for that model. For roasting profiles I've just been manually controlling the temperature setting knob and using the timer countdown function that actually turns the power on. I sit nearby so as I either smell changes or hear the "ding" I go over and change the temps accordingly. I think my oven only goes to 450, so when I set to 450, that would be the proverbial "full power". Something else to note, the only beans I've had on hand have been the Mantuano. The profile I've mentioned seems to do these beans quite a bit of justice. At first I thought I was going overboard by letting the profile extend upwards of an hour during the experimenting, but it seems that it pays to just follow the beans. I like the gradual heatup and hold from a cold roaster to the hottest temp then a gradual cool-down to the roasting temps where I hold at 200 or less for the vast majority of time. YMMV though  BTW: the formula I used was found on a coffee roaster site, but for the life of me I cant find that page again. I used John's rule of thumb with the behmor, essentially just double the coffee volume and you've got your cocoa volume. So, I would assume that as long as I was willing to sacrifice the roast, It would be trial and error to find out exactly where the sweet spot is. 4.1lbs was the figure that came out from using the coffee roaster formula, doubled for cocoa (so 2.05lbs for coffee). However, 3.5lbs only fills about 1/3 of the drum, so I'm not sure exactly what that ratio needs to be, or what the starting point for theoretical max limit would be. |
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Post by timwilde on Aug 6, 2014 19:10:01 GMT -5
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Post by lyndon on Aug 7, 2014 4:07:14 GMT -5
Do you have to put the beans into a cold oven or is it easy enough to preheat and then insert the cage? I'm stuck between doing things the way Ben has, with a large oven and a power drill to rotate a drum, or this. Having to rewire heating elements and fans etc seems complicated |
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Post by timwilde on Aug 7, 2014 7:55:03 GMT -5
Well, the benefits of Bens oven is that you can obviously use a much much larger drum and do things in a much much larger volume. Awesome if you have to work at volume. The rotissery/toaster oven is great if you're just starting out and dont have to roast large volumes of beans. I never rewired heating elements. The re-wiring was super simple and I think would be just about as complex as configuring things up to use a drill to turn a drum at the right speed. Making isnt for everyone, but the equipment needed for chocolate does seem to lend itself to making |
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Post by lyndon on Aug 7, 2014 9:03:39 GMT -5
And you ended up using the 560 Cubic Inches model? I've been looking at a 40 litre capacity one (2500 cu in) at 2000W, which I presume I can fit a larger drum in, hopefully upwards of 2kg beans. Being able to preheat it and safely insert the drum without burning myself would be a good trick though |
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Post by Ben on Aug 7, 2014 12:25:07 GMT -5
I use these gloves for loading and unloading the drum. www.webstaurantstore.com/san-jamar-ml5000-hot-mill-knit-gloves/167ML5000.htmlWhen I make one of these small roasters will be for test batches of a couple pounds or so. I'd want to make sure it could reasonably replicate the roasting curve of my larger roaster. Side note: my oven roaster is not long for this world. I'm going to be upgrading to a larger, gas roaster soon. |
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