So I'm getting better at controlling my Quest M3 roaster, but still not able to roast light enough for my liking (city or just shy of it).

With most of the beans I'm roasting, FC comes at 200c,or sometimes a little sooner or later. By the time FC is underway, I've generally slowed things down enough that the BT ROR is in the neighborhood of 4-8 degrees / minute, which means by the time FC is done, the beans are darker than I want them to be.

I've read more than once that one should never stop short of finishing FC, but is this always true? I've found that if I let my ROR get too low during FC, say around 2 or 3, the roast stalls and cracking will not start again even if I get the BT back where it belongs.

My roasts taste fine in the end, but they they're always more like city +, and sometimes there are even a few small spots of oil showing (does this correlate with a particular roast degree, or does it depend on the bean?)

The good news is my friends are enjoying all the coffee I'm sending their way, as I only drink enough to make tasting notes.

Any ideas / ruminations would be much appreciated!

Frank

Dry processed beans tend to get a darker color.
If you are doing a slow roast profile the beans will also look a bit darker as well.

What is the total time of the roast, length of the drying phase, start of FC?

Kfir.

Attached is an artisan profile of a recent roast --
Beans: Guatemalan (washed), 200g
Drying Phase ends 3:42 at 137c
FC starts at 9:36

This is one of my roasts where my BT ROR got down around 3 for a little bit and FC only lasted about 2 minutes.

Well I am guessing that the "ET" is actually "MET" since it shows relatively high temperatures.

I would try to shorten the roast a bit, try to get to first crack a bit faster (lets say a minute less) and pull the roast 2-2.5 minutes after it starts.
Also I think that the drying phase is a bit long for 200g, I would suggest not more than 3-4 minutes.

How much airflow you are using during each phase ? the air can help to shorten the roast and to restrain the MET from getting too high if you apply more heat.

Kfir.

Thanks Kfir -- if I remember right this was my first roast of the session, so drying took a little longer than subsequent sessions.

I've got my fan off during drying (with bean hatch open), and I have it set between 5 and 6 during the development phase. I've found that any higher and I end up slowing the ROR by introducing too much cold air.

You're correct, my "ET" is actually "MET." I'll try seeing if hitting first crack faster changes my final roast degree. To do this I'm going to need to reduce my charge weight, as I'm basically moving as fast as I can without getting my MET too high. I was hoping that seasoning my drum would allow me success with 200g charges, but maybe not...we'll see.

Frank

You can try to use more heat and more air than 5-6 and it probably won't stall and also restrain your MET.

I would also try using the fan on low during the drying stage.

Kfir.

So I played with this some more, and I'm still having the same problem. My most recent experiment, shown below, has me reaching first crack by 6:14 with a healthy ROR in the ramp up to FC of 15+. Development time during first crack is 2:47 with a ROR of just about 6, which finishes the roast at 213c, right as FC was complete.

The end result is still a medium roast, around City+. When I compare to beans from Stumptown and Heart Roasters, mine are darkest, followed by Stumptown, then Heart's (all are washed Guatemalas).

I had an opportunity to talk to Wille from Heart this morning, as I was sipping my americano and poring over some used brewing equipment they were selling. Maybe it was rude of me, as I've heard some roasters don't like to talk about their trade, but I asked him about my dilemma -- specifically, below what ROR would he consider a stall, during first crack.

His answer was pretty definitive -- "around 6 degrees" (per minute). Now that I think of it I didn't get a chance to ask him if he was talking celsius or fahrenheit, but I would assume celsius, being that he's from Finland originally.

So if I add up all of the conventional wisdom I've read on various boards (here and elsewhere), and gleaned from talking to people, I don't see how I'd end up with a lighter roast than I'm achieving if final temperature is the primary driver of roast degree.

Everyone says to allow at least a couple of minutes for roast development after first crack, many say more than 3 minutes. With first crack happening pretty consistently around 196c-200c, and keeping ROR at a minimum of 6, that puts me in the neighborhood of 212c+, which I know from past experiments is too dark, for my tastes at least, with this particular guatemala (Sweet Maria's Finca Cabrejo).

Is there anyone out there with a Quest M3 who's successfully roasted light (City or even lighter) who's willing to post a profile? I get the feeling that most home roasters are roasting quite a bit darker than I'm shooting for, but please, prove me wrong with some profiles!

dogjamboree wrote:So I played with this some more, and I'm still having the same problem. My most recent experiment, shown below, has me reaching first crack by 6:14 with a healthy ROR in the ramp up to FC of 15+. Development time during first crack is 2:47 with a ROR of just about 6, which finishes the roast at 213c, right as FC was complete.

The end result is still a medium roast, around City+. When I compare to beans from Stumptown and Heart Roasters, mine are darkest, followed by Stumptown, then Heart's (all are washed Guatemalas).

I had an opportunity to talk to Wille from Heart this morning, as I was sipping my americano and poring over some used brewing equipment they were selling. Maybe it was rude of me, as I've heard some roasters don't like to talk about their trade, but I asked him about my dilemma -- specifically, below what ROR would he consider a stall, during first crack.

His answer was pretty definitive -- "around 6 degrees" (per minute). Now that I think of it I didn't get a chance to ask him if he was talking celsius or fahrenheit, but I would assume celsius, being that he's from Finland originally.

So if I add up all of the conventional wisdom I've read on various boards (here and elsewhere), and gleaned from talking to people, I don't see how I'd end up with a lighter roast than I'm achieving if final temperature is the primary driver of roast degree.

Everyone says to allow at least a couple of minutes for roast development after first crack, many say more than 3 minutes. With first crack happening pretty consistently around 196c-200c, and keeping ROR at a minimum of 6, that puts me in the neighborhood of 212c+, which I know from past experiments is too dark, for my tastes at least, with this particular guatemala (Sweet Maria's Finca Cabrejo).

Is there anyone out there with a Quest M3 who's successfully roasted light (City or even lighter) who's willing to post a profile? I get the feeling that most home roasters are roasting quite a bit darker than I'm shooting for, but please, prove me wrong with some profiles!


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Based on my experience and the info you and the roaster gave I would assume he was talking F for ROR. From start of first to finish of first crack is about 18f rise for me and I like to do that in 2-3 min depending on how bright I want the roast. For city roast I like to slow down the roast approaching first crack, this IMO helps the beans come into first crack around the same time while coming into first faster tends to stretch out first crack a little more and I will still have beans in FC while many are getting to City + which is nice for a city + or a full city roast.

The Quest is a versatile roaster. That means you can make it go fast enough or slow enough to screw things up. If you work at it, you can do both in a single roast.

Not all beans are cooperative about making the "right" noises as they go through 1st and 2d crack phases. It's possible you're getting the chemical, size and taste changes even if you aren't getting the sound effects.

My suggestion is to stop chasing some supposedly "ideal" roasting time; and that includes an ideal time to or through a particular roast landmark like end of drying or interval between onset of first crack and and drop. There are no ideal times, only good or bad results.

On the other hand, don't throw away your watch. There are some useful, normative time ranges. Your total roast times don't look that long to me.

On the other hand, don't throw away your thermometer either. Your charging temp looks very high for a Quest size dose. A too high dose temp can show up as a rate of surface coloration change which exceeds the expected the rate of internal chemical change. In other words, a too-high charge temp is something which can produce a very dark color at a landmark like onset of 1st crack. And that's the case here.

You'd also expect some other manifestations like wrinkled skin and tipping. Do you get those?

Try reducing your charge temp to around 175C.

And don't feel like you have to hurry through the drying phase. Slow (or at least slowish) is fine. A gentle drying phase encourages sweetness. Don't worry about speeding up the drying phase unless your roasts taste "baked."

BDL

I'm not sure what "wrinkled skin" means -- I do get bean surfaces that aren't smooth sometimes, but generally only if I stop the roast too soon after first crack. I don't think I'm experiencing tipping, but there are sometimes some small areas of the bean that are darker than the rest. I asked a local roaster if the beans looked tipped or scorched, and he said no, but who knows. When I look at the chaff after the roast, it's consistently a golden-yellow color, with no signs of being burnt, but I'm not sure if that's indicative of anything.

I'll try starting with a lower charge temperature and see what happens. I've tried ending the drying phase both by smell and temperature, without any noticeable difference in the finished product. Sometimes my nose tells me to stop 5-10c before the 150c benchmark that seems to be used for the Quest.

I'll also try slowing down the roast even more during first crack. 6 Fahrenheit works out to around 3 Celsius in the range of temperatures where first crack starts. I've done at least a hundred roasts over the past few months and gotten a decent sense of how to get the thermocouples to cooperate -- too bad the beans still aren't listening!