Quest M3 Roasting Instructions

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

Now that I have a year of roasting under my belt, I feel fairly confident giving my M3 roasting recipe. Others with experience will have different recipes. So let this thread be posts by fully experienced users saying how they actually use the roaster. Please keep posts on topic, i.e. nuts and bolts instructions, not modifications, theories, repair or buying advice.
  • I roast back to back roasts from between 100 and 200 grams. For the first roast, I preheat the roaster to 205C on the front thermometer, as if I had just finished a roast.
  • After I drop in, I keep the trap door open, the heat at 5 amps (110 volts i.e 550watts), and am either cooling the previous load, cleaning the chaff collector, or have the cooling door closed and the fan completely off. If the cooling door is closed, the fan needs to be off so the vapor comes out the trap door, and isn't sucked into the rear (see next item).
  • I have three action points after I start a roast. I set a timer at 3 minutes 30 seconds at the start, and after I make each choice, I restart it to warn me for the next choice point.
  • After the first 3 1/2 minutes, I check the bean temperature. When the beans reach 150C (it happens roughly at this point) they are steaming and smell wet. At some point in the next minute,. the vapor will get a lot less steamy, more hay-like, the bean temperature be between 150C and 165C. Then I go to the next stage. I crank the heat and fan to full, and reset the timer. If you want a toasty/malt flavored roast, use a longer ramp by setting the the heat lower, 7 to 8 amps, and the fan to 6.
  • 3 1/2 miunutes later, the bean temperature will be getting up 185C. When the temperature hits 190C, I cut the heat to somewhere between 5 and 8 amps and the fan from 4 to 6 (more heat, more fan). The actual level depends on how light and fast I want to roast. The 5 amp/4 fan setting setting gets me a 4 minute City roast, the 8 amp, 6 fan setting for a 4 minute FC+ roast. At this action point, I also check the MET and will cut the heat early if it gets out of bounds. However, if you follow this recipe; you will rarely need to worry about the MET
  • 3 1/2 minutes later, I look for the right point to end the roast. For cupping roasts, I sniff, and wait for the all the sharp vinegar and cutting chlorine like smells to fade away, and for the roast to smell sweet. For brewing roasts, I go a bit further. When the smell is right, I start checking the tryer, and make sure the bean surface is smooth, and the flat side, slightly bulged out. For roasts stopped just ahead of the first pops of the second, I wait to get roasty, spicy, smoky smells (i,e, dry distilliates) and cut the moment they occur. For darker roasts, the audible progress of the second crack is my guide.
  • Dropping in the follow-on roast after a dark roast gets you a hotter roaster. But I don't find it makes a big difference. It takes 3 to 4 minutes for the beans to get up to 150C regardless.
Jim Schulman


#2: Post by Bob_M »

Hi Jim, and thanks for posting this informative summary. I have 2 Questions about the Quest.
On page 32 of the main Quest thread you said "...the fan should never be run below 4, since the flow cuts out completely at 3 to 3.5..."; instructions that came with mine from Coffee Shrub say to determine minimum "blow" by observing fan blades while turning fan nob from off to clockwise and noting when detail of blades begins to blur, and that this should happen between 4.5 and 5...this is where mine is set meaning my fan settings are 1.5 off from yours...I would like to know if the various fan settings are all over the map or is mine an outlier. It's certainly easy enough to adjust it. Second, at what room temperature are you roasting?

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another_jim (original poster)
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#3: Post by another_jim (original poster) »

It is very good advice to check for the zero point of the fan; it never occurred to me that they could be different on different roasters.

But your request for exact numbers tells me I haven't been clear enough. I think there may be too much variation between roasters for the exact numbers to be meaningful. I should have written no fan/no or minimal heat to start; full fan/heat in the middle, medium fan/medium heat to finish, regardless of the numbers.

The major points I was trying to make are:
  1. different kinds of events mark each roast stage: visible steam from the trap door changing to a hay-vapor for the end of the drying stage, 190C bean temperature for cutting the heat prior to the first crack, and either roast smell (cupping roasts), bean appearance (light brewing roasts), roast smell again (light espresso roasts), or finally the sounds of 2nd crack progress (dark roasts) to end the roast,
  2. each stage takes roughly 3 1/2 to 4 1/2 minutes, and that roasts should run roughly 10 1/2 to 13 1/2 minutes.
I recommend these roast stage signs and timing milestones, using whatever heat and fan settings that will get them for you.
Jim Schulman

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#4: Post by rama »

At what temperature roughly do you reach first and second cracks with your instrumentation? That would be helpful in determining what your reported temps are relative to other's setups.

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#5: Post by benm5678 »

I'm curious too Jim, at what avg temp do you reach 1C? To help understand how early you start cutting heat.

I tried a few times, and couldn't get those steps to work on my machine. Ramp stage got very long, since when I reached ~300F and only then increased power and full blown fan, it really made MET drop, and took it a while to recover. And when approaching 1C, maybe i needed to cut it earlier, but assuming your BT is roughly the same as mine, I got a very fast 1C, reaching 2C in about 2 min.

I have the new style 2mm drum, not sure if it makes any difference. In any case, I understand we'll never get exact recipes & probably there are various ways to achieve good results. FWIW, here's a video of my roasting strategy if anyone is curious and has 12min to burn :) ...I think it does show how *extremely* effective the controls are on this roaster, as I can get it to match a previous roasts many times. It's only when i don't pay attention or have different starting temps that I may lose it:

Is it "Digital Roasting or way to consistency?" :lol:

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another_jim (original poster)
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#6: Post by another_jim (original poster) »

I get 1st crack at 195C to 200C. As I stated, I reduce the heat at 190C, and time the roast finish from there.

Your ET sensor will always drop for a moment when cranking up the fan, since the airflow affects it more quickly than the heater. But the amount of heat you transport to the beans is maximized at the highest airflow and heat setting.

If the new instructions from Quest are right, you can go up to 6 amps heat during the no fan drying stage. This may make for a faster rebound.

If the finish is too fast, nothing is stopping you cutting the heat even more.
Jim Schulman

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#7: Post by Dieter01 »

I knew from my previous roasts that I was not going to be able to get a 3.5 min drying but decided to try following Jim's instructions anyways... I used 180g of Costa Rican coffee. Here is what I got:

Drop-in at 205C, 2.5 Amp / no fan (220V M3 version with new, thinner drum).
At 129C bean temp: Changed to 4 amp / 4 fan.
Reached 150 degrees after 5:54 min.
At 156C bean temp: 5 amp / 8.5 fan (which is full throttle on both).
At 173C bean temp: Reduced to 4 amp due to high MET.
At 190C bean temp: Reduced to 3 amp / 5 fan.

If I hadn't changed anything during the drying phase it would still take me more than 5 min to get to 150C. I did a second test with 4 1/3 amps and minimum fan (still 180g weight) and managed to get to 150C in 3 min 50 sec. Keep in mind that 5 is full throttle on my machine...

Are we using the same amount of beans? Is performance different??

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

Trap door open, no fan for the drying phase. Set the heat with an eye on you MET. Make sure it doesn't go above your safety limit, but keep the heat high enough so it doesn't nose dive either. If you pay attention to the steam, you will see that below about 140C-145C is a dead time, the beans are not really drying much at all. The steaming starts at around 140C, so you want to get your beans to that point ASAP.

My roaster is insulated, and I never thought it made all that much difference. But never got this much of a nosedive in the MET, so it could be that the drying phase is where my insulation makes a difference.

{Metacomment} I think this thread is drifting off course. I use the M3 as an old fashioned manual roaster, basing all my decisions on the bean's appearance and smell (as well as a general preference for 10 to 14 minute roasts). The time and temperatures are not what this recipe is about, they are milestones for checking the bean and making manual decisions. (The Met is also used for safety, since the recipe pushes the thermal limits of the roaster.) If you want to base the roast on time and temperature profiles, you will need to use a different recipe, rather than modifying this one.
Jim Schulman

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#9: Post by Dieter01 »

I did leave the trap door open, yes.

I am not looking for a specific profile, but at the same time I am curious why my results appear so radically different from yours. With the same amount of power and no fan it takes me significantly longer to get to 150C. I have not found a good way to drop in a new batch while still cooling the old one. Perhaps I am too scared to crank up the temperature without the fan running, i don't know...

So far my appraoch has been the following:
- Cool down previous batch. Once done, re-heat until desired drum temperature.
- Drop in (with current beans I have mostly done this at 210C on BT probe). I use minimum fan setting (mine is 4) and power depending on mass loaded. Could be 3.5 - 4.5 amp (European model).
- Reach 150C in about 4+ minutes. Once the smell is no longer damp I max both power and fan (usually just before 160C).
- In not too long I will reach my MET and reduce the power to keep it stable at this value, still with max fan setting.
- In the 180-190C BT range I will decrease power (and fan later if needed)
- At 197-200C BT I try to be at 250-260C on my ET probe (which gives me the rate of rise I prefer during 1C).
- From this point I usually set the fan to minimum (4) and adjust power depending on what beans I am roasting and whether its for espresso, Aeropress or cupping. If the temperature gets a bit high I might increase the fan for a short while or open the trap door as well. For espresso I run the first batch just into 2C to get a BT referance. The following batches I use this temperature as a warning when to start smelling the exhaust and eject when it gets smoky (just short of 2C for a slightly brighter cup). For brewing or cupping roasts I am not accurately able to use smell yet so I eject based on what I see in the tryer.

In other words, the road to 1C is based on a "profile" and is similar for all coffees. Even though I crank up the temperature when the damp smell is dissapearing I don't think you would go seriously wrong by always cranking up the temperature at 160C either... Or perhaps I am wrong? After 1C though the approach needs to differ based on desired end result and I make decisions based on what the senses are telling me. I am sure those of you with more experience change your initial approach more. Delicate beans probably need more careful treatment. Some hard beans could perhaps take more initial heat.

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#10: Post by another_jim (original poster) »

If the trap door is open, the fan has no effect. If you drop in after cooling, you lose a lot of heat from the drum, and this may make a time difference. Finally, 3 1/2 minutes is when I start looking, I wait until the steaming stops to go to the next ramp. My roasts run from 10.5 to 13 minutes using this recipe, depending on the delays at each stage. If a coffee is very wet, it may end up taking five minutes to dry.
Jim Schulman