minus1psi wrote:Here are a couple of recent recent roasts with the Popcorn Pumper and IR sensor.

Thanks for summarizing the Hoos interview. And thanks to both of you posting up your curves.

Without paying much attention to this previously as a target metric, my favorite roasts have been in the 14% weight loss range. Medium light has been my pronoun of choice for them (ha!).

Did either of you notice any difference between the two (low vs higher charge temp) on the cupping table?

pcofftenyo wrote: Did either of you notice any difference between the two (low vs higher charge temp) on the cupping table?

Reply moved to a new thread.

Short version of that post: you have given me a New Year's resolution to add to the list!

minus1psi wrote: Today's two roasts both dropped at approx. 377°F on my roaster. Given the IR sensor that is being used outside of its design parameters I do not know what the actual temperature was. As long as the sensor is consistent, it is workable.

The roasts today differed in the way heat was applied. Both were given an initial blast of power to get the beans moving, then the voltage was quickly reduced. There were two things that were similar about the roasts, the drop temperature and the weight loss. Otherwise they were quite different.

The first roast (#125) ran at 110v almost the entire time; the charge temperature was about 65°F lower than the charge temperature for the second roast. Right about the time I called 1C I also gave the roast a few seconds at 120v hoping to blow off chaff and to increase the volume of the cracking sound (1C cracks remained barely audible). Other than a few seconds at the beginning and a few seconds just before 1C the entire roast ran at a single voltage.

• charge temperature: 178.4°F
• time to Dry End: 2:13
• time to 1C from start of roast: 5:11
• total roast time at drop: 8:03
• temperature at drop: 376.3°F
• weight loss: -14.1%

The second roast (#127) had a charge temperature about 65°F higher than the charge temperature for the first roast. Like the first roast it was given a few seconds to get the beans moving; after the initial burst it ran at 115v for around 1 minute until the BT reached 300°F. Then the voltage was reduced to 110v for the remainder of the roast.

• charge temperature: 243.4°F
• time to Dry End: 1:27
• time to 1C from start of roast: 4:02
• total roast time at drop: 6:18
• temperature at drop: 377°F
• weight loss: -14.1%

Thanks for sharing your profiles and commentary. I always appreciate your posts as they are full insight and information - tackling some of the technical aspects we poppper people face.

You mention not being certain of the actual temperatures due to your sensor being used outside its design parameters...I wonder how far off it is?

The reason I ask is between the early First Crack and a low Peak/drop temp of 377 F, I am amazed that you are not getting underdeveloped vegetal or astringent flavors in your roasts. For example, in my recent attempts to roast with lower development and peak temps, I am still coming across occasional astringency. Some of it may be due to my higher extraction brewing methods -developed around my prior darker roasts..so I can't blame the lower temps completely. Nevertheless I can't deny that since those aforementioned lower temp changes, my resulting brews are just not as consistently good as my old darker roasts.

How do your current roasts compare with prior ones? I realize you may have roasted on a different platform (not a popper)..but even so would be curious.

What sort of flavors are you getting in your roasts? Have you had good results with washed chocolate and earthy type coffees?

I have a confession to make regarding my recent roast profile changes - overall I am really not loving my new lighter roasts. The problem seems to be comprised of two issues:

-Light roast. I don't want all of my coffee roasted so light that it more resembles tea than coffee. Despite my succesful light roasts achieving a decent semblance of my goals (Panther Coffee style light roasts)...I realize that there are only certainly coffees that I want in a fruit flavored tea sort of manner. Just as one enjoys floral tea like geshas...I enjoy these lovely light tea like roasts...but there are many coffees that I can't imagine roasting this way. Add to that as often as not, I drink my coffee with a little milk..and these super light roasts do not go well at all with milk. On top of that I tend to brew with a high coffee to low water ratio...which in super light roasts can result in overly acidic or even astringent notes. While I enjoy the odd pour over coffee..it is not my preffered or usual method of brewing.
-Consistancy. I am finding that my new lighter lower roasts works great for certain coffees...especially those delicate fruiy varieties.processes...it does not work universsally. As imperfect as my old higher darker roast was, I could use it for pretty much every varietal and process with consistently good results. Does it mean it was the best profile each time..of course not, but everytime it resulted in a good cup of coffee that was enjoyable to drink. I would be tempted to assume it is just me getting used to new flavors and so forth, but my husband has really noticed a huge variation in resulting brews ever since I started this experiment. He has gone from eagerly anticipating our daily coffee hour, to being rather hesitant, not always finishing his cup...and at times has prefered to make instant. That should tell you everything you need to know about my struggles to achieve consistently good coffee.
-Caffeine...OK...a third issue..one that alone would not be a deal breaker...but on top of everything else, the caffeine is stronger as I go lighter. Overally I have managed to tame it down ...but it is still there and after two weeks I am noticing some post caffeine symptoms like warmer body temps, irritibility, and occasional thankfully low grade insomnia. Part of my husband's dislike of the new lighter roasts is that the higher caffeine aggravates his insomnia. Again if everything else were great I would just alternate between decaf and caffinated...but given the overall results, the extra ceffeine is the cherry atop the proverbial ^&%^&*$^ sundea

So for now I am going back to doing my old darker roasts but will continue to tinker with lighter roasts.

Looking over the current profiles posted on the roasting forum - on all threads - I am struck by how much roasting philopshy has changed. I am wondering if some of my struggles and dislike are related to personal preferances as well as technical ones. I would be very interested to see any of you long time roasters have noticed the changes in roast style and level in the last decade or so.

There seems to be an overall trend of shorter development phase with much lower temperatures. Back in 2004-2006 or so for example, the average home roasters was doing a 7-12 minute average roasts, with each phase being of similar length. For example a typical roast profile used to resemble the following:

1-4 or 6 minutes temp to 300 F
2-3 minutes temps to 360
4-6 minutes temps to 425-450 (depending on desired degree of roasts)

This is a very general guideline but it reflects the far more loose and primitive guidelines people worked with. I recommend visiting the old sadly now less active homeroast.org and check out the older posts in the roasting profiles. This will give a much better idea of the large variety and rather varied approaches...all quite different than today's roast trends.

What struck me at the time was the huge variety of roasting times, temperature ranges, approaches and so forth. This probably reflected the nascent evolving nature of home roasting at the time. Most of the profiles were not necessarily good as one can see by the follow up posts. Many could not be applied universally with as many terrible as good results. But all bad aside, they did represent a weath of variety -even if most came with the risk of medicore or worse roasts.

Now there seems to be a rather unviersal roasting philopshy of lighter and shorter roasting times. I hesitate to say this but it reminds me when gesha coffees took off...many older producers (especially those in South and Central America) complained about consumers wanting coffee that tasted like tea. Their comments were directed as much towards the rising popularity of gesha plantings as it was the lighter 'Third Wave' roasters. Observing the newer lighter shorter roasting trends, I can't help but wonder if these changes are merely a further evolution started by 'Third Wave' roasters and the rise more delicate fruit and floral varietals and processes. While I am seeking to roast lighter, I don't necessarily think light roasts should all taste like a floral fruit tea....

Further obscuring my quest is that most people are on quite different and far more sophisticated roasters. Put simply are most of the current roast profiles not realy applicable to the limitations of poppers?

I do not meant to criticize or put down lighter roasts...for at one time (over a decade ago), I was one of the lightest roasters in any given crowd. The difference is now people are roasting even lighter (and doing a far better job of it than I ever did). I am just wondering where the variety in roast philosphies and styles have gone? The same could be said of roasting equipment...while I love the availability of such awedome roasters and monitering capabilities..I miss having the dog bowl, popper, oven, frying pan, and whirly stove top roasters? I miss having the variety of roasting platforms because that meant that somewhere someone might have a profile that match my roaster and goals. I am not saying the old das were better, BTW..as most of us were merely guessing at what was going on during the roast, and producing rather subpar roasts. In fact I remember wishing we had better equipmnet and monitering capabilties. Rather I just miss the variety of roasting approaches...even the super dark roast dominant 'Vienna' style roasters.

Here are some exmaples :

-more heat in the drying and yellowing phases via charging/preheating empty roast chamber (often to temps close to finishing range temp)
-drawn out yellowing phase with higher starting temp but slower less steep ROR
-short development phase consisting of much lower temp range and Peak Temp. Former development & peak temp ranges varied but were univerally well above 400 F often being in the 405-450 F -depending on degree of roast...and oftne last anywhere from 4-6 minutes. Now the average development temp range seems to be 370's-barely 400F...with as many roasts finshing just below as above 400F
-shorter overall roast time. Now average roasts are around 8-8:30 minutes with darker roasts going 10 minutes or so. I remember when the average roasts was 12-15 minutes...particularily among the early gas drum home roasters.

Againt this might be a case of good roasting philosphy that is just not easily applicable or translated to poppers...hence why I started this thread.

I apologize for the ramble...and hope that non of this is taken as an attack on the current style and uniformaty of roast profiles. This is not meant to be an inflammatory attack or validation of anachronism. Rather it is meant to be a plea for help...in that the typical roast profile is not working for me (on a popper at least).

mpdeem wrote: The reason I ask is between the early First Crack and a low Peak/drop temp of 377 F, I am amazed that you are not getting underdeveloped vegetal or astringent flavors in your roasts.

As the IR sensor heats up it under-reports the temperature until it quits reading altogether. When the popper is turned on at room temperature the reported temperature is accurate I think. As it gets hotter and hotter, which happens quickly, temperatures are under-reported by wider margins. Maybe that tops out somewhere before the sensor shuts off altogether. When my end of roast drop temperature is reported as 377°F I am positive it is more than 400°F and think it is less than 450°F. If I had to guess I would guess 425°F-450°F.

If I could say with a degree of certainty what the actual temperature was at critical points I could use the Transposer Tool in Artisan to adjust the graph. Which is pretty cool.

mpdeem wrote: How do your current roasts compare with prior ones? I realize you may have roasted on a different platform (not a popper)..but even so would be curious.

What sort of flavors are you getting in your roasts? Have you had good results with washed chocolate and earthy type coffees?

My roast quality has been variable in random ways -- sometimes I have had off flavors, sometimes not, some a bit darker than I wanted, some have been uneven in color. I have struggled to get consistent results that could be compared and *knock wooden head* improved. All of that said, I usually enjoy the coffee I roast more than the coffee from local shops -- this is especially true for shots of espresso.

The 1400w Wearever™ Popcorn Pumper with a kludged IR sensor has been my roaster from the beginning. I am tempted to set up a dog bowl+heat gun system under the IR sensor and connect it to Artisan. If anything, the sensor should be significantly cooler and temperatures more accurate... sez me If I had a big chunk of cash for a new toy I would probably upgrade to a different roaster, but If roasts from the popper can be controlled and improved, it may see me through for a while.

mpdeem wrote: I have a confession to make regarding my recent roast profile changes - overall I am really not loving my new lighter roasts.

There is a well-regarded roaster in town with good seasonal selections of specialty coffee often roasted on the lighter side. I am pretty sure their coffee is excellent, but for the life of me I cannot figure out how to brew it in a way that I enjoy. I bought all of my coffee from them for a couple of years, hand-ground it at different degree of fineness, brewed at different temperatures and using different methods. The total number of cups of black coffee I finished is probably less than 10. (My primary metric for whether a cup of coffee is tastes 'good' *to me* or not is whether I drink the entire cup of black coffee.)

I have not yet learned to enjoy some of the lighter roasts and esoteric beans. I have no reason to think the coffee was the issue and every reason to think that my palate is just not enthusiastic for that yet. I enjoy coffee that is smooth with a hint of acidity and 'tastes like coffee'. Fwiw coffee can definitely be too dark for me too. I choose not to be concerned that you or I or anyone likes some coffee and not other coffee, same way I think of preferences for pizza.

My taste sensibilities are pretty simple but possibly expanding a bit now that I am roasting. Having acquired a better grinder it is easier to control extraction and balance acidity too. I eventually learned to accept, then enjoy, then often prefer acidity in wine. Maybe that will happen with coffee too.

The smell of roasted beans is a different matter. Opening a jar of coffee often releases complex aromas that could be described as fruit. The aromas in my roasted beans usually tend more toward tropical fruits than toward apples or pears, but I do not find those flavors in the cup or even in the aroma of the brewed coffee. I love that moment when the jar is opened.

mpdeem wrote:I am struck by how much roasting philosophy has changed.
...
Put simply are most of the current roast profiles not really applicable to the limitations of poppers?

To my way of thinking at a minimum you need to be wired into Artisan or similar software, have the ability to monitor the bean temperature in near real time, and the ability to adjust the bean temperature as needed. After those mechanical things are in place I believe it is more a matter of skill and experience. Are we ultimately limited by using poppers? I dunno. Could Rob Hoos create roasts with my popper to fit any profile or at least any result he wanted, my hunch is yes. Our poppers may be the equivalent of an old fashion slide rule compared to modern computers, but I guess calculations done on a slide rule resulted in engineering that got us to the moon.

In the for-what-it-is-worth category, in this out of context comment, Scott Rao suggests that people are moving more toward convection and away from conduction. Maybe we are ahead of the curve! (j/k)

EDITED: reduced the volume of raw beans roasted to 43g (from 53-55g)

Finally figured out how to get back to lighter roasts.

Turns out the culprit foiling my attempts was charging/preheating the empty roast chamber too hot. Simply starting with the empty chamber at ambient temperature has solved my issues, allowing me to drop my peak temp to 425-430 F and lower development phase temps (from 445-450 F) to 425 range.

I dug out my earliest roast logs from 2010-2012, deciding that maybe it was time to start over again. I recalled that at one time..I was able to roast light without any issues. Only in the last 3-4 years had I been struggling with an inability to roast light..yet without my roasting database, I could not be certain which changes might be responsible my current dilemma.

When I first started roasting I never charged...simply dropped the beans in at ambient temp. Since my roaster is in my kitchen, the ambient temp is rather warm (72-74F). If it was dead smack of winter and the house was icy cold, I might've preheated the chamber to 78F or 80F - otherwise no charging before roasting.

Sometime in the last 3-4 years I adapted the practice of charging/preheating the empty roast chamber. Since I lost my roast spreadsheet to a computer crash, I am not certain of the exact date....but know it was within that general time frame. I am guessing that I probably drew inspiration from roast profiles posted in forums....deciding to try charging without really considering the differences in roasting platforms. A popper chamber is much smaller than the average home roaster platform-the average roast capacity very small compared to other roasters. Add to that popper's -even when modified - tend towards a faster ROR (probably due to small roast capacity) make the popper different from most home roasters.

I am guessing that by charging to even a modest 225-275 F was causing my drying phase to run too hot, Since acid and some sweetness is developed during the drying phase, it is no wonder that my roasts were turning out bland and even slightly baked when I attempted to roast lighter (lower peak & development temps). By going darker, I am guessing that I gained some sweetness via carmelization and other roast type sweetness.

Since starting my roasts at ambient temperature -forgoing charging - I have been able to roast lighter -much lighter yet achieving much sweeter roasts with good acidity - yet not overly so - and without any vegetal or astringent notes.

Charging....how many folks charge their poppers or just start at room temp? I realize that many of you might be roasting in colder environments like a basement..so be sure to include roaster location as I find poppers are very much influenced by environmental temps.

Below is my 'new' yet old classic roast profile.

mpdeem wrote:EDITED: reduced the volume of raw beans roasted to 43g (from 53-55g)
I am guessing that by charging to even a modest 225-275 F was causing my drying phase to run too hot, Since acid and some sweetness is developed during the drying phase, it is no wonder that my roasts were turning out bland and even slightly baked when I attempted to roast lighter (lower peak & development temps). By going darker, I am guessing that I gained some sweetness via carmelization and other roast type sweetness.

Since starting my roasts at ambient temperature -forgoing charging - I have been able to roast lighter -much lighter yet achieving much sweeter roasts with good acidity - yet not overly so - and without any vegetal or astringent notes.

Charging....how many folks charge their poppers or just start at room temp? I realize that many of you might be roasting in colder environments like a basement..so be sure to include roaster location as I find poppers are very much influenced by environmental temps.

Below is my 'new' yet old classic roast profile.
image

Thanks for the above: I've been preheating my PAAR for about 1 minute-may try some roasts without a preheat and see what happens especially since you seem to be getting fully developed light roasts that way.

How hot do you let the chamber get when pre heating?

Sometimes I will preheat for a few seconds if the ambient temp is on the cool side...but only letting the chamber get to 76-80F.

I was prehating the chamber to 225-275..but then ended up having under developed flavors unless I roasted to a Peak Temperature of 450 and kept the temp range in the 440-450 F during the development phase.

Odd because I had assumed that preheating/charging would have the opposite effect....further flavor development which would allow me to do lighter roasts with lower Peak and development temperatures. Would be curious to hear what others who preheat/charge expierence....and if my problem was preheating/charging at too high a temperature (for my popper at least).

minus1psi wrote:The total number of cups of black coffee I finished is probably less than 10. (My primary metric for whether a cup of coffee is tastes 'good' *to me* or not is whether I drink the entire cup of black coffee.)

To my way of thinking at a minimum you need to be wired into Artisan or similar software, have the ability to monitor the bean temperature in near real time, and the ability to adjust the bean temperature as needed. After those mechanical things are in place I believe it is more a matter of skill and experience. Are we ultimately limited by using poppers? I dunno. Could Rob Hoos create roasts with my popper to fit any profile or at least any result he wanted, my hunch is yes. Our poppers may be the equivalent of an old fashion slide rule compared to modern computers, but I guess calculations done on a slide rule resulted in engineering that got us to the moon.

In the for-what-it-is-worth category, in this video, Scott Rao suggests that people are moving more toward convection and away from conduction. Maybe we are ahead of the curve! (j/k)

I agree completely regarding the necessity of having Artisan or other tracking software capabilities. One of my greatet fustrations is being limited to my memory when recording roasts. It is very easy to get the timing wrong. For example at the first minute of the rosat, I initially reach 200 but then the heat continues to rise a few more seconds despite turning off the heat during the first 'rest/stall'. So my written data is not accurate and is missing that important continued rise in temperature.

What happens is, over time, one ends having a large descrepancy between written data and reality. While I know that the written versions are just loose approximations...should I ever need to rely on them for precise timing and temperature - or worse -if I share them with someone else, that gap between written date versus reality might have larger implications. Again not a huge deal as I don't often share my profiles LOL...but certainly not fun when trying new roasting techniques and realizing a large portion of your recorded data does not accurately portray your current roasting methodology!

I love your 'good coffee' test. Not loving straight black coffee, I too find, that a really good roast is one that can be tolerated and even good when served straight. I realize my preferance for adding milk puts me in the minority...good to now that I am in good company!

You perfectly describe the lovely aroma of roast coffee -especially the fruit forward ones. My goal in roasting is to have the coffee taste like it smells. Nothing more disspointing in the aroma not translating to taste in the cup! Sometimes I get hungry for some fruit just smelling a good dry process fruit forward coffee.

minus1psi wrote: As a Popcorn Pumper roaster I think your idea of putting a probe at the fins to measure Environmental Temperature is smart. I am watching to see if Mary figures out a way to take good advantage of the exhaust temperature on her popper. If I install a single thermocouple it will be in the middle of the bean column, probably somewhere near the top of the bean column with a 90g dose of beans loaded. My roasts tend to be 95g-110g; placing a probe for BT based on a 90g batch provides a small margin of error.

There is a detail that deters me from installing a TC - dumping the beans for cooling. As it is now I remove the chimney, unplug the cord, and dump the beans. It is something like 10 seconds from the time I cut the power until the beans are dumped. Each new thermocouple becomes another mechanical thing do deal with before dumping the beans.

My initial plan for TCs was to make a 1/2" saddle to go across the top of the chimney and mount the TCs vertically. One of the reasons I discarded that plan was the mechanical complications of dealing with dumping the beans. Another was that it likely required that I learn to do 3D printing. I would love to know how to model objects for 3D printing but figure it will take a while, and I was more interested in roasting coffee.

I have yet to figure out a good way to capture exhaust temperature - in part because of the issues you mentioned. Still trying to figure out a way to mount thermocouplers that won't get in the way when dumping the beans.

The bigger problem is that for a good part of the roast, I stir the beans with a spoon to increase circulation.My fear is that I will inadvertantly block or otherwise alter the air coming out of the chamber. Like Inspector Clouseau of Pink Panther fame, I fear that I will excel at getting in the way!

Maybe if I am able to increase my fan power I can forgoe stirring...and then there will only remain the issue of the bean dump.

I was actauly hoping you would come up with a way LOL.

There is a recent interesting interview with Rob Hoos floating around where he is discussing, well, what Rob discusses. I guess it's got me thinking more consciously about some things like weight loss plus time/temp during 1c. In particular with my PAAR.

Regarding probe placement I'll be sticking mine in the bean mass. I have multiple probes on my Huky and Bullet. I consider ET but pay more attention to BT. For now.