Baby roaster and similar - compared to the Gene

[KJM]

Ive used Hazbeans FZRR 700 "Baby" roaster a bit and Ive used a slightly larger but essentially identical roaster (maybe Ill call it the toddler, since it is a bit larger!).

The information on the Baby here on CS says that the roasting process is different from other conventional roasters and this leads to different flavour profiles in the roasted beans; and leads to beans that can be used almost instantly.

Now, I basically agree with those observations, but Ive been wondering why. Having just done 250g of Malawi beans in the "toddler", the thing I noticed as the roast proceeded is that the atmosphere in the roasting chamber is very, very wet. The vent gas from the chamber felt like it was mostly steam. (The "toddler" has a manual crank to turn the drum, and the gas vents through the axle which is a piece of 1/4" pipe - so you get to enjoy the steam every turn > )

Now, if you compare that with the Gene: the Gene has a very high airflow, so the environment within the roasting chamber would be quite dry. And the resulting beans (I would assume) would be much drier too. To a reasonable engineering approximation - the roast time and temperature profile for my Gene roasts and the closed drum roasters would be close to identical. The finished beans are virtually identical in colour too.

Just wondering if anyone else has roasted in a "wet" environment and can comment? Is this the hidden secret to the Baby?

/Kevin

[Dimal]

Re: Baby roaster and similar - compared to the Gene

I havent used anything resembling the Baby or a Toddler : But even so....

In the short time Ive been using the Behmor, Ive noticed a similar thing comparing the end results to that of the Corretto. Batches from the Behmor are definitely ready earlier than those roasted previously with the Corretto and this might be down to a much lower Air-Flow in the Behmor with longer term retention of water within the bean during roasting. Another thing weve noticed with the Behmor too, is that batches (by and large), are quite definitely sweeter in the cup.

Not really sure of the mechanics or science involved, as to why this should be, but perhaps there is something out there that would help to explain what might be going on inside the beans, with these almost polar opposite roasting methods. Would be very interesting to find out Im sure.....

Inquiring (home-roaster) minds would like to know.... 8-) ;D
Mal.

[KJM]

Re: Baby roaster and similar - compared to the Gene

Inquiring (home-roaster) minds would like to know....

Indeed! The thing that bothers me is the standard "drying" time that many commercial roasters employ...

I reckon the roasts are definitely sweeter. I suspect that the issue is caramelisation or something like that, but the chemistry is just way too complex (for me).

The hidden background is that Im working up to build a roaster and am debating the closed "wet" system and the high air-flow fluid bed style. The general net.wisdom seems to be split 50/50 on the issue! Which really doesnt help!!

/Kevin

[Dimal]

Re: Baby roaster and similar - compared to the Gene

I reckon the roasts are definitely sweeter.

Im going to drag out the Corretto in another week or so, for a couple of comparative batches, just to get a more finite handle on the differences with the Behmor (in my case).

I suspect that the issue is caramelisation or something like that, but the chemistry is just way too complex (for me).

Mmmm, could be right Kevin but like you, chemistry has never been a strong suit of mine either. Much better with Physics...

The hidden background is that Im working up to build a roaster  and am debating the closed "wet" system and the high air-flow fluid bed style.  The general net.wisdom seems to be split 50/50 on the issue!  Which really doesnt help!!

I guess it comes down to flavour preferences more than anything. One thing I have noticed with batches from the Behmor (this may not apply to the Baby though), while they seem to be ready for the cup with considerably less rest, the peak flavour and overall freshness doesnt last for as long as those from the Corretto. Probably not a biggie so long as youre able to consume batches in good time....

Definitely warrants some more controlled experimentation though; especially if a decision on roaster design hinges on the outcome. Ive got to say though, as far as quality in the cup goes, I do prefer the sweeter outcomes from the Behmor with no other flavour traits being noticeably depressed or promoted.

Mark from C.R.A. might pick up on this thread and offer some insight....

Mal.

[sidewayss]

Re: Baby roaster and similar - compared to the Gene

I wonder if this analogy might help to understand whats going on.

I did this once before for a Sunday BBQ.
Bunged on a scarlet perch straight on a BBQ with lemon juice and salt, and another one wrapped in foil with same salt, lemon and straight into the oven.

The flavour differences were interesting. While i enjoyed the BBQ fish for its grilled taste, the flavour was not as full as the one foil baked in oven. My friends concurred with me on that one. The opinion was the wrapped fish retained more of its flavour without much of its goodness escaping.

While the Behmor and coretto has hot air surrounding the beans and escaping out, the baby roaster "bathes" the beans with heat retained within inside the semi enclosed environment, with only 3 small holes for heat to escape.

I suspect the "engineer" in you KJM, will test out the two options you mentioned. Create a larger drum style roaster using the principles of the baby roaster with winglets inside and a crank handle attached because it would be damn hard to use the baby style wooden handles for a larger load.

Then create the same, but using similar working model to the Gene for fluid bed roasting and chaff collection. It would have to be innovative enough to be different from the Gene and be affordable.

Gary at G

[KJM]

Re: Baby roaster and similar - compared to the Gene

I suspect the "engineer" in you KJM, will test out the two options you mentioned. Create a larger drum style roaster using the principles of the baby roaster with winglets inside and a crank handle attached because it would be damn hard to use the baby style wooden handles for a larger load.

Then create the same, but using similar working model to the Gene for fluid bed roasting and chaff collection. It would have to be innovative enough to be different from the Gene and be affordable.

Well, yes Of course..

But Id have to finish building the new shed first so I could hide it from Mrs-KJM :

Im also not going to use a crank... Ill use a motor thank you! I find the cranking/turning quite relaxing (apart from the steam issue!) but it keeps me too busy - so I cant switch on the bean cooler and other little things..

I think Im with Mal on the relatively rapid decline in the flavour of roasts done with these style roasters too.

It made me go and try to taste any decline in the Malawi - and I reckon it is there. The beans taste much flatter now; the ones I did in the Gene are significantly nicer right now (and were roasted a few days earlier...). I also think the ones from the Gene are kind-of peaking right now, and the peak flavour is actually better than the peak from the closed roaster.... But I need to do my timing to have both "peaking" simultaneously....

Ill take some pictures of the "toddler" and post them later, since a couple have PMd me about it..

/Kevin

[Dimal]

Re: Baby roaster and similar - compared to the Gene

While the Behmor and coretto has hot air surrounding the beans and escaping out

The Behmor roaster doesnt exhaust a lot of air, although the volume is certainly bigger than the baby of course.

It just goes to show how important it is, to get the air-flow to energy input ratio correct. It has a very marked effect on how the flavours are transferred into the cup. That other corollary oft repeated is also true - One roaster isnt necessarily better than another, just different and it is up to the roast-person to decide how they prefer the result in the cup....

Mal.

[lindsayra]

Re: Baby roaster and similar - compared to the Gene

My speculative tuppence worth:
I would suspect that with high air flow the gaseous roasting environment in a roaster as temperatures exceed 100C would be close to the earths atmospheric composition (78% nitrogen N2 and 21%oxygen O2) while any roaster with restricted air flow would have elevated concentrations of gaseous H2O driven off the beans and products of roasting. For example under some imagined low air flow condition the gaseous roasting environment may have a composition of 39% N2, 10.5% O2 and 50% H2O for example.
I have no idea what effect the elevated H2O would have on the roast result but suggest that the lower N2% would have no marked effect on the chemical reactions during roastings (as N2 is a relatively unreactive gas) while lower O2% (a reactive gas especially at elevated temperatures) would result in less oxidation of coffee bean components, which I speculate would likely be observed as an altered taste profile.
The Baby and Toddler roasters would be regarded as low air flow roasters.
I wonder if any information is available on roasting coffee in an inert atmosphere of nitrogen or other gasses. Would be interesting.
Lindsay
Dont mention Charles et al

[KJM]

Re: Baby roaster and similar - compared to the Gene

Ah yes - I should have thought about the decrease in Oxygen!

I just did a 250g batch this morning (so I have some at a known point to taste over the next week...). The other thing present in the drum, of course, is smoke. Once we hit FC, there is boggins of it. Im sure if I visited the Chemists at work, theyd throw their hands up - way too much going on to tell.

The other significant thing Ive noticed is that the roasted beans are noticeably "softer" after roasting. I take beans into work and put them through a hand grinder. The difference is not at all small - it just jumps out at you. To me, they grind like beans that have been roasted to deadly black death levels do... Curious!

Cheers
/Kevin

[conan.obrien]

Re: Baby roaster and similar - compared to the Gene

I have no idea what effect the elevated H2O would have on the roast result but suggest that the lower N2% would have no marked effect on the chemical reactions during roastings (as N2 is a relatively unreactive gas) while lower O2% (a reactive gas especially at elevated temperatures) would result in less oxidation of coffee bean components, which I speculate would likely be observed as an altered taste profile.
The Baby and Toddler roasters would be regarded as low air flow roasters.

Ive been thinking the same. Also thinking if anybody with a behmoor or KKTO wanted to experiment they could try pumping steam from a boiling kettle into the roast chamber

or throwing 30 ml of almost boiling water into the roast chamber at some point early on in the roast

or dangling a small metal cup full of water from the lid of a kkto

or maybe even dampening the beans just before you start the roast

these things should flush out the air from the roast chamber. Not sure what other effect they would have on your profile. Ive got a popper so I cant do any of this.

Conan

[KJM]

Re: Baby roaster and similar - compared to the Gene

Ive got a popper so I cant do any of this.

True enough. Even if you wet the beans in something like a popper (or even a Gene..) itd dry the beans in a very short time. Venting steam into the roast might not actually reproduce the same conditions though. The wetness from the beans would likely include assorted other goodies that would get vented away in any kind of fluid bed roaster...

Sigh. Too hard for a Sunday evening...

/Kevin

[conan.obrien]

Re: Baby roaster and similar - compared to the Gene

Venting steam into the roast might not actually reproduce the same conditions though. The wetness from the beans would likely include assorted other goodies that would get vented away in any kind of fluid bed roaster...

Hmmm. It depends on what makes the difference. How much is due to the presence of those volatile reaction products, how much is due to the presence of water and how much is due to the absence of o2.

My hunch is that the lack of o2 makes the biggest difference but thats just a guess. Anyone want to rig up a system to inject nitrogen gas into the roast to find out? ;D

Interesting that people have been finding that the beans from closed "wet" roasters are ready sooner but (possibly) decline sooner as well. Maybe they leave compounds in the beans that are super sensitive to o2 and these oxidise quicker? In comparison the roasters with a bit of airflow might oxidise the most fragile compounds during the roast and once they degas they are a bit more resilient. Im just guessing really

Anyone tried putting oxygen absorber sachets in their coffee bags?

[Dimal]

Re: Baby roaster and similar - compared to the Gene

In comparison the roasters with a bit of airflow might oxidise the most fragile compounds during the roast and once they degas they are a bit more resilient. Im just guessing really

Sound like well informed guesses htr 8-)...  Youre not a closet Industrial Chemist by any chance?

Mal.

[conan.obrien]

Re: Baby roaster and similar - compared to the Gene

No, Im a lapsed physicist.

[KJM]

Re: Baby roaster and similar - compared to the Gene

Interesting that people have been finding that the beans from closed "wet" roasters are ready sooner but (possibly) decline sooner as well. Maybe they leave compounds in the beans that are super sensitive to o2 and these oxidise quicker? In comparison the roasters with a bit of airflow might oxidise the most fragile compounds during the roast and once they degas they are a bit more resilient. Im just guessing really

Anyone tried putting oxygen absorber sachets in their coffee bags?

Although I havent tested this myself - beans off-gas and that is supposed to be CO2. The little vent thing on the bags most people use are supposed to let O2 out but not in, so the bags themselves should effectively displace O2..

I havent been able to ascertain any particular differences between the two roasting systems in terms of evolution of C02, but the fresh roasts are much less bubbly...

Too many variables! Get me outa here!

(But Id love to know what is going on!)

/Kevin