Finally! North Coffee TJ-067 - Gas Version - Page 3

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

Yes the light is factory installed...
I'm on a Mission from God!

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#22: Post by boar_d_laze »

drgary wrote:It tells me how to think about the PID in one of these.
PID acting as a cut-off at max temp only, is the rule, not the exception -- even with big deal western-made roasters. To get the PID to do more, you need a lot more hard AND software then is usually offered except at very high cost.

It's interesting, fun, valuable for automation and perhaps also for helping to create profiles which will be extended to automation; but otherwise, there's not much raison d'etre for home roasters. I think most of us are better off recognizing various roast milestones (sight, smell, and sound as well as temperature) and adjusting the roaster manually.

There are a lot of reasons to stay away from larger roasters, however many of the 500g - 1kg roasters do a great job with small loads; some going all the way down to 100g. With only a few roasts under his belt, it's premature to accept John's statement that 800g is the practical lower limit for the TJ-067 gas roaster as gospel. Time will tell.

Drop a nickel in the pot Joe. Takin' it slow. Waiter, waiter, percolator

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#23: Post by JK »

I was thinking what I did differently today..

I did not use as much air during ramp up phase, I was trying to get ROR up and I think I heated the drum to much.. Not moving enough air over drum and heating beans could be the problem..

I have to try it again Saturday..
I'm on a Mission from God!

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#24: Post by saoye » replying to JK »

My current cold start method on the electric

1. Preheat the roaster at 100% on the heat dial (I've set the PID to 350 degrees C so essentially I've got it working all the time. The PID also is linked to a warning chime but I'm never too far to need a reminder so I've just set it at a high temp to avoid stalling and the chiming).
2. Reduce the temp to 60% once the desired temperature has been reached and allow it to stabilise (total 15 minutes)
3. The air flow set at zero at this stage.
4. Just before dumping I ramp the heat back up to 100% and set the air volume to 15% for the initial drying stage. Dump the beans (and remember to clase the bean chute as it does effect ror...I have found it actually increases ror if you do not close it, so you can play around with this as another way to control your roast).
5. At about 4 minutes into the roast I lift the airflow volume up to 25%-30% and maintain until 1st crack.
6. After the first few snaps into 1st crack I put the air on full 100% all the way until the end of the roast.
7. At rolling 1st crack I reduce the temp dial to between 70% to 80% depending on where I am in the profile
8. Coast into 2nd crack playing with heat dial to try to maintain a given roast profile.

Some variations depending on the roast profile but in general this is my template which has proven to work for me and my particular roaster. There are no two roasters identical in response and given yours is the gas one then I'm sure the controllability is also with much less lag.

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#25: Post by JK »

I just finished the Brazilian coffee in the profile and I couldn't be more pleased..
The beans are some of my oldest about a full year old and they tasted great..
Not bad for my third roast..
I'm on a Mission from God!

smite (original poster)

#26: Post by smite (original poster) »

This weekend I spent some time going through and trying different size loads and managed to get surprisingly great looking results from a 300g load. I also did loads in the 400, 450, and 500g. They were different beans all roasted to a desired profile varying by bean. The 300g load was the last of very nice COE Mexican from earlier this year that I roasted to a C+ and it smells great so far. I hope the flavors come through in the next couple of days.

I also managed to do a 800g load of Ethiopia barely past C yesterday. It smelled really good so I could not wait and ended up pulling a shot of this as an SO in the afternoon today and the result was an amazing dark chocolate citrus orange flavor with a toffee, honey finish.

The 500g was a very nice Colombian I have used before and I took it just to start of 2nd crack, much darker than my personal preference at the request of a friend.

The 450g was a non funky Sulawesi that I like to roast on the light side, brought to C+.


The colors and shadows for the beans may not be as clear as they could be as I am taking these shots in less than optimal lighting conditions using my phone in my office just this evening.

Last but not least here is the close up picture of the wiring to the PID as requested.

By the way the beans I had previously roasted taste really good so far, and have displayed a flavor profile consistent with other roasts I have done with the same beans.

Edit: Sigh, now my office smells like fresh roasted coffee, which of course means, I now want some. The trouble is its almost 11pm and I have a very early busy day tomorrow.

smite (original poster)

#27: Post by smite (original poster) »

I will end up posting some of the roast profiles eventually. I just need to get my data logging set up.

One odd thing that I have noticed that the temp displayed on the PID using the stock thermocouple is pretty far off. It seems to be displaying around 30-50F lower than what I am expecting. The reason I am putting such a wide range is that the current stock thermocouple is placed too high for BT and yet it is also too low for an accurate ET.

I will be interesting to see what my K type displays for BT when it is up and running to see how far off my range really is. I might also see if I can dig up some details on how to adjust the PID so I can get a more accurate reading with what is currently installed.

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#28: Post by JK »

My first probe temps where 50° low..
I changed the shape into a L with the tip facing left..
I'll take a pic tomorrow but its about a inch long on both legs and my 1C today was around 385°F and before it was 345°F with 700G batches and a little higher with 800G

Here are two FC roasts I did today one was 800G and the other 700G and I still had a minor tipping on the creases of the 700G roast..

I'm on a Mission from God!

smite (original poster)

#29: Post by smite (original poster) »


Thanks. The pictures would be interesting to see. Are you planning on using the stock probe at all and reconnecting it to the FOTEK PID when it comes in?

In terms of the tipping I have noticed that once the roaster has reached its point of being thermally stable I can seriously cut back on the gas right before and immediately after drop and still get a good turn. This way I manage the time of drying mostly with the blower, especially for smaller loads.

Not that you can tell by the pictures I took, but by taking this approach I have no tipping on any of the smaller runs I did this last weekend.

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#30: Post by JK »

The coffee I'm roasting is coming out fine but I have to cut the heat for a minute before charge and still get a fast turn and a fast dry but then I have no heat for ramp up and too much heat for finish..

I'll have to try lower changes around 300-350°

I have no PID temp just my ET and BT probes
I'd like to be able to see the PID temp.
I have a few weeks I guess before the new PID is here..

If your doing small loads I'm not so sure you will get a good BT
Most of the beans are on the lower left side of the drum wall..

What I did was use a 3" long probe..
I filed/ ground the crimps that hold the wire off and pulled the wire out..
I then cut the tubing with a cutoff wheel or tubing cutter..
I then drilled out the tubing from the threaded mount ..
I then bent the tubing to fit..
6" long probe might help so you have extra tubing to experiment with..
I had a piece of metal with the radius I wanted abd used a drill inside the tubing 1/8" from the bend to stop it from folding in 1/2 and bent a little and pulled drill out a little till I had the 90° bend.. Buy two probes as it took me some practice and ordering from China takes weeks.. These probes were only $5-$6.. Temps looked fine doing two 500G batches today..
I'm on a Mission from God!