Fluid Bed vs Drum Roaster: Exact same results?

[Musicphan]

Mados - is this the same magical machine that doesn't create any acrylamide? If its so great, why the secrecy on who makes the machine?

 

[seeingcoffee]

There is no cupping process on my roaster

Cupping is a way to evaluate coffee. It is not a part of the roasting process.

http://scaa.org/PDF/PR - CUPPING PROTOCOLS V.21NOV2009A.pdf

I don't wont talk about what better Fluid bed or Drum roasters

The thread is titled "Fluid Bed vs Drum Roaster"

But can you make even 5 second video inside drum roaster?

Yes. See the following video:

Daily Coffee News by Roast Magazine ? Must-See Video: GoPro Cameras Inside a Commercial Drum Roaster

 

[peterjschmidt]

Who actually cares about taking pictures inside a coffee roaster? Sounds trivial at best.

For that matter, if you like your fluid air bed roaster, that's great! But to be honest, it sounds like you bought into the marketing hype and now have to defend your purchase with some pretty sketchy claims.

 

[seeingcoffee]

Who actually cares about taking pictures inside a coffee roaster? Sounds trivial at best.

For that matter, if you like your fluid air bed roaster, that's great! But to be honest, it sounds like you bought into the marketing hype and now have to defend your purchase with some pretty sketchy claims.

He has not substantiated any of his claims. He is describing this mysterious roaster that he provides very little information about, yet claims it is superior. The 5 second video he included is elusive at best. In my opinion, he is doing nothing more than seeking an audience.

 

[almico]

The coffee roasted on the fluid bed roaster is constantly punished on cupping tables in body, acidity, and finish. They often have descriptors like baked, flat, and under-developed placed beside them. Roasting these coffees to SCAA standards for cupping, the type of roaster used can easily be responsible for giving a perfectly good coffee weaknesses where they wouldn't otherwise exist.

It is quite possible that results are due to fact that the current rating system's paradigm is based on drum-roasted coffee. When you ask a fluid bed roaster to roast to a drum roaster's standard, then of coarse it would fall short. Try asking a drum roaster to roast to a fluid bed's standard and see how that works out.

If fluid bed technology was superior, reputable manufacturers such as Probat (not Probate), Diedrich, and Giesen would jump on the bandwagon. The reality is they havent. The companies stuck with making fluid bed roasters like Sonofresco, Java Masters, Ashe, and Coffee Crafters are the laughing stock of the industry -- and for a good reason!

So let's be clear, are you saying those manufacturers in particular are the laughing stock of the industry, or the process of fluid bed roasting itself?

 

[Mr.Peaberry]

I'm really sad that this thread so abruptly ended. In my estimation, because coffee is a business first...as proven by Starbucks...the only opinions that really matter, are the opinions of the people who are putting money on the table for the product. In terms of the debate over which coffee is best, a double blind study should be conducted with a random assortment of coffee drinkers and not just elite cuppers who already have ingrained preferreces, that way personal biases of the study participants (cuppers AND those administering the study) do not influence the results. Of course even then, the taste difference can be such that a double blind test will only confirm that a difference exists.

One aspect of the difference between FB & drum roasting that did not come up in this thread is the accumulation of oils and burnt chaff. This is what causes the fire danger in traditional drum roasting, and is almost non existent in fluid bed roasting. One could say FB roasting is a cleaner,truer roast profile, but if the flavor imparted by the "seasoned" drum is part of the lexicon of the coffee elite, and is what is expected to be in the taste profile of quality coffee, then fluid bed roasting will never be able to compete because it does not impart those elements into the bean. There is no reason...in a business sense...to fight gravity, and if a roaster's clientele expects the taste imparted through drum roasting to be in the finished product, then he/she would be a fool to try to retrain their minds...just give 'em what they want if it ain't illegal or immoral...lol! However...if a roaster's clientele is not already biased, there is no reason to believe that fluid bed roasting produces a product that cannot find advocates...as in the case of seeingcoffee who preferred "air roasted" coffee before having an opportunity to work for a company that drum roasted. Most customers will never have the experience that seeingcoffee had, nor the desire to go to such great lengths to distinguish between the two roasting methods.

In my opinion, the ideal situation would be to have the ability to drum roast or air roast according to the customer's preference?? Now there's a novel thought...a customer centric business!!

 

[empeg9000]

In my opinion, the ideal situation would be to have the ability to drum roast or air roast according to the customer's preference?? Now there's a novel thought...a customer centric business!!

Excellent post all around sir!

 

[peterjschmidt]

In terms of the debate over which coffee is best, a double blind study should be conducted with a random assortment of coffee drinkers and not just elite cuppers who already have ingrained preferreces, that way personal biases of the study participants (cuppers AND those administering the study) do not influence the results. Of course even then, the taste difference can be such that a double blind test will only confirm that a difference exists.

If you had too wide of a sample group of coffee drinkers, including Folgers et al on one end and hi-end coffee snobs on the other, the out come would be as you say, it will only confirm that a difference exists.

At the heart is what you allude to in your second paragraph... is a roaster/cafe targeting a certain type/level of coffee fanatic? I'd guess most are. And if they intend to target a customer base who haven't already made up their mind what they want their coffee to taste like, I think they'd have a hard time staying in business. But I would guess that a shop/cafe that had everything else in place - quality staff, pleasant decor, good location - could roast w/ a FAB and get away with it.

 

[Mr.Peaberry]

Excellent post all around sir!

Thanks empeg9000. When I think of the business of coffee, I think of how Starbucks began their worldwide domination of the coffee market under Howard Schultz. The business of coffee is a much different matter than the religion of coffee as evidenced by the vast number of coffee houses that have come and gone during the Starbucks (under HS) era. They have proven that success is possible even when the product does not score well on the cupping table...just sayin'. PJS makes a great point about the ambiance, location and staffing of the coffee house. Just think of any successful restaurant that kicks butt despite a quality challenged menu. No to diverge too much from the discussion of FB (FAB) vs drum roasting. I say...let the customer decide. Carrying a variety of origins, roast profiles, and ultimately even roasting methods, might just be a winning combination.

 

[peterjschmidt]

No to diverge too much from the discussion of FB (FAB) vs drum roasting. I say...let the customer decide. Carrying a variety of origins, roast profiles, and ultimately even roasting methods, might just be a winning combination.

And since most times, the customer's not even aware of what kind of roaster a cafe has, how would they even know?

 

[Mr.Peaberry]

And since most times, the customer's not even aware of what kind of roaster a cafe has, how would they even know?

That's a good point, but I'm suggesting that it would be cool to create a place where ordinary people, who have jobs not related to coffee, who don't have level of passion required to make that journey down the path that folks like seeingcoffee have taken, can experience all of what is being discussed according to their own tastes and interests. To have a menu with options including a dark drum roasted Sumatra pourover or an air roasted Tanzania peaberry from a french press...customers could find a new experience every time they visit. Alas, that could be too overwhelming in the end....

 

[coffeeroastersclub]

Just an observation: Starbucks doesnt sell coffee, they sell ambiance. Personal miff: One of these days the coffee snobs will get that through their heads and stop beating up Starbucks for what they aren't.

Does one want to conquer Starbucks? Do an even better job selling ambiance.

Len

 

[almico]

With the right air temperature control system, will a fluid bed roaster perform the same as a drum roaster like a Probate? If the beans in a fluid bed roaster go through the exact same temperature changes as in a drum roaster, wouldn't the results be exactly the same for both approaches?

I was disappointed this thread stalled too. I was really hoping "seeingcoffee" would make an attempt to substantiate his wildly opinionated claims. Alas, no reply.

To attempt to answer the original post, I think it is easy to ask the question: "If the beans in a fluid bed roaster go through the exact same temperature changes as in a drum roaster", it's a lot harder to duplicate the process in the real world.

Drums and FBs measure bean temp differently so a direct comparison is almost impossible. Even measurements from drum to drum and FB to FB machines differ greatly. It is very difficult to compare roast temperatures unless you are talking about the exact same machines with the probes placed in the exactly same locations. And even then, thermocouples themselves are not that accurate from one to another.

So I believe it's a theoretical exercise at best.

Heat transfer methods are different. Drums are 60% conduction, air roasters 80% convection. It's hard to imagine this does not affect the result at all. It's easy to say "heat is heat", it's harder to prove it. That's like saying an A440 is an A440 because a frequency analyzer says so, but if one note is played on a saxophone and the other a violin, it will sound completely different. Empirical measurements are great for some things; they lack in others.

I can say for sure that coffee beans roasted on a FB machine appear lighter in color on the outside than they do on the inside compared to drum coffee.

Also, in a FB roaster, smoke and chaff are ejected from the roast chamber immediately and do not affect the flavor of the roast. In a drum, some chaff gets ejected with airflow, some is burned up and the subsequent smoke and charr surely affects the result. Some might confuse this smoky charr with "body". I don't. I prefer to sauté my onions with the paper removed.

As a side note: Michael Sivetz raised the issue that this charr could be carcinogenic. As far as I know, it has not been proven with coffee, but has been demonstrated with other "burnt" foods.

So the bottom line is it all comes down to taste. Great coffee can be roasted with either method if the roaster knows what he/she is doing. Starbucks' coffee is drum roasted so take that for what it is worth.

Personally, I prefer brighter, cleaner, drip coffee to "full bodied" espresso drinks, and prefer FB roasted coffee to drum.

 

[boreland]

One aspect of the difference between FB & drum roasting that did not come up in this thread is the accumulation of oils and burnt chaff. This is what causes the fire danger in traditional drum roasting, and is almost non existent in fluid bed roasting. One could say FB roasting is a cleaner,truer roast profile, but if the flavor imparted by the "seasoned" drum is part of the lexicon of the coffee elite, and is what is expected to be in the taste profile of quality coffee, then fluid bed roasting will never be able to compete because it does not impart those elements into the bean.

Perhaps this threat can revived?

So our fluid bed roaster is now fully up and running. It's runs under computer control and any profile can be followed up to about an 8lb batch. It has the capability of being able to do very small batches of 100g. To save energy and to ensure accurate control during the winter months we have the option to recirculate the air. The chaff is removed within the recirculatory system, but smoke I assume does renter the roast chamber, although none appears to escape the system as such so it might be being "burnt" within the heat chamber itself. I'll need to look into this more I guess. So what I'm saying is that perhaps I do duplicate elements of a "seasoned" drum roaster.

I was disappointed that no one wanted to participate in a comparative study. It would take some organizing for sure, and quite a few people would need to be involved. Here are just a few thoughts that come to mind to ensure a fair impartial outcome.

1. I would think two types of roasts would need to be considered. Say a light roasted Kenyan and a medium dark roasted something else.
2. Both parties would have to roast the sample beans on the same day and seal the beans the say way and send to the evaluation team. A trusted agent would have to receive those beans and code them so that the tasting is truly blind.
3. Sample beans would have to be first roasted on the drum roaster and the profile sent to me.
4. I would then roast to the exact same profile an hour or so later.

Drums and FBs measure bean temp differently so a direct comparison is almost impossible. Even measurements from drum to drum and FB to FB machines differ greatly. It is very difficult to compare roast temperatures unless you are talking about the exact same machines with the probes placed in the exactly same locations. And even then, thermocouples themselves are not that accurate from one to another.

So I believe it's a theoretical exercise at best.

Please note that 1st crack should be noted as the temperature profile of the drum roaster will likely be very different from my FB. The important thing is that the beans are roasted along the same curve. If say first crack occurs at 378F on the drum roaster and for me at 388F, I can use spline interpolation to normalize the two systems just to get geeky here. This same issue exists when developing roast profiles on a small sample roaster and then transcribing that profile to a large commercial machine.

5. Both sets of beans would be sent to a trusted agent who would code them and an small group of tasters would do the cupping. The trusted agent would present the results.

 

[Razzo]

The problem with a study that was suggested is that you could never get unbiased results, only good opinions. I work in the medical device industry which is highly regulated. One of the first requirements for assessing process capability/product quality is a requirement for a qualified measurement system. The tool for qualifying your measurement system is called a Gage Repeatability and Reproducibility study (GR&R). This requires 5-10 samples of the product to be measured by 2-3 operators, 2-3 trials and the results statistically compared. The typical study consists of 3 testers, 10 samples, run 3 different times. The results are then run through a formula where the end result is expressed % study variation. A very good study will be 10% or less, an acceptable study will be between 10%-20%, a marginal study will be between 20%-30% and anything over 30% is back to the drawing board. I can’t imagine where 3 cuppers would get the precision needed to have an acceptable % study variation.
On a side note, has anyone compared the fuel usage between a FB and drum roaster? This would be a worthwhile comparison as it would affect the final product cost to your customers.