Stages of coffee roasting - pros and cons of longer/shorter durations

[Kealia]

I'm fairly new to roasting on our Behmor 1600+, having bought it in October. I know there are a number of new folks as well so I thought some discussion on the various stages of roasting would be valuable.

So, thinking about drying, Maillard reaction and development stages....let's start with the most basic of questions: Are those the right terms for the 3 stages?

Since that was an easy one, let's start by focusing on this:
What are the pros/cons of a longer vs shorter drying stage? Meaning, assuming I stop two roasts at the same point in the roast (let's say Full City), what would be the difference between roast #1 that had a drying stage that lasted 4 minutes versus roast #2 that had a drying stage that lasted 6 minutes?

I've done some searching and wasn't able to find much more information other than descriptions of the stages, but little actual discussion. If there is a resource out there and anybody has links, please do provide them.

Hopefully this can be an on-going discussion about stage lengths and pros vs. cons.

Cheers.,

 

[Kealia]

Hmmm, maybe I am the only one thinking about this. That can't be!

 

[MerlinWerks]

Hmmm, maybe I am the only one thinking about this. That can't be!

There is a four part series at Sweet Marias, part three covers manipulating the drying (yellowing) phase.
https://legacy.sweetmarias.com/library/categories/roasting-theory

I've recently been watching the "Roaster School Online" produced by Mill City Roasters which provides a lot of good info on each stage.

 

[Kealia]

Excellent, thanks for the references. I'll check those out then come back with any discussion points, etc.

Cheers.

 

[Kealia]

Ok ,so far I've listened to/watched the first three episodes of the Roaster School Online and it's great. I can see where some people will feel that it is complete overkill, but I like getting this view of what's going on. It's interesting to see the similarities to home brewing (beer) as well. Actually, now that I say that...this reminds of reading Palmer's "How to Brew when I started making beer.

A couple of interesting things I've heard so far:
1) The time it takes to get to the yellowing phase makes no difference on the taste profile of the coffee. I understand why you want to control your charge, temps, etc. to get repeatability....but it's good to know that if you take 5 minutes to get to yellowing on one roast and then 6 on the next it won't automatically change the taste of the coffee. Of course, there are downstream effects of that in terms of temp and time, but I'll hold off on that for now.

2) Dense beans will accept heat faster than less dense beans. I would have thought the opposite, but I was a psych major not a biology/chemistry/physics major! I can see (at least in my mind) a good reason to go slower on certain beans, in the beginning, to ensure proper heat absorption without scorching or tipping. I'll keep this mind for future roasts.

I'm looking forward to watching a few more and then reading up on the Sweet Maria's links, too.

 

[Kealia]

Very interesting reading.....
3) Stretching out 1st crack or the time after first crack doesn't add to the sweetness but can add more of a syrupy mouthfeel.
4) Perceived acidity can be altered by stretching out the drying phase and by stretching out the time after the end of first crack


This is exactly the type of information I was looking for.
Is anybody here applying this information to their roasts?

 

[Ruint]

I have been trying @Kealia, to implement some of those principles, but I would say that my successes would be limited just by the roasting method I use. I have very little complaints with using a bread machine/heatgun because I have certainly had some fantastic results with finished roasts...Some of the manipulations methods though, I feel would be better suited for use with a drum roaster, whether it be electric or gas...because the control over heating is that much more controllable.

 

[Kealia]

Understood, and thanks for the response. My wife and I started with an air-popper and we were blown away with how good the coffee was! That led to a purchase of a Behmor 1600+ and I have a tendency to want to know as much about the process and levers that can be pulled as possible.

I'm like that with my homebrewing, too. I may not choose to pul each lever, but it's nice to know what they do so if I/she/we decide we want a particular roast to be more or less of something (sweet, acidic, etc.) I'll know how to make an adjustment.

She's much more of a "set and forget" person. I want to push all the buttons

 

[Inkleg]

I want to push all the buttons

Speaking of pushing buttons........I'll see you in Nashville.

 

[Kealia]

Speaking of pushing buttons........I'll see you in Nashville.

Well played, sir.

 

[shelly_belly]

I found this, here... https://forum.homeroasters.org/forum/viewthread.php?thread_id=2189

0 to 300F (or yellow) is drying phase:
Try to get bean temp to 200 F as quick as reasonably possible then taper off the power from there to hit yellow somewhere between 4 and 5 minutes. Too fast brings 'grassiness' in most coffees and 'ashyness' in some low altitude beans such as Brazils, Kona etc. Too slow will flatten or mute the flavors.

300F to first crack:
Too fast brings higher percieved sharp acidity, slower brings nuttiness, too slow brings 'baked' flavor

First crack to finish:
Too fast tastes underdeveloped, flat. Too slow through this stage can also bring about a baked flavor.

From 300F on the beans should NEVER drop in temperature, always increasing.

 

[Kealia]

The only problem with that information is the general nature of statements like "too slow" or "too fast"....there is no reference to actual times, percentage of total roast, etc.

 

[Atalanta]

I was roasting for a local coffee house and each bean was roasted a little differently. It was a gas-fired roaster. The ethiopian I would increase the gas until the beans reached about 350F and then drop it down until first crack. The goal was to extend the crack time to about a minute and a half. At the end of the crack, I would drop the beans to cool. None of the beans were roasted into the second crack. The Kenyan was dropped when the first crack would get very energetic.