I purchased some decaf Brazil Bourbon Santos and Sumatra Mandheling from a roaster that I had not tried before, which I blended 50/50. I have poured 5 shots thus far, which I have been drinking as cappuccino. The coffee has a burnt taste.
The roast is apparently City+, at my request. However the oils that show on the surface of the beans (and the width of the bean crack) make me think that they might be Full City or even Full City+. The beans are 2 weeks off roast.
I have been using a 14 in, 26.0 to 26.5 to 27.0, out (1:1.85 to 1:1.92 ratio) in a 15g IMS basket.
I tried: a) reducing the temperature from 95C to 94C. b) grinding 0.5 coarser on my Niche. As a result the coffee tastes not as heavily burnt as initially, but still has unpleasant burnt flavours. And it seems to lack other coffee flavours and strength. I could go to 93C and even coarser but suspect that the result will not be great.
I am about to throw out the coffee. Well, I might wait, and try the Ethiopia Natural Sidamo and Brazil Bourbon Santos decaf blend that I also bought from that roaster and see if that also tastes burnt. I also have one of their proprietary blends to try. Hopefully they have not over roasted all 😡
I find that it is challenging to find roasters that know how to roast decaf. I have found afew but have rejected many.