Quest M3 or M6?

Discuss roast levels and profiles for espresso, equipment for roasting coffee.
Pressino
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#1: Post by Pressino »

I am looking to get a new roaster for home use and pretty sure I want to buy a Quest but unsure whether to get the M3 or M6.

I've been home roasting for years and have managed to get very good roasts out of the Behmor, though not for the smaller (1/4 to 1/2 lb) batches, for which my air roasters (i-Roast and popper) seem to work better.

I do like the drum roast compared to the air-roasts, which is why I'm looking for a more capable drum roaster (my preference being electric rather than gas). I don't need or want any "programmability" as I prefer to observe and manually adjust the roast as needed, nor do I require roasting more than 3/4lb at a time. 300 to 450g batches would be the maximum most of the time, but I also would like to be able to roast down to 120g on occasion.

I like the slightly more compact M3 but am not sure if it can handle a 400 to 450g batch. I know the M6 can, but I worry that it would not be suitable for roasting 100 to 150g batches.

Any advice to help make a choice between the M3 and M6 would be greatly appreciated :!:

edgndg
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#2: Post by edgndg »

I typically roast 200g on my M3, have occasionally pushed to 250g. I don't think there is any way to get it to go to 450g. Otherwise the quests seem to check all your boxes. I have been very happy with mine (also upgraded from Behmor). But batch sizes definitely smaller.

Nunas
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#3: Post by Nunas »

I had an M3 Mk-2, and now have an M6. The M3 easily will do 250 gram batches. I pushed mine once to 400 just to see what would happen. It struggled. It's happiest at 250 grams. My M6 is happiest at 400 to 450 grams, even though it is rated higher. Either one will do smaller batches, as they are identical in build; the M6 is simply a bit longer with slightly bigger heaters. Have a look at my Quest manual here https://www.dropbox.com/s/upzbg8u8ktlet ... 1.pdf?dl=0 It's getting a bit dated, but should give you some good information.

Pressino (original poster)
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#4: Post by Pressino (original poster) »

Thanks Nunas for answering my question of whether or not the M6 will be able to roast smaller batches like the M3. And the M6 (I saw the M3 and M6 at Sweet Maria's) doesn't much bulkier than the M3. I've also read your Quest Coffee Roaster Handbook and learned a lot from that.

Based on all that, it looks like I'll get the M6. Thanks again.

Pressino (original poster)
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#5: Post by Pressino (original poster) »

Just wanted to add an update to this old thread and to thank Nunas for his advice regarding the M3 and M6. I decided to get the M3 after all, mainly because its batch size better fit my roasting needs. I got the M3S with an 01/2023 manufacturing date, which I suppose makes it the latest version. I've been using it guided by Nunas' excellent instruction manual, and I've reached the point that I can get excellent roasts in my preferred range of City to Full City+.

There was a significantly steep early learning curve, which would have been a lot steeper without Nunas' manual. First batch was way over-roasted, which I realized was due to the much greater thermal mass of the Quest compared to my Behmor or air roasters. This feature is the main reason the Quest can roast back-to-back batches so efficiently. The increased thermal mass/inertia changed the thermal response time and required a different roast temperature control strategy, and made it critically important to dump the beans as soon as they reached the target roast level, since even with the heaters turned off keeping them in the drum even a minute longer would lead to serious over-roasting. I should have been able to anticipate this issue from the discussion in the manual, but a few sentences added the manual might make it clearer.

I got two of the Quest thermocouples from the manufacturer and put one in the BT slot. I've been using the ET analog thermometer, but plan to replace it with the other thermocouple, mainly because I want to monitor F rather than C temps and eventually would like to use computer logging. I've got a Fluke 289 that would probably do the trick, but for dual temp monitoring I think the Mastech m6514 would be easier to set up for dual channel use.

Beanz
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#6: Post by Beanz »

The Quest is a robust and reliable roaster you will get great roasts once you become familiar with it. The Mastech is a good choice for getting started and will interface with software when you are ready to follow that path. I would suggest if you are going to run two probes that rather than measure ET you should consider a probe between the drum and the outside case, MET. It will allow you to "look ahead" and predict where the temperature is heading and take any action to guide things in the direction you want. The MET probe will be thinner and uses a different thread size. There are plenty of modifications detailed in other posts. A couple of useful ones are:
1 Run a power meter in line so you can monitor power to the roaster and use the settings you record for future roasts.
2 Insulating the outside of the roaster with something as simple as a fire blanket to increase efficiency.
Enjoy your new roaster

edgndg
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#7: Post by edgndg »

If you decide you want to put a thermocouple in the bean chute hole for MET as suggested above LMK. When I had access to a drill press I drilled a couple extra of the screws. They fit the coffee shrub thermocouples (intentionally tight).

Pressino (original poster)
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#8: Post by Pressino (original poster) »

Thanks for the suggestions. I'm going to measure the ET and BT locations using Artisan and the dual channel digital thermometer for a while to see how it goes and perhaps later add a probe in the MET location to see if there is a real benefit doing so. No problems for me to drill a hole in the M4 cap screw for the Coffee Shrub thermocouple probe, but of course its threaded bolt sleeve diameter is too big to fit the M4 hole. I'd probably just use a 1/16th probe, which would be even more responsive. Given the thermal inertia of the M3, which I view as a good feature of this small roaster provided one knows how to take advantage of it, I wonder if measuring MET in a responsive way would be more useful than measuring ET.

I know there are differing opinions about the relative benefits of measuring MET versus ET, but I have no definite opinion yet. Just did another roast on the M3 and it's clearly doing a good job.

dcbrown1
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#9: Post by dcbrown1 »

I also wavered between the M3 and M6, and did get a new M3 based on my typical roast size (actually shifted from 250 grams on my previous Hottop 2k+ to 200 on the M3), and the fact that back-to-back roasts work well. I roast in my heated garage (usually at about 45-50 degrees in winter) and had two issues. 1. Deal with smoke ventilation. 2. Drum insulation. I worked on some solutions that others here may find helpful. I built a somewhat crude stand and enclosure incorporating two duct fan boosters. Worked fantastic. And, based on some older posts here on drum insulation, scored some awesome (but pricey) high-heat automotive exhaust insulation that was exactly the right width. To secure in place I bought a piece of aluminum trim at the hardware store, cut it to to 7", drilled some holes that aligned with the existing holes in the drum area, got some slightly longer screws to accommodate the thickness of the aluminum and it worked great. After a bit of acclimation time, roasts are coming area very well. I obtained two probes from Molly direct, since coffee shrub for some reason consistently doesn't have them in stock. I shifted to the M3 from a Hottop 2k+ and am loving the simplicity. I'm now roasting more on senses versus just mechanics. I did notice a big difference in stability and heat retention post installing the insulation. What a great little roaster.

Pressino (original poster)
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#10: Post by Pressino (original poster) »

Very neat set up, with the dedicated smoke exhaust cabinet. Don't think I'll need to insulate the drum housing in my environment, which isn't as cold as yours and at least here the main "problem" (if it can be considered a problem...and in some ways is actually a benefit) is that the machine retains heat perhaps too well and takes a fair bit of time to cool down when the heater current is decreased or even turned off.