Hello all. I've been a long time reader of these forums but am must now posting. Just got a new Quest M3 . . . thanks SAS!

Here is where I make the obligatory statement about how I've read and read and read all the Quest M3 posts on this forum and others and still have questions! Glad thats out of the way.

I've primarily been trained on a commercial roaster, so I thought I would be a pro at the Quest. However, now I'm finding out how much more information I'm getting with the Quest. I have BT, ET and MET thermocouples going through a Phidget 1048 and being read in Artisan. So here are some (quest)tions . . . sorry, I'll avoid those puns in the future:

1. In my commercial roasting, at FC, I'm used to dropping the gas to about 1/4 or sometimes cutting the gas all together depending how fast I'm approaching FC. I then crank the Airflow to max and allow the heat being released from FC carry me most of the rest of the roast, adjusting gas accordingly. So when I try this on my Quest . . . cranking the air from 5 to 10 and dropping the power to around 2.5 amps, my roast almost immediately stalls. The simple answer is to not drop my amps, but I guess my question is why is there this difference between my commercial roasting and Quest roasting? I saw someone else on a thread who was doing exactly like me and experiencing the same thing, but I now can't find that thread, so maybe they can PM me if still around.

2. Similarly, in commercial roasting I could just give it some air and almost immediately see the BT ramp up. With the quest, I seem to see a minor drop followed by a recovery, with no ramping up of BT, which makes me think that the amps are the only thing I can use to control BT. Is this right? Thoughts?

3. This is more of a roasting question. I am really struggling to determine a point to drop my roast. In my commercial roasting we shoot for a certain time range, w/ a development of 3 min. Regardless though, we drop based on a final BT, to the point where we don't even really look at the beans. Because we roast dark, and I like lighter roasts, I figured I could just knock 15F - 20F of those drop temps to get more where I like. So I did this yesterday on my quest and its darker than we roast at the commercial place! So now I'm wondering about how reliable using final BT is in getting a certain roast. I was also using this flyer I got from Sweet Marias that says city-city+ is dropped at 415-435. I dropped at 415 and my coffee is way too dark. Also, using final BT never seemed like it made a whole lot of sense . . . lets say I hit 1C at 10 minutes . . . if I hit 430F @ 11:45 on one roast, but then I hit 415F @ 13:00 on another roast, I would think the longer roast would be darker. Wouldn't an extra 1:15 have a greater impact than 15F which is only a 3.5% temp difference. I'm having trouble forming this question, but maybe someone can help me out . . . I'd totally be up for articles/threads on this topic if anyone has links.

4. Whenever I take out the Trier during a roast, I see a recorded dip in both ET and BT. Is this stalling my roast? I only take it out for 5 seconds max.

5. When in Artisan, I hit the buttons to record 1C, E1C and Drop. However, after stopping the program and saving, these disappear from my graph and I can't figure out how to get them back and visible! Any help on this?

6. When people on here talk about development time, does that begin when 1C begins or ends?

Thanks to anyone with any input!

I roast on a Huky 500 which is in the same league as your Quest, at least when compared to a commercial roaster. The reactions are somewhat similar to what you describe, although I have no experience with commercial roasters.
There is one major difference though, which I think explains our mutual problem. Just about any professional roaster weighs in at 200-2000 pounds while the Quest (and the Huky) is in the 10-20# range. There simply is no mass in our machines to build up and hold heat like the huge cast iron monsters.
Now, the difference between your machine and mine is that mine run on gas, which gives quicker response than electricity. Also, adding airflow to a gas machine can turn the efficiency of the burner up a bit (affecting the oxygen/gas mix to produce more heat), while it only cools down an electrical machine.
About thermocouplers, they often read different. You have to calibrate/compensate to reach your results. While my FC often starts at 198C, which is right on the money, I have to break a bit early and check the window and not the computer/temp in the ending stages, cause if I go for a given temp my roasts get a bit dark too.

There is an article on the Artisan home page, "Controlling a Hottop Roaster with Artisan: The Basics v6 (PDF) by Barrie Fairley", which in detail describes how to set up Artisan. Even though it seems like aimed at the HotTop owners audience, it describes all the steps in how to set Artisan up for recording and displaying most of what is needed for any user.

The development time is agreed to be from the start of first crack.

Ask ultramafic orange for his recipe for the quest
Preheat to the higher settings he suggests (i interpret preheat temp as for BT meaning MET will be higher)
Keep fan on low throughout
Dump based on BT using ultramatic orange's reproduction of Sweet Marias bean temps for different roast levels

This worked great for my Quest though note that i painted the drum with black bbq paint to improve heat transfer. A 227g charge worked great. Next i will do 300g.

I am trying to use Scott Rao formula of energizing the system with lots of preheat and then having a declining rate of rise over time to drop. I find Artisan has some great predictive tools to help you decide when to tweak your heat a bit here and there to keep that curve smooth but no big changes

First crack happened when artisan BT said it would. When i approached BT i wanted for the drop based on roast level from the SM chart, I killed power and blasted air to get chaff out and dropped the beans.

Espresso today poured gloriously, amazing crema and richness throughout.

edtbjon wrote: There is one major difference though, which I think explains our mutual problem. Just about any professional roaster weighs in at 200-2000 pounds while the Quest (and the Huky) is in the 10-20# range. There simply is no mass in our machines to build up and hold heat like the huge cast iron monsters.
Now, the difference between your machine and mine is that mine run on gas, which gives quicker response than electricity. Also, adding airflow to a gas machine can turn the efficiency of the burner up a bit (affecting the oxygen/gas mix to produce more heat), while it only cools down an electrical machine.

Oh man, I think you're so right! Of course Oxygens affect on a gas burner is different than an electric burner. I'm a little embarrassed I didn't think of that.

Thanks for the replies, I'm going to keep experimenting, and reading. I'd love to hear more on questions 3-5 if anyone has any more thoughts.

I've been away from a decent sized keyboard for a few days. Here's my thoughts on it FWIW.

Roasty wrote:1. In my commercial roasting, at FC, I'm used to dropping the gas to about 1/4 or sometimes cutting the gas all together depending how fast I'm approaching FC. I then crank the Airflow to max and allow the heat being released from FC carry me most of the rest of the roast, adjusting gas accordingly. So when I try this on my Quest . . . cranking the air from 5 to 10 and dropping the power to around 2.5 amps, my roast almost immediately stalls...

With no significant thermal mass to draw residual heat from and a fan design that is specific only to the Quest, this phenomena you described isn't a surprise. That would be a textbook way to stall a roast on the Quest. If you get better at controlling your heat level, you'll not have to rely on the goofy fan design to draw heat out of the drum. I've profiled countless roasts where I barely move the fan setting once I'm hitting 1C, and letting Amp changes guide my post 1C development time and finish. This is highly dependent on charge weight and other preceding factors like charge temp, density, moisture content, etc, etc..

Roasty wrote:2. Similarly, in commercial roasting I could just give it some air and almost immediately see the BT ramp up. With the quest, I seem to see a minor drop followed by a recovery, with no ramping up of BT, which makes me think that the amps are the only thing I can use to control BT. Is this right? Thoughts?

That minor drop and then recovery is the fan pulling the heat off the probes, but from what I can tell, it has no effect immediately on the roast. The air being moved by the fan is not pre-heated by the elements in the same way that air is heated by the gas of a commercial drum roaster, so correlations are not possible between the two. It's one of the main weaknesses in the Quest. It's it's own odd hybrid design that doesn't work like a normal roaster should in terms of air flow. With some roasts, I consider the fan nothing more than a chaff remover and focus most of my attention on Amp settings. The key thing to remember when making mental comparisons of the Quest to any large commercial roaster is that in the Quest, changes on what your thermometry is telling you happen quickly, but you can bounce around in a million directions getting confused trying to track where things are going. All your temp readings are extremely dependent on where you locate them, even depth wise in the stock position.

Roasty wrote:3. This is more of a roasting question. I am really struggling to determine a point to drop my roast. In my commercial roasting we shoot for a certain time range, w/ a development of 3 min. Regardless though, we drop based on a final BT, to the point where we don't even really look at the beans. Because we roast dark, and I like lighter roasts, I figured I could just knock 15F - 20F of those drop temps to get more where I like. So I did this yesterday on my quest and its darker than we roast at the commercial place! So now I'm wondering about how reliable using final BT is in getting a certain roast. I was also using this flyer I got from Sweet Marias that says city-city+ is dropped at 415-435. I dropped at 415 and my coffee is way too dark. Also, using final BT never seemed like it made a whole lot of sense . . . lets say I hit 1C at 10 minutes . . . if I hit 430F @ 11:45 on one roast, but then I hit 415F @ 13:00 on another roast, I would think the longer roast would be darker. Wouldn't an extra 1:15 have a greater impact than 15F which is only a 3.5% temp difference....

The smaller you go in drum diameter, the nearly exponentially faster finishing times you get in the roast. This is a lesson straight from Boot and it bears true. You can drag out a roast much easier, and slowly on a large commercial roaster. On something small like the Quest it's much, much more difficult to do without stalling out. As far as the tail end of your question about temps and times, it's only a guess at best and you should trust your tastebuds more than what a probe is telling you. Coffee is one of the most complex substances we regularly ingest, with hundreds if not a thousand different compounds and molecules being created, destroyed or altered at any given moment. Anyone claiming to have certainty as to what is or isn't in your coffee at a specific given time is deluding themselves. So this ultimately leaves the roaster to judge by what they get in the cup, not steer their profile based on what someone says a time graph or temp reading should be.

Roasty wrote:4. Whenever I take out the Trier during a roast, I see a recorded dip in both ET and BT. Is this stalling my roast? I only take it out for 5 seconds max.

Yes it caves the temp quickly. I've noticed no deleterious effects from doing so. The only thing it seems to do is make your graphs harder to properly interpret, because you'll see a flatline or massive dip on your BT. One way to avoid this is to use a very thin bendable probe and run it thru the sight glass screw, where you can really bury the beans well with it. Then, don't charge too low a mass. I can pull samples on a 200g roast and up, without much interference. Any lower, or on smaller dense beans, and I see this start popping up.

Roasty wrote:6. When people on here talk about development time, does that begin when 1C begins or ends?

Begins vigorously.

Thanks everyone for the replies, very helpful! I'll keep experimenting!