Ken
I almost acquired a well used Hottop unit for real cheap to figure out how to do what your asking but was a day late. I can't really afford to buy one just for this purpose. I'm sure it could be done as I now know it can be done with the Behmor. Believe me Ken, the Behmor can be modified and though you would probably prefer your sample roaster as I would my homebuilt hybrid I would bet it could attain your "seal of approval".

farmroast wrote:Ken
I almost acquired a well used Hottop unit for real cheap to figure out how to do what your asking but was a day late. I can't really afford to buy one just for this purpose. I'm sure it could be done as I now know it can be done with the Behmor. Believe me Ken, the Behmor can be modified and though you would probably prefer your sample roaster as I would my homebuilt hybrid I would bet it could attain your "seal of approval".

Ed,

There are a lot of off the shelf roasters out there, however no one seems to want to build a "dream roaster" that could fill the same niche for home roasters, that your cheap E61 box fills for home baristas. Likewise, grinders suitable for home use cover all the bases, and there are many good choices at each level.

Quite a few people in the industry have told me, independently, that they were on the verge of producing a 1lb easily controlled roaster at a reasonable price (say $1000, certainly no more than $1500 US). These conversations have occurred over the last 5 years and have been with at least 3 individuals who either own roaster manufacturers (or are pro roasters themselves), plus one prior participant in this forum who used to have a roasting operation and who was getting ready to start mass producing roasters in the 1lb to 1kg size range. None of these roasters has ever been put on the market. The closest we have to something like this is the Diedrich sample roaster which costs about 6x as much and will never fill this niche.

Becoming a competent home barista is nowhere near as difficult as becoming a competent home roaster. A lot of people roast because they think they will save a lot of money doing it, however this justification for home roasting doesn't really hold up to scrutiny if the individual is seriously interested in quality coffee. There is nothing to stop a serious home barista from negotiating a better price on larger quantities of roasted coffee with a good roaster, then freezing in small batches and using the coffee up over a period of weeks to months. Many people will live within a short distance from a competent professional roaster who may not be quite as good as some of the advertisers on this website, but who nonetheless will get much better results than the home barista would get in his garage, barring some sort of very serious learning curve and effort.

Getting back to hacked home roasters, I am sure that at least some of these roasters can be modified in a way that will enable them to be profiled, at least to some extent. For most of these devices, this is going to work best if the user markedly reduces batch size, which for some will defeat part of the purpose they had in buying the roaster in the first place; the dream of being able to buy a cheap device that will roast a large quantity of coffee in each batch, while still retaining quality. For most people who are not terribly handy, I'd suggest that this "dream" is probably most easily realized with a bbq roaster setup of some sort, rather than trying to get one of these prebuilt home devices to roast a pound (or close to a pound) in each batch. With my current expensive and heavily modified setup, if I include cleanup time and roaster cool down time, I am lucky to have a throughput of 2.25 roasted pounds per hour. This is for a roast session of 6 batches of 1lb of green coffee each batch. The only way I can speed this up while retaining quality, is to roast 10 or more pounds each session, which *maybe* gets my throughput up to 2.5 roasted pounds per hour. And, a 4 hour session in the garage with my sample roaster is a little hard to tolerate, at least for me.

ken

Ken Fox wrote:Back during the zenith of alt.coffee, there were fewer idolized marquee roasters, but at the same time home roasters did not take themselves so seriously. The idea that some guy with a Freshroast would consider himself to be as successful a roaster as some high end professional would have been laughable back then

Actually, the delusions of grandeur among alt.coffee home roasters, including two, one with a Rosto and one with an FR, whose names are too embarrassing to mention, were miles high. It took us years to find out that Ken Davids with popper wasn't the greatest roaster in the universe, that SM Tom wasn't the only person who could cup, that there were places roasting non-oily beans, and that none of us were able to produce a roast lighter than the 2nd crack that didn't smell like someone had dropped a burning mattress into a swimming pool.

Our delusions protecting us while our coffee sucked; but they also stopped us learning how much more we needed to know. Ironically, expertise can do both these things as well.

OK, lets try to get back on track:

Case 1: The coffee everyone raved about, roasted medium as directed, tastes thin and sour. A darker roast of the same coffee also tastes thin, but ashy. You suspect your roaster is not profiling correctly. What would you do? How would you do it?

Case 2 (HB masterclass ): You have an espresso at a cafe, and it's wonderful. You roast and make the same espresso at home, and you can tell it's the same coffee, but it's no longer fabulous. However, you can't quite put your finger on why it's not shining. What's your process for figuring out what went wrong and correcting it?

These are two pretty typical cases of being unhappy with your coffee. Now before proposing courses of action, think about the mix of detective work, equipment upgrades, skill upgrades, and anything else that may be required to correct these. Are we discussing the right problems in this thread?

For case one, i would repeat the two roasts (light and dark) EXACTLY how i did the first time, trying to repeat my first mistake. if my mistake was repeatable then my roaster is at least consistent, and i need to adjust accordingly. for the dark roast, sounds like it might need a faster drying period, to conserve a bit of moisture for the end of the roast, so that sugars are still caramelizing (polymerization) and not just turning into charcoal (breakdown of already formed polymers and the bean itself).

For the lighter roast, is it sour from too short a drying period? Is thinness in a light roast from baking the beans? I don't have enough experience with light roasts to properly diagnose the problem, so i would first read about roasting light and the pitfalls of doing it, figure out if my roaster if up to the task, and start with recommendations from my reading (hint hint )

i'm not enrolled in the HB masterclass, so i won't comment on case two

Ken Fox wrote:<snip>...the dream of being able to buy a cheap device that will roast a large quantity of coffee in each batch, while still retaining quality. For most people who are not terribly handy, I'd suggest that this "dream" is probably most easily realized with a bbq roaster setup of some sort... <snip>

ken

That's a very good point. I've tried a lot of home roasters and they are okay, but it wasn't until I started using the RK Drum a few years ago that I finally felt like I had a good set-up. I'll spare the story and accolades of why I like the bbq drum (from the others I've tried). But Ken is right.

My only challenge is that currently I'm only monitoring the temperature outside of the roasting drum. I have very little indication (other than taste) of what the beans are doing. Sure I could rig something up, but I've been happy (reletively) with the current configuration.

A few points I've learned about my set-up that I don't see others talking about too much (unless I've missed it):

1. Very important to preheat the drum and the grill. Before adding coffee. This seems to work far better (for me) than getting the grill super hot (600F+) and adding a cold drum and beans. With a lower start temp (475F-500F) the beans progress nicely and as long as I do a slight burner adjustment down I can stretch the post FC phase. Main point: don't let anything that is going to contact the coffee get above 500F (again what Ken has already shared).

2. As long as I do #1 I can maintain a grill ambient temp of "475F-ish" and have a nice progression to first crack (about 7-8 minutes) and then lowering the grill ambient temp to "440F-ish" a nice pace until finish. Basically keeping the coffee in a less than 490F environment (again not reading in the drum which I expect is most likely slightly cooler).

In brief summary, get the roaster warmed up (but not extremely hot) and roasting the coffee with as little emphasis on ultra hot burner settings (as if the coffee can only absorb so much heat regardless of how much I try to smoother them in). I'm roasting the same amount of coffee, in the same time frame, with greater control all within a far cooler roast environment. I'm not trying to steer a runaway freight train anymore, rather turning a sedan around an S-curve. I still have a lot to learn, but with very high grill temps my aroma has suffered (non-existent) and my coffee not really been that good (not as good as I want it to be).

Most importantly though: stick to one-pound batches.

JimG wrote:If roaster "A" and roaster "B" can each be configured to drive the bean mass temp (BT) along the same prescribed time/temperature path, to what extent do the beans care, or even know, whether they were roasted in A vs B?

Are they smart enough to know how they were heated?

Or do they only care about the rate at which they changed temperature?

If the variations in air flow and MET from roaster to roaster were relatively less important than BT profile, then a family of device-independent profiles could be developed. Implementing the profiles on a particular roaster then becomes a separate exercise.

Jim

Bean Mass temp alone is not enough to completely characterize the roast. Bean Mass Temp is a 'gross generalization' that does not tell the whole story on how each bean was treated, the MET it was exposed to and the 'micro environment', how it gained (and lost) heat on it's way from green to brown. The reasons are important why MET matters and how it affects the roast, and points to other issues of roaster design and what makes a good roasting device.

You have a simple roaster with temp probes and heater control. What else about the roaster is important to getting high quality results?

Drop your 1 pound charge into the ideal (imaginary) roaster and every single bean in the load is completely immersed in a uniform bath of heat equally on all beans from all directions. The 'profile' guides the bean mass evenly though the roast "temp profile" process. No bean ever looses heat to cooler parts of the vessel(or other beans), heat is conserved in the vessel so that minimum MET is required to get the desired degree of roast. In this case I think your Bean Temp probe would be the ideal representation of how every bean in the batch was roasted.

Take another (extreme) example. An open wire mesh basket over an open propane burner flame. (sound familiar?) Let's say it's winter and 32F out if that helps. Of course we are profile roasting so there is a temp probe in the bean mass and just for fun we burn a MET probe up under the basket, above the flame.....

As the beans (let's say 3/4 lb) roll over in the basket, some pass directly to the flame, taking on considerable heat, then roll on into the cooler bean mass, all the while the 32F ambient air is sucking heat from the beans. The more beans you add to this roaster, the smaller percent of time each bean spends actually being heated. If you looked at the 'real profile' on this poor bean, you would see the surface temps shoot up to scorch and then drop back to much lower temps. (we know enough about roasting that this is very bad for optimum flavor development.)

Those are 2 extremes and every roaster likely falls somewhere between. I don't have enough knowledge on these details to begin to talk about how much heat can be pumped into the beans how unevenly before it really matters (ie: ok if these temp gradients are less than 10F, very bad if they are more than 40, etc) but, the simple tests I have run with the popper indicates these things definitely matter in what you get in the cup. Most of these changes will not show up on the bean temp probe. The most recent test I ran when we had daytime highs in the 90's, 50F dewpoint. All my previous 'MET data' roasts have been around 60F ambient. I was able to run MET about 10F cooler during first crack and achieve a darker roast level with about this same 10F cooler MET because of the higher ambient temps. Same roast level, same Bean Temp, lower MET, different cup. (bonus question: how could I improve the popper design to help mitigate this heat loss problem? how could you improve your roaster to minimise the heat loss from the bean mass, lower MET, and minimise the 'see-saw effect' on temperature pumped into each individual bean?)

Ken Fox wrote: ..............

All I want or need from the Hottop is to control the heat, the fan, and to be able to charge the roaster and dump the beans when I CHOOSE TO DO SO.

ken

Being pragmatic, I would put a variac hardwired to the heater element, another variac hardwired to the fan, and a switch on the drum motor. Add temp probes and a reminder timer and don't leave unattended.

Ken may be right in a world where everybody has the resources (monetary, space, time, etc.) to have exactly the right gear that they need and the time and space to use it in an optimal manner. However, he's dead wrong in the real world where we all have strictures of what we can fit, afford, schedule, etc., and berating folks because what they have the resources to have isn't the optimal setup is both insulting to and needlessly dismissive of those who are working at doing the best that they can with what they've got.

For example, I live in a <1000 sq. ft. apartment with my wife. Outdoor roasting isn't a possibility. Indoor roasting with anything that generates a lot of smoke is out unless I want a visit from the fire department and/or apartment management every time I roast. So my options are reduced by that. I don't have a stock portfolio or investments or a trust fund or a job that pays me six figures. Neither does my wife, so my options are reduced by those factors as well. I don't have a machine shop or access to one, so I'm limited by that. I do, on the other hand, have the space for a Behmor (a definite step up from the Z&D/Nesco I spent the first 5 years of roasting with) and sufficient exhaust capability to deal with the minimal smoke it puts out. I also have a lot of curiosity, read voluminously, and have studied as much as I can of the physics and chemistry of roasting, as well as being a really good amateur cook (and that's not just me saying so, that's feedback from the many friends I have who are restaurant pros), so I've got a pretty good handle on the whole taste thing, to boot. I've spent a lot of time over the last year and a half learning the behavior of the Behmor and how to adjust to its peculiarities and limitations, while applying as much as I can of what I've learned about the roasting process. I buy the best beans I can get my hands on (never anything that's cupped at lower than an 87.5 from multiple sources), and spend several roast cycles with each one, honing in on what's going to give the best results for that particular bean. Since the voltage we get is a little wonky, I added a 18 amp Variac that I picked up for $10 on Ebay to my setup, so that I can come as close to absolute consistency as is possible with what I've got. I don't just push a button and watch things happen. I'm actively involved in riding voltage, adjusting time, and doing what I can to get my roasts where they need to be. I've never burned a roast, or had a lighter roast come out sour and/or grassy since the first few weeks after I first got the Z&D six and a half years ago. I may not have been doing this for 25+ years, but I do know what a good roast (and an excellent one) tastes and smells like, and I manage to hit 'good' consistently and 'excellent' just often enough to keep working on improving my technique so as to get my mean level closer to that point.

So the assumption that those of us with 'push-button' home roasters don't strive for excellence or aren't interested in improving doesn't seem terribly justified to me. I'm freakin' serious about roasting, but have to work within the limitations I've outlined above. If you're lucky enough to not have those limitations, bully for you, but please try and realize that somebody who doesn't have what you consider to be the 'correct' equipment might simply be in a situation where they can't, and yet still be serious about gaining knowledge and moving forward. If you're serious about helping to educate folks who strive to improve, insult, snark, sarcasm, and a dismissive attitude are not exactly the best tools, since they hardly encourage people to listen to anything else one has to say. I actually believe, as apparently Ken does, that blindly following a profile somebody else hands you is not the way to advance your roasting skills, but that an understanding of the process and stages of a roast is the way to go. Because I've been working that end of the skill/knowledge set, my roasts, despite the limitations of what I have to work with, have improved greatly over the past several years.

Think I'm getting more convinced,
there are some profiling generalities, but exact profiles and the best way to achieve them are Roaster,roaster and coffee specific .