Hello all,

I recently returned from a trip to Panama. While I was there, I went on a coffee tour of Cafe Ruiz (whose coffee won the first "Cup of Excellence" IIRC). While being truly amazed and humbled exploring one of the farms, I really got a kick out of the rejects being sold to Folgers and the like.

However, I was able to watch them roasting their coffee and they took 20 minutes to reach what they called "European roast" which looked like Full City to me. I have seen it recommended on their board that going anywhere near 20 minutes leads to a "baked" flavor in cup. I did not experience this in any preparation with their beans. So my question is this: assuming a decent drum roaster, should one be concerned about taking 20 minutes to reach the desired level of roast?

That's about what it is taking me to roast 10 oz. in my Behmor drum roaster these days - perhaps to a Full City + level (a bit into second crack.)

The beans don't taste baked to me.

Howard

Hi,

Many things come in to play. Not all beans or roasters are equal. And not all batches sizes are equal either. For Ethiopian, fruity beans, it is better to have an aggressive (short) time from the drying to finish phase to make the flavor pop, making the total time short. Longer times may not necessarily bake the flavor but may worsen it. For other beans, it may go the other way around.

If a roaster is overloaded with too many beans, the roast goes very slow and the flavor may suffer relatively speaking. To answer your question, you would need to compare the beans in the same roaster by roasting a shorter time (ie. use half the weight) and longer time , and see which one is better. Every change makes a difference.

Usually, you get flat flavor if the beans are hold for to long in the finish phase, or toasty flavor, if the time to reach 1C is too long.

Cheers

Unventilated and low ventilation drum roasters, like the perforated Burns models, ran from 12 to 20 minutes according to Ukers. Ventilated solid drum roasters manufacturers typically quote 10 to 15 minutes, although Diedrichs models run from 12 to 18. Air and kettle roasters (i.e. full convection heating) quote 8 to 12 minute times.

The trend to shorter roast times was initially driven by purely economic considerations. A roaster that does a batch in five minutes by recirculating heated air saves time and energy. So the same investment in a roasting plant with higher throughput and lower unit costs will have a much better return. The limit was reached with 5 minute roasts, which were so poor tasting that they didn't even work for Folger's. Industrial roasters now use 8 to 12 minute profiles.

Craft roasters using Probat style ventilated drums have settled on 12 to 15 minutes as the optimal roast time. However, since longer roasts and slower drum designs were not abandoned for low quality but for high costs; there is no a priori reason to believe that they are inherently worse tasting.

However, I do have that suspicion. I know too many pro roasters who've souped up their Diedrich's roasters to get to shorter profiles for me not to suspect this. However, I never heard that the longer times made for bad roasts, just not the best ones.

One of the SCAA lectures that I downloaded and listened too (I think the Physics of Roasting one) mentioned that if the Agtron (color) of the roasted unground bean shows little difference from the Agtron of the ground coffee, then it's baked.

Did you get a chance to observe the color differences ground and unground?

I have an insanely powerful roaster and can get to 2nd crack in 5min if I cared to, however extensive logging and cupping has proven to me that ~10min +/- 1min to 426F tastes best. How I get to 426F is another story.

My explanation for the longer roast time is probably more naive. I think the new crop has more moisture, therefore requires longer roast/drying time.

That's not Naive, that's to the point!

It's important to consider where (at what temperature) the roast time is spent. The higher the bean temp, the more critical and sensitive to pace and timing. ....and ET!