Dustin,

It seems like a lot of guys who bought Santoker 500s were either pushing to shorten time, increase load or both. I don't know if it's got anything to do with consistency, but... consider trying a more laid-back profile. Ramp looks alright, but -- compared to how I roast in another "classic drum" roaster -- your Charge to TP, Drying and Development are rushed.

Not promising anything, but if you allow the inside of the bean to keep pace with the outside you may get better consistency; you'll also get coffee that holds on to its fruits and personality as it ages a great deal better than you're probably getting now.

As a sort of generic, try:

• A charge weight in the roaster's sweet spot, which IIRC, is somewhere in the 350g - 400g range.
• Charge with gas off or very low. You want 75sec - 90sec from Charge to TP;
• Use intervals of 5:45 - 6:00 to EOD (or 300F), 3:45 Ramp (to 1stCs), and 3:15 Development (to mid C+);
• Start with low airflow (but enough to keep negative pressure in the drum) during the interval from Charge to (anticipation of) 1stCs, then
• Increase to a relatively high airflow through Development.

Rich

Hey Rich,

Ive done about 1500 roasts now with the Santoker and I feel pretty confident about the profiles I choose. So Im not really looking for overall profile shaping recommendations. Im more just curious if this ever happens to others. Makes me what to take a look at my probes again... hmm...

For the record this is an experimental coffee. The processing is different from any other coffee in existence. So that really doesn't help the situation.

the RoR track differences might be giving useful feedback. There are some quite distinct differences to work with.
But also have concerns about these Ethiopian super blended super lots. Extreme size and shape differences as well as many different varietals. Granted they have been well sorted for quality beans, well processed and packaged better in shipping. But are a pain to strategize roasting. And even more challenging with consistency. Also seems hard to believe they can blend so well that we can't detect differences within a bag or lot. My roaster roasts about as evenly as is possible but can still find differences within a batch of these top ethiopians. I have a few good ethiopian lots in the vault from '05-'07 that had less of a mix than now seeing.

Used to mix/blend grains for feed on a large farm and it isn't easy.

Storage of greens should always be a major concern.

Hey Ed,

At first I was looking at RoR, and hoping that was the issue. Im still not sure, but Im leaning towards that not being the case. These beans are not uniform in anyway, that for sure. But ive had this happen on other coffees as well(washed Geshas and washed Ethiopians).

I think I may have sorted it out though. One of the probes I installed moves a millimeter or two sometimes, which is enough to throw off the temp a couple degrees and possibly ruin a coffee that needs a very specific profile to work... I dont know for sure thats it, but I did some experiments tonight and hopefully tomorrow ill be greeted in the morning by some delicious coffee.

In case anyone is cares, it was not a wiggly thermocouple causing my problems. I still have no idea what the hell is going on. Though I do think it has something to do with my bare probes I'm in the process of changing them out right now.

All turning point tells is how sensitive your thermocouple is.

Ya, I think rich was referring to if they were consistent from batch to batch. Mine were a little off in the graph I posted. I may switch out my bare probe for a sheathed one

dustin360 wrote:Hello all,
Curious to know if anyone has these troubles from time to time as I do.

I often have to deal with this problem.
I believe that here play the role of two powerful factors:
- Humidity air
- The temperature in roastery

In other words, roasting is highly dependent on the microclimate in roastery.

I think so

Hi Dustin

Just to share my own limited experience.

I realize on my Hottop (even though you use a different roaster), even when I do not warm it up with the same routine, I get different results. For instance, most of the time I would go through a roast cycle with no bean, wait for the roaster to reach 428F (whatever max temp is on the HT), let it cool down, then restart another roast with beans. If I get lazy, I'd always end up hitting myself because I will not get the same results.

Other factors to consider. When you mentioned the bean doesnt really crack, or hard to hear the cracks, and you're roasting Ethiopian, first thing that came to mind is the inconsistent bean sizes. Then I look at your approach to first crack, which is very slow. Lastly I look at your development time past start of first cracks. Only 1:00. These factors are all working against you when you want to achieve consistent roasts. Some of the beans are just finishing first cracks while some have not even started first cracks. Usually for a Ethiopian I like a bit more energy (but not too much, depending on who you talk to), going into first cracks. This is especially true when your end-of-roast metric is based on time, and not temperature. Your end-of-roast temperatures between the two roasts look very different to me. I'm not sure if the weight loss is also inconsistent?

Not sure if this helps.

You are absolutely correct,

I too am no expert, however I am of the opinion that any roaster 1 KG or less is extremely sensitive to the external conditions, temperature, and perhaps humidity, at the time of roast. One cannot expect the same results from a small roaster in ambient temperature of 80 degrees and 70% humidity versus 68 degrees and 40% humidity.

I always record the temperature of the city, the actual temperature of the roasting area and the humidity for each roasting session.