let's talk profiles & strategies

[coffeenation]

hey all,

first post in the roasting forum, roasting my own coffee commercially for about three months, at home for about a year. still consider myself a newb, but still think i make some pretty good coffee.

i'm just now being introduced to the concept of profile roasting, and i've begun meticulous logging of all my roasts, charting them in excel to see the roasting curve, etc. basically i sit in a chair and log the bean probe temp every minute on the minute, while doing the normal artisan stuff like trier checking, smelling (although all my smell goes up the stack), sight, sound. i make sure i understand if my coffees are high grown, fresh crop, etc.

my question, or i would like to discuss, what a proper roast curve should look like. i'm roasting on a diedrich IR-3. i can crank the heat up full, the steepest curve i can get to for the first few minutes is about 30F per minute till 300F. this doesn't chart to a very steep curve. my technique is also very sporadic. i go min. airflow till 300F, then throw full for a min or so, then stay 50/50 till FC. i go max airflow around FC depending on the profile i'm aiming for, but i'm not real sure what my strategy should be for burner control. i've read the time between the onset of FC and end of roast should be between 3-6 minutes. i'm not sure if i should try to plateau at the end of my roast or stop abruptly, and how to do either and for what coffees to do which. of course, proof is in the cup, but i don't have time to cup everything. it's just my wife and i, and i spend a lot of time behind the counter with customers.

just hoping to get some discussion started on the roasting issue. thanks.

 

[ElPugDiablo]

Like you, I spend a lot of time behind the counter, but I always find time to cup. So the first thing I would say is you got to find time to cup.

It's pretty hard to define a proper roasting curve because it is pretty hard to define a proper roast. Since you are logging data down right now, you can alter one variable at a time, cup the result, and write down your cupping note. Eventually through trial and error, you will find a profile for each beans, it could have a steep curve, or a shallow curve, that works for you. I know you probably have read that over and over again, but there is no real magic formula, every roaster has to discover this on his/her own.

Lastly, as Gee replied at roasters guild, it's about total energy. You manipulate total energy via flame and air flow. While max air flow does not mean cooling the drum, lowering flame will have the obvious effect of reducing total energy into the drum. You need to know what you want to do entering FC, during FC, finishing FC, and entering SC. Willem Boot suggested time between entering FC to entering SC should be about 3 minutes. I find that to be a pretty good guideline and I plan my air flow and BTU to achieve that 3 minutes target.

 

[La Crema Coffee]

Do you have the manual for your machine? If so READ IT. and you will descover some VERY interesting and enlighting data.

 

[coffeenation]

thanks for the replies.

Do you have the manual for your machine? If so READ IT. and you will descover some VERY interesting and enlighting data.

yeah, i read the diedrich manual for my IR-3. i'm using the baby diedrich, tabletop even. just startin out. i think most of the manual was written for the floor mount because none of the maintenance stuff is very clear. figured it out for myself though.

Since you are logging data down right now, you can alter one variable at a time, cup the result, and write down your cupping note. Eventually through trial and error, you will find a profile for each beans, it could have a steep curve, or a shallow curve, that works for you. I know you probably have read that over and over again, but there is no real magic formula, every roaster has to discover this on his/her own.

i've immersed myself in the roast forums, etc., etc., so the knowledge is coming along. trying the trial and error thing, still very little time to cup, but working on that. also getting a fetco extractor so that should help too.

i've read the diedrich's are really dependent on airflow for temp control. anyone know how so and in what ways? also, i can't seem to get a batch with absolutely no scorching or tipping. i've dropped charge weight and drop temp to no avail. i have to be able to produce a decent size batch on this thing or i will be perpetually roasting. good sign i guess!

 

[coffeenation]

thanks for the replies.

Do you have the manual for your machine? If so READ IT. and you will descover some VERY interesting and enlighting data.

yeah, i read the diedrich manual for my IR-3. i'm using the baby diedrich, tabletop even. just startin out. i think most of the manual was written for the floor mount because none of the maintenance stuff is very clear. figured it out for myself though.

Since you are logging data down right now, you can alter one variable at a time, cup the result, and write down your cupping note. Eventually through trial and error, you will find a profile for each beans, it could have a steep curve, or a shallow curve, that works for you. I know you probably have read that over and over again, but there is no real magic formula, every roaster has to discover this on his/her own.

i've immersed myself in the roast forums, etc., etc., so the knowledge is coming along. trying the trial and error thing, still very little time to cup, but working on that. also getting a fetco extractor so that should help too.

i've read the diedrich's are really dependent on airflow for temp control. anyone know how so and in what ways? also, i can't seem to get a batch with absolutely no scorching or tipping. i've dropped charge weight and drop temp to no avail. i have to be able to produce a decent size batch on this thing or i will be perpetually roasting. good sign i guess!

 

[coffeenation]

sorry about the double post. wanted to add my signature. vanity.

 

[vudh]

I've found that willem boot articles are very infomative and helpful.
He weigh on green beans assessment. You should know that the green bean you gonna roast is soft , medium or hard bean and what about the moisture.

The roast profile sometimes depend on the bean hardness,for example to roast soft bean , you might use low BTU entire of the roast , while the medium beans might need medium flame at the begining , high flame in the middle and medium at the end of the roast.

and I do agree that after all ,
we have to cup ..cup and cup some more.

 

[ElPugDiablo]

i've read the diedrich's are really dependent on airflow for temp control. anyone know how so and in what ways? also, i can't seem to get a batch with absolutely no scorching or tipping. i've dropped charge weight and drop temp to no avail. i have to be able to produce a decent size batch on this thing or i will be perpetually roasting. good sign i guess!

Without knowing your set up, and your gas pressure, it is really hard to say, but I recently roasted on a IR-3 at a friend's place. If you have a newer model, like the one I tried, then I disagree that it depends on airflow for temp control. The flame control is really quite good at altering temperature. On the other hand, if you have an older model, like my old IR-12, then I would say the flame control is not very good, and the roaster is under power. I have heard the same BS from Diedrich about using airflow for temperature control, but I still have not figure out how to add BTU using airflow only. One thing you should keep in mind is that IR-3's temperature probe is placed in the back and to me, a bit too high. You need to figure out exactly how much beans it take to have the beans in constant contact with the probe. If you reduce your batch size too much, your reading might not be as accurate as a larger batch. And because of that you might have more sorching and tipping problem in smaller batch. Also, have you have your temperature probe tested just to make sure it is working properly?

 

[coffeenation]

have you have your temperature probe tested just to make sure it is working properly?

my diedrich is pretty much brand new, arrived in december, installed in february. so i don't think the temp probe would be malfunctioning, although it certainly could be inaccurate. the cracks all happen at the right temps, yellowing is about right. come to think of it though things do seem to happen about 20deg later than i would expect, but i wouldn't be able to tell if it was inaccurate without testing. i'll see what i can do.

i agree with the probe placement also. i can't see the benefit of where it is placed. it seems way too high, and not where i would expect the majority of the bean mass to be. i'm sure they have their reasons, this is why i need to get to their class. broke as a joke tho.

 

[aeneas1]

i had the pleasure of speaking at length with one of probat's chief engineers who had been with the company for many, many years - he was a german gentleman and, from the sound of his voice, had more than a few decades under his belt!

anyway, he was very generous with his time - we spoke about the history of the probat roaster, the capabilities of different probat models and the technological developments in the coffee roasting industry. during our conversation i asked him for his thoughts on roasting profiles and artisan roasts - he just laughed.

true story.

 

[coffeenation]

during our conversation i asked him for his thoughts on roasting profiles and artisan roasts - he just laughed.

meaning he thinks all the talk of profiles and such is just mess? what was his roasting strategy then? i would be very interested to hear, as understanding profiles and such has been very helpful for me as a beginner grasp the roasting process. but if a seasoned vet has some other strategy i would be most interested to hear!