You don't get the point of my post. Neither kind of small commercial roaster has any real attraction for the home roaster. Their main cost comes from being built for continuous use. Sample roasters require a lot of skill and continuous attention, cafe roasters are even less profile capable than a Behmor, while the ideal home roaster has the level of automation the owner wants.

{Rant mode on} If you are going to spend 2.5K or or more, right off, on a roaster: 1. Spend about 1.5K and take the roasting and cupping courses at the SCAA, or the new ones licensed by the CQI. Then, based on what you have learned, design your own roaster around any one of the many household appliances or off the shelf roasters that people have used.

I see posts by people who have little or no roasting experience who "want to profile roast." They don't know yet what profile they want, but they are willing to spend all sorts of money to get general purpose profiling ability. I don't know how often to say this: They have it backwards. If you don't know what profile you want and why you want it; why do you want a profile roaster? If you do know, take something that can heat beans, and set it up so it does the profile you want. Then, if you want a new profile, reset it up for that.

Successful home roasters, using whatever they bought, roast and taste enough coffee to know how the roaster needs to be modified. Then the make the modification. Once they go through this cycle enough times, they have come up with a combination of skills and equipment to roast great coffee. Taking classes, like I suggested at the start of the rant, will speed the process up, since you won't be roasting cluelessly to start out, but nothing can replace actually roasting knowledgeably, with some specific piece of equipment, and learning how to use it well. {rant mode off}

In terms of selecting a roaster, here's a simple decision process I would use: Does anyone who's opinion I respect use this roaster successfully? Have I tasted good light roasts from this roaster. Here's my list:

Hottop, yes. P1 and other modded poppers, yes. Heat gun, yes. BBQ roasters, yes. Sample roasters, yes. Z&D, no. Iroast, mostly no (one or two out of a hundred seem to work as intended). Whirlypop, no. Cafe roasters, no. Behmor, don't know, doubt it. SC/TO, don't know, doubt it. Gene, don't know, why is there no buzz at all from it?. YMMV.

another_jim wrote:Cafe roasters like the little Diedriech's, or lots of commercial air roasters, have to reliably roast around 20 pounds per day, look cute, and be workable by the same PBTCs who pull the espressos.

another_jim wrote:In terms of selecting a roaster, here's a simple decision process I would use: Does anyone who's opinion I respect use this roaster successfully? Have I tasted good light roasts from this roaster. Here's my list:

another_jim wrote:Cafe roasters, no.

Hi Jim, maybe I am confusing what you mean by cafe roasters, but are you suggesting you haven't had any good roasts from an Diedrich IR3/7, Probat L5 or the likes? or are you meaning the smaller circa 1kg machines?

Cheers Chris

I mean small 1 to 2 pound counter top roasters. These are mostly air roasters, but there are some small drums too. Some of these may be usable; but as a class they are designed to be "put in this measure of beans, push the button, take the beans out when you hear the beep."

Generally off the shelf home roasters are designed with presets to keep you in the ballpark. Given free control most would not know what to do and the results would be poor. The roaster would then end up in the closet. The other thing is safety. Ron Popeil knew mass market consumers when he coined the phrase "set it and forget it". Forgetting you have beans roasting at upper 400 degrees is not a good thing. Once those d*** cheap thermostats are added it loses it's appeal for me. Beans seem to not like big temp. rollercoasters. There are some experienced homeroasters who say they can get good roasts out of the Behmor but with my tests of it I found shortcomings that I feel need modifications to make me comfortable with it. I added a BT ability, added a faster drum motor and lent it out before I had a chance to add insulation, separate cooling, add MET and bypass the thermostat and presets to run the elements manually with a variac. Or you could PID it but I'm more of a variac kind of a controller. To do a full lb. another element would need to be added. I haven't had a chance to dissect a hottop but would guess it can be modified if desired. The homebuilt IMO is the way to go to get something suited just to your needs. There is nothing out there I'd trade my homebuilt for using except the new one I'm working on. Lots of research is necessary but some good old common sense and yankee ingenuity can get you something useful and for a little more parts money, durable. If small batches are ok the modified popper seems the best route. Or at least could be used to really learn roasting with before deciding on what to go with for larger batches.

another_jim wrote:You don't get the point of my post. Neither kind of small commercial roaster has any real attraction for the home roaster. Their main cost comes from being built for continuous use. Sample roasters require a lot of skill and continuous attention, cafe roasters are even less profile capable than a Behmor, while the ideal home roaster has the level of automation the owner wants.

Yes, actually I got that part. Honestly, I didn't even think about this as I think the "automation" of the Behmor is pretty laughable and does not accomplish the goals one would want with an automated process. Keep in mind I speak as a Behmor user who uses the roaster about 2-3 times a week and I essentially monitor temperature externally and control everything externally to achieve the roast I want.

another_jim wrote:I see posts by people who have little or no roasting experience who "want to profile roast." They don't know yet what profile they want, but they are willing to spend all sorts of money to get general purpose profiling ability. I don't know how often to say this: They have it backwards. If you don't know what profile you want and why you want it; why do you want a profile roaster? If you do know, take something that can heat beans, and set it up so it does the profile you want. Then, if you want a new profile, reset it up for that.

Well, I totally agree with this. Isn't it the way we should approach everything in life? Observe, ask, discover? I personally started roasting on the stovetop, then the air poppers, then got a heat gun. Now I have the Behmor. At each stage, I learned what the major problems and limitations of that method were, which were (combined perhaps with my oafish technique) keeping the roast from being what I wanted it to be.

another_jim wrote:Successful home roasters, using whatever they bought, roast and taste enough coffee to know how the roaster needs to be modified. Then the make the modification.

farmroast wrote:Generally off the shelf home roasters are designed with presets to keep you in the ballpark. The other thing is safety. Ron Popeil knew mass market consumers when he coined the phrase "set it and forget it". Forgetting you have beans roasting at upper 400 degrees is not a good thing. There are some experienced homeroasters who say they can get good roasts out of the Behmor but with my tests of it I found shortcomings that I feel need modifications to make me comfortable with it. I added a BT ability, added a faster drum motor and lent it out before I had a chance to add insulation, separate cooling, add MET and bypass the thermostat and presets to run the elements manually with a variac.

Ugggh.... Why do I have to build everything myself! <violin music here> Ok, I guess it is time to open up the Behmor. Let me at least put the woofer cones back my speakers first though.

drdna wrote:It helps to know what is important in the roast profile. Firstly we are talking about the transfer of heat: how much, how quickly, and how evenly. No question that a larger commercial system will behave differently, but my hunch is that the sample roasters will not be a lot different from the Behmor for small batch sizes.

To put it another way: there is an effect from the batch size of the large commercial roasting machines, but how significant is this? Small home and commercial units have similar "profiling" capability, but can EITHER achieve as good a roast as a Large Commercial drum roaster?

drdna wrote:Ugggh.... Why do I have to build everything myself! <violin music here> Ok, I guess it is time to open up the Behmor. Let me at least put the woofer cones back my speakers first though.

I too have a couple woofers waiting for me to put new surrounds on them.
You don't have to build it yourself but be prepared to spend some bucks as Jim mentioned, the market for what you are looking for is rather small and thus the costs to produce is increased many fold. Even more so for quality components. My drive motor retails in the upper $200 range yet I could have used one for less than $10.

To put it another way: there is an effect from the batch size of the large commercial roasting machines, but how significant is this? Small home and commercial units have similar "profiling" capability, but can EITHER achieve as good a roast as a Large Commercial drum roaster?

When designing my roaster I spent some time looking at heat transfer in a larger drum roaster. I find them to be interesting creatures. The radiant heat from a heavy drum makes a lot of sense. Quite gentle. Just makes it harder to make quicker changes. So air flow is added. It's the conduction that is most interesting to me and IMO what adds the character of a larger drum roaster roast. The beans have rather random momentary contact with the drum wall. Sort of a momentary frying effect. They then transfer their excess surface temp. to other beans they then come in contact with. Not what I would consider Ideal and yet not necessarily a negative in the result to many. A better heavy drum roaster avoids excess tipping as a better fluid bed avoids excess scorching.
The Behmor doesn't have the heavy drum effect. It works with more of a momentary radiant effect similar to the conduction effect of the heavy drum just different.

To continue the thought, Ed...

Talking to a few roaster friends over the last few weeks, we got into a conversation on profiling and how a profile on a smaller roaster would behave on a larger model of the same manufacturer's roaster. At least for one model, the manufacturer recommends adding that profile go up by a certain number number of minutes for each jump in roaster size--2kg, 5kg, 10kg, etc. We continued the thought, and concluded that (absent any specific experiments) the larger bean mass was less available for convective heat transfer--that the mass provides more insulation overall from the heat source. This matches with my memory of convective heat transfer.

This may be true of drums, but not of convection roasters, where the profile is size independent. The larger drums do retard heat transfer, and my guess is that the manufacturers think it's more important to keep the start to finish range of environmental temperatures the same rather than overheating the drum to get the same bean temperature profile.

I agree with them. If I were using a strange roaster for the first time, I'd run it so the environmental temperature ramps from 325 to 475 over about 8 to 10 minutes, and let the profile timing do whatever it wants.

drdna wrote:To put it another way: there is an effect from the batch size of the large commercial roasting machines, but how significant is this? Small home and commercial units have similar "profiling" capability, but can EITHER achieve as good a roast as a Large Commercial drum roaster?

What's the proof that large commercial drum roasters have a better roast product than smaller commercial drums? What is the dividing line between these larger and smaller commercial drum roasters? This quotation makes no sense to me and appears to lack any basis in fact.

I realize that in part you are repeating some things that Jim said earlier in this thread, not all of which I agree with. For example, the 1lb Diedrich roaster is preposterous contraption, but I do think it is capable of very good results. It is overly detailed, as I have said in an earlier thread that made at least one owner of this thing livid. I think I said it reminded me of a Lionel train set. Diedrich appears to have set out to copy all the detailing of their larger roasters and put it into this overly expensive and cute 1lb electric roaster. Nonetheless, I have no reason to believe that this roaster can't have very good results. Aaron Delazzer in Vancouver, working for Ethical Bean roasters in Vancouver, uses one of these as their sample roaster. He told me it does a good job on roasting but a mediocre job on cooling the beans rapidly. And the build quality appears very good. I would expect it to be durable. If home users who buy these things can't get a decent roast product out of them, my suspicion is that this is because they don't know how to roast, not because the roaster is of poor quality.

None of this is to be construed as a recommendation on my part to buy one of these things. I believe the thing is over designed, overbuilt, and fills a niche that does not exist.

If one is willing to spend $6K or so, there are real production 1kg roasters out there and for a couple of thousand more there are many other small commercial drum roasters available for sale from several good roaster manufacturers. That's where I'd spend $6 to $8K if I was looking to spend that much money, long before I'd buy that Diedrich. Nonetheless, I think the Diedrich 1lb roaster can do a good job roasting if you learn how to use it.

ken