Hottop tipping/scorching

[brendogs]

Brendogs, irrespective of your charge temp.....what is your turn temp?

p.s. Col.... as per thread title Brendogs is using a Hottop.

My drop temp today was 140C and the turn temp was 70C at 1 min. These are taken from the BT where I do all my datalogging with the hottop.

Last week I tried a higher drop of 170C with an 80C turn at 1min. When I drop I turn the heat source down to 50% with the fan on half speed to try and steady the first rise so it doesn't gather too much momentum into the drying phase.

[chokkidog]

Brendogs, irrespective of your charge temp.....what is your turn temp?

p.s. Col.... as per thread title Brendogs is using a Hottop.

[Col3]

Hi brendogs,

What machine are you using? Sorry just saw hottop in the subject. The rest of this is not very useful tgen eh. To give background I use an insulated corretto with cover and a bosch 'green' heat gun w/ digital input temp. Also I'm reasonably new to it all as only just ive cracked 15kgs (pun not intended ). My current charged weight is 500g.

I experienced a few tipping batches and found the biggest impact was air flow rate. I now leave it purely on 2 and just adjust the temp.

To check if it was the issue I have varied my charged temp between 100 and 209 degrees, tried higher input temps with lower air flow rate and ran initally fan 3 to 100 - 150C. Only thing that caused tipping for me was putting on fan 3.

Hope that helps.
Col

[brendogs]

Hi there,

I just wanted to put it out there and see if anyone else is getting the same results as me.

As per title I've found lately that all my roasts have had signs of sometimes significant tipping. As I've been trying really hard to avoid it in the past few weeks I'm getting mixed results. I started lowering the drop temp ranging from 130C - 160C to see if I was going to get a different result. I've tried extending the roast and giving it a much more gentle rate of rise.

Today I dropped in at 150C with some Brazil Pulped Naturals using a charge weight of 160g to try and not over load it and I probably got my best results in regards to not so much tipping probably around 30% of the beans have signs of tipping (but this is more than enough to taint and ruin the cup). The profile today was basically 150C drop temp, extended the drying phase, had the airflow on from the middle of drying phase to the end of the roast to make sure there was sufficient airflow. I'm ejecting just before 2C.

I've tried extending the roast and trying to be more gentle on the RoR, 18-20min roast time.
I've tried to be a little more aggressive with higher airflow total 12-14min roast time.
I've tried both of these with higher drop temps of 180C down to 130C.

I have a feeling the beans are spending too much time on the drum and scorching, I am thinking of removing the drum and fabricating up some new stainless fins to try and replicate the Behmor style agitation fins which I think work great.

Any thoughts? Has anyone else encountered this problem.