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JackH
12/14/2019 4:07 AM
I read somewhere that higher elevations have faster roast time and require somewhat lower temperatures. air is thin and has less Oxygen

allenb
12/14/2019 12:44 AM
Yes, 1st off, you must use only Panama Esmeralda Geisha beans and be sure to only roast on Saturdays. Actually, this isn't completely true. Please post in all about roasters forum. Thx!

wjohndon4566
12/13/2019 10:36 AM
I’m at 9,000 feet elevation, is there any special adjustments that need to be made to roast using an SR 540 at this elevation?

snwcmpr
12/07/2019 9:29 AM
roar

snwcmpr
11/27/2019 11:44 AM
greenman

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time to c1
mtntrail
I put together a kit from RK Drums and have been roasting with pretty good results for a couple of months. Shane at RK recommends hitting c1 at 6 min. for a 1/2 pound charge. I am wondering what others with this set up target for c1 with the same weight of beans. I have been following Rao's 80% suggestion for hitting end of roast, so going to about 7 1/2 to 8 min total roast time. This takes the beans right towards the end of c1 and I am getting decent coffee. In reading many of the posts, it seems like people go longer times in general using other kinds of drum roasters. So just looking for some feedback. Thanks.
 
David
Welcome to the Co-op. mtntrail. Nice first post.
Without quibbling about the 80% idea, I'd say keep the same timing to first crack, but then stretch out the time afterward so it comes closer to second crack. There is a lot of mellowing going on during that time frame that percentage solutions don't take into account. There are chemical changes going on that are independent of how many other beans are doing the same thing at the same time.
On my RK, I cut the heat way back in the middle of first crack (or turn it off completely) and let it coast toward second crack. Sometimes it reaches second and sometimes it doesn't, but I think the coffee has a deeper, richer, less acidic flavor. YMMV.
 
mtntrail
Thanks David that is exactly the info I am looking for. I have been cutting the heat once c1 is rolling about 20 to 30 degrees f. So it sounds like I might want to let things go a bit longer. I do prefer about a city roast level and have had a few just go crashing into c2 so have been a little paranoid about letting it go too far. Is there any danger of "stalling" that I hear so much about while stretching out the roast?
 
HoldTheOnions
I have a fluid bed roaster and haven't been doing this for very long; but the way I look at it is there are things that will kill your roast and give bland, muted, or wrong flavors, and other things that will simply change the character of your roast, but not destroy the flavor, i.e. I still like it. The key is to figure out what does which for you. For example, I like variety in my roast levels, so if my roast level ends up different than what I planned for, but it still has full flavor, then I'm good. For someone else, missing the roast level could be a disaster.

The two deal breakers I've figured so far for me to get full flavor are reaching 1c in the 8-10 minute range and, most recently, also keeping the bean temp from stalling out. The further off I am from these, the more likely I am to get bland, muted flavors. For me, 6 minutes seems to be on the short end of getting a good roast and 12 minutes on the long end. Keeping the bean temps increasing smoothly has taken a little practice, but I am definitely seeing the benefit of a nice RoR curve.

Everything else, I can taste the differences they make in the roasts but they aren't deal breakers for me. For example, I can clearly taste the difference between hitting 300f in 3 minutes or hitting it in 6 minutes, but if my RoR and 1c times are good, then either way still tastes good to me, just different.

Same goes for the 75-80 rule, I am just not finding it to be critical to my enjoyment of the roast, in fact I am actually find it better to ignore the rule when trying to achieve darker roasts.

That's all I got. :-)
 
Mad Mac
I pretty much do what David does on my heat gun bread maker. I roast 100g until chamber temp reaches 215C. 1C begins. Then cut the heat. When it drops to 200C I turn on the heat and the cycle continues until end of 1C. This is when late beans catch up while the leading beans don't burn. My total roast time is 11min.

Done this way I get a deeper developed roast flavor and still get the acidity I like from City roast. Varietal differences are preserved.

However, unlike my old method of roasting until 229C, knowing when to stop is back to being an art. Color and end of first cracks.
Edited by Mad Mac on 12/01/2014 5:16 PM
 
David
mtntrail wrote: do prefer about a city roast level and have had a few just go crashing into c2 so have been a little paranoid about letting it go too far. Is there any danger of "stalling" that I hear so much about while stretching out the roast?
Yep, stalling definitely is a risk.

This gets a bit more complex rather quickly. Please bear with me for a couple of sentences of techie talk and a car analogy. Think of the mass of beans as having a certain "momentum." which increases as the temperature rises. So, the rate of rise would be the measure of acceleration. In practical terms, working with larger batches many roasters cut back on the heat (thermic force) a minute or two before first crack, just as you might back off on the gas pedal just before your car reaches the very top of the hill (maybe to avoid the speed trap on the other side!). Then the rate of rise has already settled down and there is less slamming on the brakes to avoid "crashing into c2" or stalling out (flat or falling temperature) due to cutting back too much, too quickly.

We are discussing the externals now, but the real action is down where chemical changes are going on inside the bean. Roasting is cooking, and cooking is chemistry. Everything relates to what chemical reactions we are facilitating (or not) by our roast "profile." So, the conventional wisdom is to keep the temperatures rising enough that you would definitely reach second crack. That avoids the stall. OTOH, you need to do this slowly enough that there isn't such a build-up of momentum that it will go crashing through second crack, and maybe even on to the dreaded Third Crack. ShockShockShock

Another complication that you will hear about is that the beans will go from endothermic (taking in heat) to exothermic (giving off heat). It's not exactly that they "catch on fire" (that's third crack), but you can think of it that way because the cellulose in the cell walls is breaking down due to the heat. When heat given off by the beans gets added to the heat from the roaster... well, that's where a lot of roasts go out of control. Perhaps you already know this.smoking

One more thing, it's important to know that second crack can be smelled and seen before it can be heard. That nice campfire aroma starts to get acrid and nasty - like burning paper - and the smoke starts to get thick and bluish. That happens about a minute or so before you can hear the Rice Crispies. It's a good marker for End of Roast, if you are trying to stop short of second crack.

A good calibration experiment is to "burn a batch" of cheap beans.
You will be playing Boy/Girl Scientist here for a while. For starters, jot down the weight and kind of beans you are using and the ambient temperature. Then, set the heat as you might ordinarily do for a roast. Jot down the pre-heat temperature you are using. Put in the beans and start your timer as you usually do. Jot down the lowest temperature the roaster drops to when the cold beans go in. Mark the time to the first outliers before first crack, mark rolling first crack (one pop per second), mark the end of first crack (less than one pop per second), mark the time of the smoke and smell change, mark the outliers of second crack, mark the beginning of second crack and mark the end of second crack. It's optional after that whether you want to go to ignition. Watch for any temperature stalls along the way. If it stalls before second crack, that's a problem. If it stalls after that, no problem unless you are going for a CharBucks flavor. Throw those beans away and write off the cost.

Do this just once and you will have a lot of useful knowledge about your particular roaster, whatever kind it may be. You can tweak it from there to get the roast profile you are looking for. You will also have most of the information you will need to converse with even the geekiest of roasters. ThumbsUp

There are good articles on this here at homeroasters.org; for example, http://forum.home...ad_id=3104
It's a great topic and threads on "stalling" can be found at CoffeeGeek.com, home-barista.org, roastersguild.com and good ol' sweetmarias.com.
Having said that, please try our local posts first.

Enjoy your adventure into coffee roasting. It's seriously good fun.
 
mtntrail
David again thanks for such a detailed response. I know there is a lot of redundancy in these basic questions. I have read so much online but I think the real learning comes from doing, which in turn, generates these specific repeated questions. So thanks for this plan of attack.
I have done the zero to carbon sequence on my air popper but not with the drum. I have been simply following Shane's advice from RK. I then picked up Rao's "Roasters Companion" and noticed his three guides of starting hot, decreasing ror, and 75 to 80 percent to c1 are consistent with Shane's technique. He admittedly does not fine tune much but recommended further experimentation like dropping e temps a bit in c1.
I will run the sample batch and log temps etc for a baseline. My remaining question regarding stretching out the roast and avoiding stalling is this. I do not have a themocouple in the bean mass and am monitoring relative heat at the top of the BBQ with a quality thermometer purchased with the kit. So roasting by time and relative heat as per Shane.
My displayed temp is 600f which takes me to c1 In 6 min. with a 1/2 lb load. At c1 I turn down the heat about 30 degrees and maintain that until end of roast. So without a bean temp readout is it even possible to know if a stall is ocurring? I guess that is what puzzles me . Is that a shortcoming of the BBQ roaster or is the relative temp monitoring sufficient once you "know" the roaster?
 
Mad Mac
I roast small batches and only use pot temp and not bean mass temp. I use a cheap thermocouple bought off ebay. I find the pot temp to be very reliable basis for my roasts. I note the temp at which my first cracks appear and keep the temp around that range towards the end of the roast. As long as I hear some cracks I know I am not stalling the beans.
 
David
Mad Mac wrote:As long as I hear some cracks I know I am not stalling the beans.
Understood. Your method sounds good. However, what we are talking about here is the time period between the end of 1C and the beginning of 2C when there aren't any bean noises.
mtntrail wrote: So without a bean temp readout is it even possible to know if a stall is ocurring? I guess that is what puzzles me . Is that a shortcoming of the BBQ roaster or is the relative temp monitoring sufficient once you "know" the roaster?
To test whether it is stalling, simply let it continue to roast and see if and when 2C comes. If it never comes or if it takes more than four or five minutes max, then consider it stalled. Whether technically it is "stalled" or not, the answer if the same -- it needs more heat.

Do this a few times at different temperatures and you'll be another step closer to knowing your roaster. You’ll probably be roasting to a darker level than would be your preference to get the data you need.

Relative temperature - An ideal measure will be both valid and reliable. If your measure of the temperature inside your roaster is reliable, then it doesn’t have to be valid. For example, my bathroom scales may or may not be totally accurate, but I can tell if my weight has gone up or down. Since you are looking at changes in temperature over time AND noting when 1C occurs on your thermometer on your roaster, you’ll be fine with the relative measure. As you know, where you place the thermometer affects the temperature readout.

Bean temperature – It’s not really measurable in our world. The best we can do is to get a probe into the bean mass and go from there. Besides, the temperature will vary within the bean itself, hotter on the outside and cooler on the inside, at least until the heat fully penetrates it.

Side note on temperatures – Back in the day when the Atlanta HUGs group was meeting on a regular basis, Bob, our host, often mentioned wanting to buy an RK drum. Since Ron Kyle lived just over the state line in SC, Bob invited him to come give a live demonstration of his drum so that Bob could decide whether to purchase one. Ron came over and showed us the roasting process he had developed around his four-pound drum. He fielded a lot of questions as the roasting process. One of them had to do with thermometers. He said that at first he had placed several types of thermometers at various locations on the roaster’s lid, etc. Long story short, he found the fancy ones to be too sensitive to minor fluctuations and pushed him to make too many adjustments to the heat. He concluded that for his purposes the simple oven thermometer was good enough, and actually better, for the RK Drum. It was “set it and forget it” – kinda, sorta. He did make a few strategic adjustments based on where the beans were in the roasting process.
 
mtntrail
OK so as long as c1 is happening I can assume that it is not stalling, but if it doesn't go into c2 without additional heat, then stalling is likely? Your take on relative heat and pegging it to the temp at c1 is the conclusion I sort of logically came to prior to deciding to build the bbq roaster. It seemed to me that even with a temp probe in my poppery beans that I was probably getting a mixture of ET, BT, and convection/radiant heat from the elements. So trying to tease out exactly what is happening in the bean was pretty much futile as any measurement technique is going to be a relative one, albeit less of an extrapolation for a probe completely covered with beans.
Eventhough I thought the relative temps would be adequate for roasting, so much is said regarding computerized readouts, precision readings from multiple probes etc. that I began to think that I should have gone for something with better heat monitoring ability. That being said I am sure that a setup that allows more accurate estimates of bean temp can result in a far better roast than the bbq roaster. I just want to be able to get some decent coffee where I can taste some of the origin flavors, but have no illusions of getting the perfect cup!
So the other side of this ever expanding coin, is understanding the flaws in the brewed coffee and how those relate to the roasting process assuming I have my brewing dialed in. Coincidentally with that then is understanding what to modify in the roast profile to enhance or counteract the qualities in the cup. I am picking up bits and pieces of this information in my reading of various threads. I am wondering if there is a distillation somewhere that describes flaws, their causes and suggested solutions during the roast, or is locating the info part of the fun? ;)
 
David
mtntrail wrote:OK so as long as c1 is happening I can assume that it is not stalling, but if it doesn't go into c2 without additional heat, then stalling is likely?
Yes. Egg-zackly.

I think the two main upsides of the BBQ Roaster are that you can roast larger batches and you can achieve some of the deep, mellow flavors that are so hard to get with a fluid bed roaster. Three downsides that come to mind are: you can't see the color of the roast as it develops (I miss that); you can't get a bean probe into the tumbling bean mass without some very fancy electrical connections to pass a signal through the axle of the rotating drum; and there is a smokey flavor that gets added due to the trapped smoke under the the hood from a point about a minture before 1C and onward.
The big boy's roasters have the furnace chamber separated from the roasting chamber. The heated air is blown through the roasting chamber at whatever temperature and rate the roastmaster desires and the smoke gets exhausted out the other end. With the BBQ drum it hard to get rid of the smoke except by lifting the lid repeatedly.
Even with all that, I still love my BBQ grill and RK Drum set-up.
 
Mad Mac
Whatever method you use, it will help to put a temp logger. It's the easiest way to replicate a roast profile.
 
mtntrail
I am the temp logger, pencil and paper, ha!
David what about a fan mounted underneath the bbq to help clear out the smoke?
 
David
mtntrail wrote:I am the temp logger, pencil and paper, ha! David what about a fan mounted underneath the bbq to help clear out the smoke?
I'm sure that would clear it out, but it might cause too much heat to escape as well. You could always try and see.
Since you don't roast all the way up to 2C, it may be a non-issue. The smoke that I am talking about comes just before 2C.
 
mtntrail
Yes I have never had smoke that I could see with the exception of the roast or two where I inadvertently went into c2. There is quite a bit of burned chaff on the grill plates when I am done, but I can't say that I have tasted anything like a smokey quality to the coffee. I have 4 burners and have no problem getting hot enough, but if increasing airflow would not really be of benefit it is one less thing to deal with. My takeaway is that bbq roasters dont typically use fans.
I printed out your previous posts on finetuning my roasting and plan on running some roasts this weekend to get things dialed in better. Weather is a little iffy, finally getting rain in northern California so cant complain too much!
Don
 
allenb
mtntrail wrote:

Even though I thought the relative temps would be adequate for roasting, so much is said regarding computerized readouts, precision readings from multiple probes etc. that I began to think that I should have gone for something with better heat monitoring ability. That being said I am sure that a setup that allows more accurate estimates of bean temp can result in a far better roast than the bbq roaster.


This is a very interesting discussion. I often wondered how folks were getting repeatable results with so little feedack from a BBQ grill roaster.

One thing that has become obvious to me is besides not knowing bean temperature we also don't have a way to see how much energy our burner is putting out other than a rough idea of burner valve position and temperature at the top of the grill lid. Being able to accurately adjust burner BTU output would be a huge benefit in a couple of ways. 1. Be able to accurately change burner output at key stages of the roast, 2. Be able to repeat it from roast to roast.

A way to accomplish this is to add a good needle valve and pressure gauge between the regulator and valve manifold. Install the valve and gauge in a location allowing easy access and convenient viewing of the pressure gauge.

One possible snag will be finding a gauge capable of reading in inches of water column since a stock BBQ grill uses a low pressure reg outputting 10.5" water column. I'm not sure if a gauge that measures this low in pressure is going to be affordable. Maybe something to look into.

Allen
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
 
allenb
allenb wrote:

One possible snag will be finding a gauge capable of reading in inches of water column since a stock BBQ grill uses a low pressure reg outputting 10.5" water column. I'm not sure if a gauge that measures this low in pressure is going to be affordable. Maybe something to look into.



Looks like a gauge that reads inches of water column for a grill is not any more expensive than for high pressure.

One example:

http://www.amazon...B00H9ZWHV4

To use a needle valve with a grill, crank the needle valve full open, light the burners, turn the burner valves full open, adjust needle valve to control heat output as needed. If we keep all of the grill burner valves full open then we'll be able to have repeatable results when making adjustments to the needle valve.

Allen
Edited by allenb on 12/07/2014 4:45 AM
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
 
scarter11
I upgraded the regulator on my 4 burner grill to a 1-10psi high pressure model from Academy Sports, and I get a much better blue flame. However, I would like to add a gauge so that I can make controlled adjustments from the regulator. Would this 0-15PSI guage do the trick? Would 50% head room be enough?

https://www.grain...lso_Viewed

Thanks!

Scott
 
www.trefratellicoffee.com
allenb
One thing to determine prior to deciding on the gauge's pressure range. Do you see the flame operating in a useful fashion (stable flame without lifting off of the burner) throughout the adjustment range of the regulator? If you're only able to adjust 1/4 to 1/2 of the range of the regulator before the flame gets weird then you will most likely want closer to a 0 to 5 psi gauge but that is going to be a guess. Does the flame stay in good shape all the way to maximum output of the regulator?

The most useful pressure gauge is one where the needle travels at least 3/4 of full scale when adjusting the burner from low to highest normally encountered pressure. This allows one to see good resolution when making changes.

Allen
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
 
scarter11
That makes sense. The few things I read recommended as much as double the expected capacity to protect from over pressure situations. But you are right, if I open the valve too much, the flame struggles. I marked the best max power setting on the dial. 3/4 of a turn from fully closed is likely where I would run it for full power, where fully open is 3 full turns. Let me search for a lower psi range.
 
www.trefratellicoffee.com
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