Pot marks on beans

[IndCoffeeOfPA]

The last couple roasts I have noticed some of the beans come out with pot marks on the beans. The little pieces are ending up in the trey below the burners and some stay in the drum after we pull the roast. Usually seems to happen when we do a 1/2 batch of beans, (ie roasting 10lbs on a 20lb roaster). Roast time of course a shorter than a full batch, around 10 to 13 minutes, depending on damper settings and pull temp. Anyone else have this issue with their roaster?? It is an Ambex Ym10 running on Propane.

Thanks in advance!

Eric

 

[thewilliams1]

I'm pretty sure what you're seeing are scorch marks from the oil that beads out of the bean and comes in contact with the drum, which explains why lighter loads produce more. How's your lighter roasts, and whats your charge temp for the half-batches? Try a lower turn temp and a slower ramp maybe?

 

[ourcoffeebarn]

Season the drum more if the roaster is new. Charge temp is too high is another cause of "tipping", the little discs that look like small paper punch cut outs.

 

[thewilliams1]

Correct me is I'm wrong, but doesnt tipping only refer to the tip of the bean... the umbilical matrix where the density of the bean is different from the rest. http://farm3.static.flickr.com/2650/400 ... f7aff5.jpg ... Whereas Scorching or Facing is what Eric is describing. Both are caused by the same variables... too high of a charge or a hot turn-temp (among other variables like air-flow) but scorching is from the oil actually blowing out a pit and scorching the bean and isnt limited to a specific area.

 

[ElPugDiablo]

Looks like a quaker to me.

 

[thewilliams1]

naw.. a quaker doesnt pick up the color of the rest of the roast because of its undeveloped sugars... it doesnt carmalize.

that jpg may be a bit quakerish.. but thats not the point. it's from Thompson from sweet maria's.. showing the tip.. maybe a premature bean, but thats besides the point.

 

[ourcoffeebarn]

Call it what you want, but a lower charge temp and a smoother roasting heat gain and maybe a slight slow down between cracks should correct the troubles.

I try to achieve 2 slowdowns during the roast. 1 when 1st crack starts, around 365 to 380 degrees and if a dark roast another when finishing.

When I get my graphs to chart right I will post some screen shots.

 

[IndCoffeeOfPA]

Thank you very much for the advice. I will try some of the suggestions and report back.

 

[topher]

Geez you just want the world don't you...first we get your roast even and now you want us to fix this?? It's called pitting...what are your roast times, drop temp and finish temp? I assume you are doing late night roasts :wink:

 

[ourcoffeebarn]

Geez you just want the world don't you...first we get your roast even and now you want us to fix this?? It's called pitting...what are your roast times, drop temp and finish temp? I assume you are doing late night roasts :wink:

Topher Who are you asking? Eric or me?

A re seasoning may help also.

 

[topher]

I was busting Erics chops...

 

[IndCoffeeOfPA]

Roast temp: watlow at 420, pulled at 450

Drop temp: 420

time, 13.5 min

Amt, around 10 lbs.

Yes Topher, sneaking a few roasts in the evening.. ha ha

Hope all is well!

 

[topher]

Eric if you want call me tomorrow after 10ish if you get a chance...if not I am around all day after 10 and all day friday. :wink:

 

[ElPugDiablo]

naw.. a quaker doesnt pick up the color of the rest of the roast because of its undeveloped sugars... it doesnt carmalize.

that jpg may be a bit quakerish.. but thats not the point. it's from Thompson from sweet maria's.. showing the tip.. maybe a premature bean, but thats besides the point.

Sorry, I thought that was Eric's picture.

 

[BeanGrinder]

I concur with Topher - also the speed that your beans are roasting is probably too fast. So - I would ask what kind of roaster you are using, what is the capacity (3k, 15k etc) and how large is the typical batch. Size of the batch in relation to the roaster capacity will effect the evenness of the roast and the speed of the roast.

I may have missed this info in the post, but I'm looking back and not seeing it.