Hey guys, I have the latest version of the quest m3 110v. I have erics's met and bt installed. I track in Artistan.

My first batches I roasted were 150-200g. I drink a lot of coffee and so do my friends and family, so now I am running 250g batches.

My charge temp is about 420f on my bt, most roasts I hit the turning point @1:37-1:45 and 218-224f. I have my heat between 9-10 and fan between 1.5-3 to keep my met from going over 575f.

Basically I would like sharpen my S-curve by getting to my turning point a few seconds faster and I see a lot of profiles that the bt bottoms out around 180f which seems to give better control over slowing the RoR.


I might cut back to 200-225g batches, but I figured I'd ask how other users controlled larger batch sizes on their quests.

Dont fixate on the turning point on the Quest, or your probes. I've used those original probes from Eric for years then switched to smaller, thiner probes that go in thru the sightglass screw location. It's all relative.

You'll probably be better served by charging according to what the ET probe is reading, not the MET or BT. Nothing is more variable and unreliable than the MET probe reading on a Quest. If you want to power thru your drying phase faster, charge hotter or use less coffee.

I cut back to 200g batches and it seems to be working better. Cooling is also faster, which is a big plus

I'm thinking I'll get a ET probe (have the stock thermometer in Celsius). I might switch to a Phidget to support more channels.

Would blackening the drum increase chances of scorching?

What are your charge temps for the ET probe? Just something I can use as a starting point.

Blackening the drum will increase conduction. If you're increasing the heat transfer efficiency into a roaster and not paying attention, let it get too hot, then yes, you can end up with scorching slightly easier. But you can also scorch the beans with a plain drum. The blackened drum serves the most utility when you want to roast large batches though. Anything under about 200g and you might as well not bother. The added conductivity helps a bit early on when you add a bunch of room temperature beans into a small roaster with little mass. The downside of the blackened drum is it becomes harder to shed heat and creep into post 1C development without over roasting the surface of the beans.

The main reasons I started the whole concept of blackening the drum was two-fold, I wanted to roast larger batches primarily and this helped achieve that, and second, the initial fears of too high a MET possibly burning out the elements. Jim Schulman had one of the earliest Quests, and I later followed. He had problems with the very first versions element burning out. I've ran thru hundreds of pounds of coffee in the last several years and haven't had a single problem with my elements and I've had MET's reading close to 700°F (unintentionally). The elements are very robust.

And to your ET question, about the only solid recommendation is if you were using the analogue thermometer. Once you switch to thermocouples, even standardized ones, then add in the fact that the new Quests have a small amount of fan running at all times, these things add up to very different values on on your ET ( probe depth changes the readings drastically on the Quest, the analog one just threads in and stops at the same spot). It would be safe to say that you should start out somewhere between 350-400°F, but beyond that, you just need to find where your roasts are going, in your environment, with your voltage, etc. The beauty of Jim's simplified Quest roasting suggestions is it's not focused on what a probe is telling you, but primarily sensory driven. It's highly repeatable, simple, and works if you do very small batches.

The Quest has many of it's own inherent shortcomings, but what it excels at better than almost any other roaster I've ever used, is the ability to immediately perceive aromatic changes in the roast. Because of that, you can likely get better results by using the tryer, a bright full spectrum light source and your nose, than following another persons digital profile suggestions to a tee. One of the hurdles to overcome on the Roast and Learn Together is that it's not about just sharing profiles, since they're so subjective to each roaster, but more about basic landmarks and sharing input on how you feel the roast developed using various techniques.

I have 5 different probe locations on the Quest and I currently use 4. I've found that the only really helpful reading other than a thin, precisely located BT probe thru the sightglass is a exhaust air probe that goes thru the chute and is positioned right at the exit of the drum. It's a much easier "ET" to follow because it's never directly affected by bean strikes. If you know exactly what the temp of the air is immediately leaving the drum, then you can learn better how to push and pull heat out more effectively, since the Quest is sort of a slow moving train when it comes to changing heat settings. You have to plan ahead.

Thanks Tom, you and Jim are lifesavers when it comes to using the Quest. I did buy 10lbs of the Rwanda for the Roast and Learn Together, I'm excited! We'll see how it goes

+1 for Toms explanation!