Ambex YM-2 roasting temps

[pinheadmann]

Hi: I am using an Ambex YM-2, and want to see if people will share some of their roasting profiles with me. I am looking for a guideline that will tell me what temperature to drop the beans at (what temp gauge do you use?), what gas setting to keep it on, and what temp to pull the beans for various roasts.

I know that each roast is slightly different depending on the bean - I am just looking for some examples - like "Costa Rican medium roast - drop the beans at 325 drum temperature, set the shut off temp for 380, leave the gas setting at 1.5, and then pull the beans at 410 degrees....." I think some basic roast instructions would help me at this time until such time I can play with it.

Thanks in advance.
Craig.

 

[Fresh Roaster]

Those temps seem very low. How long is the roast? If you're dropping at 325F It's gotta' be dropping down to below 200F. You're going to need a lot of juice to get those beans roasted versus baked as I see it and I doubt that roaster, or any roaster can do that with a full load. From less than 200F to 410F has got to take a while but still not anywhere near the 440+F I think you should probably be shooting for. Just my two cents.

 

[pinheadmann]

yes....I do drop below 200...usually to about 170-175. Is that a big problem? I get the gas setting on 1.25 (out of 3) and the roast still finishes (430 degrees) in 13-14 minutes? If you increase the drop temp wouldn't that just make for a very quick roast of only 10-12 minutes?

 

[Coffeeexpert]

Why don't you play with different drop temps and temperature profiles and cup the results. Generally, the closer you are to a roaster's full capacity, you will require a higher drop temperature.

 

[Fresh Roaster]

yes....I do drop below 200...usually to about 170-175. Is that a big problem? I get the gas setting on 1.25 (out of 3) and the roast still finishes (430 degrees) in 13-14 minutes? If you increase the drop temp wouldn't that just make for a very quick roast of only 10-12 minutes?

You're baking not roasting... Big problem? Depends on what's in the cup at the end but I'd bet it's baked. 13-14 minutes for 2 pounds is way too much in my opinion. 4 pounds, marginal.

 

[lachris]

On my first roast of the day, I drop at around 385 on a 4lb batch. In abourt a minute and a half the batch bottoms at around 160-170 and turns upward. I think Ambex likes to see a 150 turn temp. ON a 4lb batch I set gas temp at 11columns. I believe Ambex likes to reach 300deg in about 7 min. First crack at around 380deg @ 13 mins or so. This are just guides. Just after I drop the greens I turn up the temp to around 425-435 and let her ride taking note of the time to 300 deg and the time to 1st crack. After the batch reaches my high temp setting, the gas shuts off and I eyeball it close until I reach where I want the batch to end by smell, appearance, and temp range. This is just how I do it.

In my room 2nd crack is hard to hear so I watch it close at around 425 (2nd crack time frame). My second and third batches will require less drop temps (365-355) to maintain the turn temp at around 150. Batches of smaller sizes will require less gas and cooler drop temps. My 1/2 lb sample batches will take a 190 drop temp, a 2-3column gas setting and a sharp eye. Sometime I can't hold the temp to sencond crack. They always end up finishing early - around 415-420 on the gauge.

Giver a go on a few batches. Buy some waste beans and try it several ways and write down what happens. Creat yourself a roasting log and write down temps every monute until you get a feel for the machine. I went through many many roasts until I got the hang of the machine. Wasted a lot of beans but had many good batches to use too. Aways have friends with their Mason Jars on hand to take home the waste beans - they are still better than most store bought stuff.

~ Smell the Smoke ~

lachris

 

[Fresh Roaster]

If your temps vary from roast to roast, e.g., first roast of the day versus fifth, not good. Your consistency will be totally off and the batches will most likely be totally different as they are on an entirely different profile. Sounds like your adjusting to your roaster versus making it work for you the way you should want it to.

I also think a temp of 150 after drop is REALLY low. On four pounds??? I'd be shocked if you got that cooked to anything beyond a light/medium roast in 13-14 minutes where it should probably take about 9. I'd hate to see those temps while trying to get to a French! Getting four pounds of cold mass from 150 to 430 let alone roasted dark??? Yikes.

 

[lachris]

I have found that with many roasts behind me, many notes written down, and knowledge of my machine my roasts are both consistant and predictable. I'm changing batch weight over several origins during each roast session and many variables come into play as we all know.

The GUIDELIENES I noted about are not mine...just what I was provided by other YM2 users. Probably not all, but some. Some say start at 450 and finish early - under 12 min. Some say start lower and finish a little longer. The 150 turn temp was something I was told by another YM2 user and in order to do that - adjustments have to be made each time the bean variety changes or the batch size changes, gas setting. I start at around 385 on my first 1800g batch - usually a bean that likes softer heat to start or maybe a decaf. beans that are more hard take the heat differently. sample roasting is different too.

The roast time of 9 min sounds too fast.to me. I find that depending on what I'm roasting and how much, my roast vary between 13-16 min. Time to control how I want the roast to end - at 9 mins, I suppose you can get more roasts in per hour, but that's not what I'm about. Of course, everyone does something different and for his own reasons. These are now mine. If 9 works for you GREAT. 13-16 works for me. I should mention that I do like lighter roasts - usually just to the edge of 2nd. Very consistant - enjoyable - nice results.

Sometime I'll try higher drop temps to see what happens...9 minutes...hmmm :wink:

 

[Fresh Roaster]

9-10 minutes for a light roast of four pounds? Should be right on. If you were going dark I'd say the 14 minute mark might be ok but at the temp noted I just don't think it can get there. As far as seeking consistency by playing with the variables.... Whoa!

That's a job and a half. Think of a derivative equation with no constant... I'm hard pressed to think it can be done accurately given the need for very quick thinking and some real-time calculus. Perhaps long after the fact. Be careful as it's very easy to fool yourself into perception of consistency by altering variables to get certain consistencies but missing others that can't be evaluated real time. The idea is to adjust the process to meet the profile not to adjust the elements to meet a process. I guarantee that two steaks cooked in such a way to be consistent by using different weights, time, temp, etc, are not going to be consistent unless you get lucky. Just too much going on at the molecular level. Granted, you could do it with a PC, a slew of probes and a high level of control over the processes (heat, air, pressure, etc.), but that wouldn't be very pragmatic.

Anyway, have you tried preheating your system? We prime our system (a little different than a simple preheat as we use a heat exchanger but the same concept) and it seems to level out time and temperature for all roasts as well as eliminating some other variables such as ambient conditions. I think you'd be shocked at what a few degrees in ambient temperature or a humidity change can do to a roast! I know I was after some testing a few months ago.

Still think you should try at least slightly higher temperatures. If you haven't, give it a shot. I think you'll be very pleased by what's in the cup which is what really matters, right? :wink: Let me know how it comes out!

 

[lachris]

Not to over kill this topic, but TO ME, It depends on the steak...are we talking filet or sirloin, prime rib or ribeye? I like my ribeye Pittsburg rare (flash char on the outside/rare to med rare on the inside). Filet I like thick and rare. Prime rib - I like the center cut. I guess my point is - I like steak a lot of different ways. My mom likes all her steak WELL done. But we both like steak. There are some things about coffee that we can all like, but not every one of us will be the same. That's why I find it strange that someome says XYZ coffee is excellant and not another when I can find 10 people that drink coffee everyday and none will think the same thing about the excellant cup.

With my roasting - I know I will not roast the same tomorrow as I do today. I will change as I need to in order to please the folks that pay their good money to buy my coffee. When they don't like it, I will ask why and custom roast for them as I do many. Takes time and effort but they like it and I don't mind. I can recommend what I like and that's about it.

Now - if I had commentments like stores of if I were supplying coffee shops then this would not apply. The same thing every time would be a must - what a hard thing to do when every bag of beans is a little different than the last one. Cupping becomes even more critical season to season on the same beans from the same region.

Anyway - back to the original post - Craig was looking for BASIC roasting instructions and wrote that he was "shutting down the gas at 385 and trying to let it ride to 410..."

Craig - I think somewhere in this tread you can find some basics and give'er a whirl. Let us know how it works out for you. Most of all have fun.

lachris

 

[pinheadmann]

That's all good information folks....thanks much.

I have tried the last batch with a higher drop temp (but they still go down to the 170 range when I drop them - not sure if that's desirable or not?). I also increased my gas since I was hitting the 14-15 minute roast and have now got it down to 10 minutes for a batch going up to 458 (Sumatra dark roast). They are coming out oily and dark, which is what I was shooting for. This was because somone make a comment that I was 'baking' not Roasting....so I think that was true because these are coming out better now.

I will try a few more batches on the weekend and let you know.

Thanks again....Craig.

 

[lachris]

It's good that you are getting better results.

When I commented earlier about gas settings, it hadn't occured to me that you might be using natural gas and not propane. I use propane and my settings are not the same as yours. My gauge reads from 0 to 12. For a 4+ lb batch I roast at about 11 on the guage. On natural your guage reads 0-3 I think - you are probably right on the setting.

For me, with the Ambex (flame on drum) set up, higher temps (425 and up) haven't done well for me. I tend to get bean tips that are scorched. With my set up, I have had NO trouble with scorching or baking. I hope to try a little higher drop temps this weekend and note the results - 9 minutes roasts seem pretty short to me. :wink: Pre-heat will be much higher - my 385 vs. 400-430.

Good luck and let us know what happens Craig.

lachris

 

[Shep]

Just to back up what lachirs is saying, I have been to the Ambex training seminar, and they do indeed support a 150 degree point of equilibrium and a first crack time of 13 minutes. Not saying it is right or wrong, just saying that is what they teach. I have been roasting on an Ambex for about 18 months and have not had any issue making "baked beans." I can tell you that when I heat up my YM10 to its maximum temp (450) degrees and drop 15lbs of coffee, it is always going to drop into the 150s. I do, however, agree that a lower drop temp does not allow for much adjustment or profiling of the roast.

Shep

 

[lachris]

Hey Shep - good to hear you chime in.

I tried a couple of batches with drop temps at 430 and the roast went about a minute faster. So far I can't tell too much difference. Turn points were around 180-190. Perhaps I'll give it another go with even higher drop temp - say 440 :lol:

lachris

 

[coffeejoes]

Shep
If your first crack is 13 minutes what is your finish time? Normally my 1st is between 10.5 and 11.5 with finish times between 14-15.5 minutes.