YM-2 Drop temps

[lachris]

Got the used YM-2 this weekend - She's red and shinny!

Can someone make some recommendations for pre-heat and drop temps for 1lb, 2lb, and 4lb batches. I realize there will be some variance based on bean origin, but some help here would save a lot of lbs of beans from being scorched or baked. I have recieved some good guidlines but would like some additional real life input from the forum - I suppose one could go to Florida for the class at Ambex...

Thanks for any input!

 

[dutchcoffeenut]

Starting temps

Hello Chris, glad to hear you found one. do you have it all hooked up? the temps I use is preheat to 395/400F and drop the beans, then wait until they reach equilibrium and turn the gas down to about 5 (oz/2inch) unless you have a smaller batch then you may want to turn it down to 3.5 or even less.
Then when you reach 200F I go down another 1. (or to 4 (oz/2inch) or 2.5 for smaller batches. What is your target roast time ? many go for rather short 12/14 minutes roasts (time is money?) I find I get better body in the cup by going 17/18 minutes. Let me know how it goes for you, Good luck.
Ed

 

[lachris]

Hi Ed - yes I'm on my way. I worked out a good deal with Victor Mondry in Madison, WI. He was really nice. I drove up with my father and picked it up. We roasted some on his Joper and on the Ambex. I bought about 110lbs of beans and drove home. Yours was the set up I really wanted but just could make it all work out - I'm sorry for that.

Temps: on 4+lb batches I start out around 380 or so then as batches continue I drop that a little. I think Ambex recommends a turn temp at around 150. With a full drum, these temps work about right. This I gathered from fellow poster and roaster SHEP. When I visited him, these temps worked very well. I think their (Ambex) idea is to reach 300 at 7min and first crack around 13min. I finish up around 16-19 min depending upon the bean and roast level targeted.

With the smaller 2lb batch, I'm struggling with reaching the turn point temp. Mass size is too small to carry the temps down and then back up at the same rates and ratios. Experimenting hasn't produced the answer yet. I do know that you can't hold temps very well below 230 without large temp swings from the gas coming on and off. A small burst of fire and the temp swing with less beans is pretty fast. By the time the gas turns off temp has moved 10-25deg. I guess the point is to not burn or scorch the beans at drop time. Too high a temp and too small a batch size will result in that happening. Not good for the bean.

Thanks for your post.

Hope all is doing well - hope you are getting more rest.

lachris

 

[Fresh Roaster]

This is a good argument for automation once you get to the actual roasting process. Let a computer and/or process/control automation regulate the roasting process and this becomes a non-issue. :wink:

For instance, if I want to set my preheat to X and let it drop to .5X it doesn't matter if I have six pounds or one pound. The computer makes all of the necessary adjustments to hit the targets in a requested time frame. To do that manually with all of the potential variables to any degree of precision is a hefty task.

Without automation controls I'd have to say that you will have to rely on trial and error until you find some sort of system of benchmarks. Problem is that even when you define the benchmarks they can change on you in a flash based on environment, crop, etc. But, you can keep your fingers crossed and hopefully any variances will be within acceptable margins and tolerances such that it does not affect the roasts too much. Good luck with it though. Happy roasting! :grin:

 

[lachris]

Two weeks into it and I've learned so much - LOADS of FUN!!! PLus really fresh coffee...

 

[dutchcoffeenut]

Hi Ed - yes I'm on my way. I worked out a good deal with Victor Mondry in Madison, WI. He was really nice. I drove up with my father and picked it up. We roasted some on his Joper and on the Ambex. I bought about 110lbs of beans and drove home. Yours was the set up I really wanted but just could make it all work out - I'm sorry for that.

No need to apologize, it was crazy to ship at those prices. I'm happy for you that you found what you wanted. good luck my friend.
Ed

 

[lachris]

ED - how does your chaff can connect to your roaster? I cannot tell from your photos and I can see from some that it sets on a frame sof some kind, and in other photos it appears to be floating in air. Does it attach some where? :?

Did you manage to sell your set up yet? I would have loved to just moved your whole building with all the stuff to KY - nice set up. :grin: