DavecUK Senior Member Joined: 21 Sep 2005 Posts: 916 Location: UK Expertise: I love coffee
Posted Wed May 19, 2010, 4:09pm Subject: Re: The Quest M3 Roaster
I have the UK machine and there is a rating plate on the side that says maximum 900W. I don't use the ammeter on the side of the machine, I plug into a thru plug with a watt measuring device and ensure I max out at around 900W, in fact 850 is fine for roasting..
In the video Tom stated he was setting it at 10 amps (this was around 2 minutes 15 seconds in) and potentially the roaster could be drawing around 1200W. If the US one is rated at 900W as the UK one is and I have no reason to think it wouldn't be, this could be the explanation for the short life of heating elements. In addition I have been quietly reading many posts by people in the US who own a Quest and the following points have come up.
People have been blocking the inlet hole for better warmup/heating
Trying no fan speed for faster ramp up
adding hot air to the inlet hole, some considering one post on the web where someone had done so
Comments about metal discolouration around the heating element areas.
Some misconceptions about the airflow within the roaster (especially when people had little experience with it in the early days)
Not enough discussions about warmup times
Not enough discussions about drop temps etc..
There are a few other areas, but the above are the main ones and could result in people overstressing the roaster to make it roast faster, especially for the 1st roast of the day. I do however think that the insulation mods and thermocouple mods are a great idea.
I have not modified my roaster at all from stock, but do use it in a certain way to get decent roasts and also not overstress the roaster. To do this there are some considerations for such a small roaster with a low thermal mass and designed the way it is.
Airflow
This serves 2 purposes, firstly to remove chaff from the beans and smoke from the chamber. This is achieved by the current of air flowing across the front of the drum and out of the top tube....same as blowing across the mouth of a beer glass on its side with bits of tissue paper in it. It's second job is to keep a flow of air over the heating element and aid convection currents to give slightly more even drum heating and moderate the surface temperature of the heating elements.
High airflows early on in the roast won't be helpful and will actually slow down heating, so I tend to use 3 or 4 in the early part of the roast, but I always turn up to 9 and back down to 3 or 4, in case the fan sticks....I also check the airflow manually. As the roast progresses and chaff/smoke is formed, it is helpful to increase the airflow slightly, I tend to move to 5 or 6 at this point.
To quickly moderate temperature in addition to reducing heating element power I might also turn up airflow, it can also give a fine level of control as well.
At the end of the roast, I turn the airflow up full and the heating element down to minimum and cool the beans for a few minutes .... I have seen it suggested that another batch can be dropped straight in and roasting started whilst cooling is still going on. I NEVER do this and would not advocate it being done. During cooling the airflow is directed thru the beans and there is NO negative pressure at the top tube, this in turn means NO ariflow in the inlet hole at the back of the drum. If the heating elements are on at any reasonable power e.g. 900W I would imagine they can get pretty hot!
After cooling I set the roaster back to roast mode, fan speed down to 3 or 4 and heating element power back to 850-900W. I will then drop the beans straight in even though the drum temp will still be well about the normal drop temp of say a big probat roaster. This doesn't really matter, because there is so little thermal mass that the beans don't tip as they would in a 25kg probat.
Heating elements
I use a power measuring device to ensure maximum power doesn't rise above 900W, unless it's really really cold in my workshop and I might then use 950W, but the cold air prevents things getting to overheated. These type of heating elements can take a lot of heat, but unfortunately if overheated the insulator (Mg O) melts and loses it's insulation. Standard Incoloy heating elements (as I believe is used in the quest), can take around 880C max temp and this is based on an optimal design without too many sharp bends.
Looking at the chart above and using 900W as can be seen when viewing the heating elements on the roaster, we are getting near the upper limits of Incoloy heating element design tolerances. Next time you roast have a look at what colour your roaster heating elements are at 900W and again at 1200W! Start using 1200W and I think it's asking for trouble. If faster heating is then desired the only way would be to add extra heating elements or increase the length of the heating elements for more sq metres as the max W per sq metre is fixed by the limits of the materials..
Back to the roasting, as the roast begins to near first crack I may have already moderated the ramp up and reduced power, but as 1st crack starts I will have reduced power down to 600W or lower....this is judgement call depending on the coffee being roasted and the pace of the roast.
Warmup
Remembering my old probat days and my Toper roaster, I like to give any roaster a good warmup and the quest is no exception. Fan 4, power 700 -800W and let it warm up for a good 15 minutes before I roast. I allow the temperature to max out at around 200 and then reduce to 190 for the rest of the warmup period. Even then the first roast can be a tad slower than subsequent roasts., Not warming the roaster up sufficiently will result in more power being applied to get the roast moving than if the roaster is properly warmed up.
Timings
A big commercial Probat or similar 25+ kg roaster will have a huge thermal mass and tremendous heating power. If beans are dropped at much above 160 -170C ish they can tip and when dropped the temperature of the roaster will drop but perhaps only by 20 or 30C, the roaster is able to bring the bean mass temperature up quite rapidly, much more so than the quest which experiences a massive drop. This means that trying to emulate commercial roasters timings is not easy, or even desirable. The beans will spend much more time at a lowish temperature when not so much is going on, so the longer roasting time of the Quest will equate to a similar roast using a shorter time on a much larger roaster.
In general I find the optimum roast time in the quest anything from 15-17 minutes depending on the bean being used and type of roast desired. I certainly won't throw away 17.5 minute roasts (unless it's a light roast), or 14 minute roasts. I categorise my roasts as L, M, MD, and Dark and my 15 to 17 minute range broadly runs across these roast levels.
================================
My perspective on roasting with the Quest M3, I hope it's of use to someone.....if not, well it cost you nothing. I do think it's a great little roaster and that it's unfortunate that the manufacturers seem to want to go it alone down the personal import route, rather than bite the bullet and work with distributors to gain the legal in country certifications and a decent dealer support network. I got my roaster as a test unit for review (supplied by a UK company) and like others became aware of issues in the area of certification and working with resllers etc.. The problems in the UK would be quite serious as non certified appliances cannot be sold by retailers and for people who import uncertified units, there risks other than in country support. e.g. Someone gets electrocuted or it burns your house down, there might be insurance issues. In addition the reseller becomes your voice for improvements should the unit experience any issues/problems and a company is more likely to listen to a retailer selling 100s of units than individuals.
germantownrob Senior Member Joined: 2 Dec 2007 Posts: 2,017 Location: Philadelphia Expertise: I love coffee
Espresso: Duetto 3, A Dead Oscar Grinder: Vario-W, Preciso w/Esatto,... Drip: Brazen Roaster: Diedrich IR-1, HT B
Posted Wed May 19, 2010, 6:43pm Subject: Re: The Quest M3 Roaster
Nice write up Dave, it should be helpful to the growing number of Quest owners.
My take on Tom at SM's going through so many elements is that he is putting a machine through the rigors of testing to see if it will hold up as a machine he can sell. I am sure if it makes it through testing and becomes for sale at SM's Tom will have a nice how to write up on it that will include much of what you are saying or the company will make changes itself to make it more idiot proof.
Posted Wed May 19, 2010, 8:16pm Subject: Re: The Quest M3 Roaster
TX Dave for the write up and the link to the color-temp picture.
I have been roasting exclusively with a PID and I have lost contact with roasting manually (changing power settings). But when I started, I used to crank up the power all the way (ouch!) to speed up things. If the power is all the way up, it'll damage the flavor of the beans. I set the PID to 540F (external drum surface temperature) and I get a cherry color in the heaters ( http://www.giantimpex.com/imgs/fofgingchrt.gif ). I am guessing that the temp at my heaters is ~ 750C.
The flavor of my roasts have improved a lot from when I started as I have been reading, learning, and trying different things and techniques. I think next year I'll get better.
This is what I usually do at the present time:
For best results I use a charge weight of only ~150 grams. I can put more weight but little weight makes the roaster respond faster and gives enough room for the hot air to wrap the beans as the drum turns. I think this weight gives me the best performance from the roaster as well as the "best" flavor.
My roasts are divided in three phases.
(Warm up roaster: I set the PID to 540F till BT gets to ~400F. Fan stays always maxed.)
1) Dry phase: I kill the power to PID and wait till BT goes down 350F or so. If I roast brazil I'll let BT go down lower. Then charge beans. BT reading will sink to maybe 200F. The dry phase finishes when the beans change to a light brown color. This phase could last ~ 5 minutes depending on moisture content and charge weight.
2) To 1C phase: before the dry phase finishes, about 1-3 minutes after charging the beans, I turn power to PID. My goal is to get to 300F at the same time that the beans turn to a yellow-brown color. The only time I change power is at the middle of the Dry phase (turn PID on) and the middle of the finish phase (turn PID off). The "To 1C phase" finishes at the middle of 1C.
3) Finish phase: starts at the middle of 1C and finishes with the drop of the beans. Selects roast level and flavor ~ about 4 minutes. I kill power to PID and coast at middle of Finish phase.
END
During the roast, I prepare, weight, and cull the next batch of beans. I charge the new beans when the other beans are cooling and I wait till BT drops to put power back to the PID. I usually do batch after batch except if I do Brazil (I wait till BT cools more). I control the speed of the "To 1C phase" by changing the PID set point, charge weight, and charge temperature. I never go over 460F in the MET or I'll get flavor damage. I can also speed the "To 1C phase" with the following trick. I turn the roaster to manual mode and do short max power spikes letting the MET go over 460F and bounce back to a safe reading (bellow 460F). This looks like does not affect the flavor in a bad way.
So far I've never had a problem with the roaster or its quality.
JohnMoody Senior Member Joined: 12 Mar 2007 Posts: 10 Location: New Jersey Expertise: I love coffee
Posted Thu May 20, 2010, 6:02pm Subject: Re: The Quest M3 Roaster
Excellent post Dave, thanks for the info.
I expect the next version of the operation manual will include a note about the maximum current setting one should use; it is 9.5A. Just because you can turn it higher does not mean you should ... but you won't break the roaster if you do. The elements are not terribly expensive, so just purchase some spares if you are a speed demon.
I think it is fantastic that the designer provides margin for people who have below-nominal voltage at the outlet. Using 9.5A during the run to 1C can tip the beans, so there is more than enough power for most users.
Exactly, no need for a Variac, although I still feel monitoring wattage at the plug is the best way and stick to 900W max unless it's really cold. If they put a lowish limit on the dial, then people would just by Variacs and fry the elements some other way.
msyen Senior Member Joined: 13 Mar 2010 Posts: 3 Location: Taiwan Expertise: Just starting
Posted Wed Jun 2, 2010, 6:31am Subject: Re: The Quest M3 Roaster
Dear Davec: I represent QUEST M3 to post a reply for thank you for your review regarding M3. And we'd like to clarify the last point you mentioned, since we are a small studio that produce hand-made QUEST M3, we can't apply CE certificate. However, we always use the best materials and provide very good quantity of M3 to clients. M3 is the most easy to use, durable and with the highest quality coffee roaster in coffee roaster market.
hankua Senior Member Joined: 29 Aug 2009 Posts: 204 Location: Jacksonville, Florida Expertise: Just starting
Espresso: Salvatore One Black Grinder: Pharos,Rossi RR45OD, Lido,... Drip: CCD Roaster: Yang-Chia 800n
Posted Wed Jun 2, 2010, 9:03am Subject: Re: The Quest M3 Roaster
I'm curious about the package size and weight since I travel to Taipei and Taichung to see the relatives once a year. Do you think it would fit in the overhead compartment?
DavecUK Senior Member Joined: 21 Sep 2005 Posts: 916 Location: UK Expertise: I love coffee
Posted Wed Jun 2, 2010, 10:54am Subject: Re: The Quest M3 Roaster
msyen Said:
Dear Davec: I represent QUEST M3 to post a reply for thank you for your review regarding M3. And we'd like to clarify the last point you mentioned, since we are a small studio that produce hand-made QUEST M3, we can't apply CE certificate. However, we always use the best materials and provide very good quantity of M3 to clients. M3 is the most easy to use, durable and with the highest quality coffee roaster in coffee roaster market.
No one is doubting the quality of the materials used in the Quest, it is an excellent roaster.....unfortunately there are legal issues around using non CE approved items in Europe. They cannot legally be sold by resllers and if there is a problem, people insurance companies may refuse to pay out in the event of damage or death.
You really should get the CE certificate, it's not that expensive for you to do this, and there is a large market out there for this roaster...
nobbi4711 Senior Member Joined: 20 Apr 2005 Posts: 328 Location: Germany Expertise: Professional
Espresso: Dallacorte Mini EX4 Grinder: Casadio Instantaneous Vac Pot: none Drip: French Press Roaster: Mini-500/800N drum roaster;...
Posted Fri Jun 4, 2010, 10:43am Subject: Re: The Quest M3 Roaster
DavecUK Said:
A big commercial Probat or similar 25+ kg roaster will have a huge thermal mass and tremendous heating power. If beans are dropped at much above 160 -170C ish they can tip and when dropped the temperature of the roaster will drop but perhaps only by 20 or 30C, the roaster is able to bring the bean mass temperature up quite rapidly, much more so than the quest which experiences a massive drop. This means that trying to emulate commercial roasters timings is not easy, or even desirable. The beans will spend much more time at a lowish temperature when not so much is going on, so the longer roasting time of the Quest will equate to a similar roast using a shorter time on a much larger roaster.
Please don't forget that both the probat and the Toper measure the air temperature while the M3 measures the bean temperature. That's a quite big difference in showen temperatures; air temp doesn't fall that much and not that rapidly.
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