So I had some DP Ethiopian coffee sitting around (got from SM about 6 months ago) that I revisited a few days ago with odd results. I'm currently flying with only my Compak K10, so I was only able to sample it as espresso, but it had a very annoying bitter aftertaste that wasn't unlike rubber.

Coffee was 5 days post roast and showed no signs of excessive crema. The profile was pretty generic, with a 195c charge temperature, a little more than 4 minutes drying, 1c around 8.5 mins, and dropped around 219c with about 1.5 mins of development.

One weird thing that happened during the roast though -- during 1c, there was a lot more smoke than normal. The ET was around 220c I think, and the coffee does have a lot of chaff, so I assumed it was getting ready to ignite -- could this smoke be what I tasted?

Last time I roasted this bean was on my Quest, and I don't see the taste of rubber in any of my cupping notes Any ideas?

dogjamboree wrote:...
Last time I roasted this bean was on my Quest, and I don't see the taste of rubber in any of my cupping notes Any ideas?

I notice you have different equipment, but I had rubber one time in a bean. The next time I went to roast, I noticed that the chaff bumper plate was missing its two little rubber guards. "Oh, that is what was giving off that horrendous taste..."

I had a natural processed Ethiopian that smelled in the cup just liked it smelled in the bag- and that was not good. In 13 years of home roasting I never experienced that aroma. I roasted it twice, the first time in a pre-roast blend. The second time as an SO, and that time darker than I usually go. I'd call it Full City, possibly to a "+," and let that second batch rest for four or five days. Still had that aroma and taste. I contacted the seller (one who is often recommended) and he said that was how it was supposed to be. I threw the rest away.

Randy G. wrote:I had a natural processed Ethiopian that smelled in the cup just liked it smelled in the bag- and that was not good. In 13 years of home roasting I never experienced that aroma...

Container contamination?

We had a PNG on the cupping table two weeks ago. In the greens, it had an off-smell I could not identify. I brought those to the table as well and passed them around. No one had ever smelled anything like it. It had an aroma of a dry cleaning agent. The fragrance was nothing like anything I experienced at the SCAA's green defects course.

Some residual aroma, bad, was in that container. Greens took it on. I am convinced of it and shared that with the broker.

These greens were vacuum sealed in mason jars when they arrived, so I don't think it's coming from the container. Scary to think part of my roaster might have come loose in the batch, but there was a lot more smoke then expected, so who knows...better double check

I pulled a couple more shots from the problem batch this morning to confirm it wasn't just a couple rogue beans, and they tasted the same. The previous and subsequent batches tasted fine, however, but they were different beans altogether.

Don't you wish sometimes that there was a simple answer? I guess this if it were easy everyone would be roasting world-class coffee and none of us would be here...

frank