Over the last 4 weeks I have been driving my Charge loads higher and higher. I now have roasted 3 300g loads and after tasting the coffee this morning I find the results to be very close or equal to 125g loads.

I can't say I absolutely have this down but I can achieve most any profile I want with the Quest loaded to 300g.

Some general comments:

To increase ET while decreasing BT open the bean drop and the roaster drop door (roaster empty).

I believe you need to supplement the heat of the roaster when you exceed around 260g. At least you have more flexibility with an additional heat source.

The challenge here is to be able to hit C1 between the 8:00 and 10:00 mark.

In the three loads I have roasted I have hit C1 at 7:30, 8:30 and 9:40. I have been able to see between 1:30 and 2:30 between the end of C1 and the start of C2.

I am using an Omega Data Logger, Artisan running on my Mac, Eric's Thermocouples, and a Master Pro Heat LCD Heat gun with the smallest reducer tip that fits down the tryer hole ( I just shove the heat gun in the hole with no support). My roaster is NOT insulated.

I do vary the fan speed as I would with a 125g load. Before 1C I don't exceed 6.5, 30 sec into 1c fan is set to wide open for 90sec. After that is depends on the bean and profile.

The Process:
I have had my best success with the ET running around 650f and BT at 400f when I drop the beans. I use the aforementioned technique to get these temps around these ranges. I start with the heat gun in the tryer hole with the fan set to 9 o'clock and the temp set to 400f. Once I I drop the beans I turn on the heat gun. With the temp set at 400 I don't need to worry about ill effects from the gun. What I am trying to do is get the temp bounce to happen quickly. The challenge here is getting the roast out of the drying phase in a timely manner. I watch my temps closely. To hit a C1 at 8:30 I left the gun in place running until my BT hit 235f. Leave it in longer, or increase the temps and you can shorten the roast and increase the rate of rise. Pull it at a lower tenp and you can extend the roast. What I have found is that the rate of rise curve with the gun @ 400f does not change once the gun is pulled. The rate flattens out to approximately the same slope.

I have run the gun later in the roast. When I do this I increase the temp but not over 500f.

One nice thing about this approach, when I started this morning it was 55 in the roasting room. I believe you can make up some of the ill effects of a unheated roasting environment using this technique.

Obviously, we can shorten the times between C1 and C2, or ramp up the C1 to C2 temps fairly quickly, should that be desired.

The nicest thing about using these techniques I don't have to deal with the lag we associate whit electric roasters. The gun is instant with pinpoint adjust ability.

One last thing, I have the roaster and the gun plugged into the same outlet.

From a taste standpoint, the first batch turned out fantastic. I expect these follow on batches to be excellent as well. I would appreciate it of others would validate my findings or assist in the refinement of my findings.

Nice to hear about another one using the heat gun. I'm thinking about a small hot air rework station, considering it can keep 400°C temperature and a very slow air flow. And I can't find a decent heat gun around here...

I just wonder how I'd adjust the air flow considering the double batch size.

Márcio.

Why do I get the feeling you're moving the QM3 from a Probat knockoff to a Thermalo knockoff?

Hi

Congrats on your results. I've been doing the same thing in the weekends with the same setup. The Quest M3 delivers me ~ 2.5 lbs/hour of nicely roasted coffee. The Master Pro Heat LCD Heat gun opens the door for many profile variations and load sizes, making the roaster very flexible. It is like a PID for hot air as it can control and keep its output temperature and airflow. I am very happy with that heatgun.

Cheers