QLD CoffeeSnobs "Roast-Off"...

[JavaB]

Re: QLD CoffeeSnobs "Roast-Off"...

Having read and thought about that article - the author has pretty good credentials in the area as he is a consultant to the industry......

1. The beans which exhibit this characteristic have uneven water content.... caused by poor drying technique
2. During roasting they develop a mottled exterior (seen that!!!)
3. the parts with high moisture content roast more slowly.....
4. You end up with uneven roast levels within the bean...
5. This can be reduced by a slow ramp to FC and a relatively short period FC to SC (3 minutes)....

Now most of us try to get to FC pretty quickly and extend the time FC to SC as much as we can - as it enhances the flavour. I was very frustrated by the HT in standard form as it had a slow ramp to FC and then a relatively short intercrack gap.... so it is now modified so it does the reverse!!!

Im not sure this variable roast level is a bad thing.... or needs to be eliminated..... To me the modified HT roasts taste far better.......

Some of the best roasts Ive done were post roast blends using the same variety of beans taken to different roast levels. A greater range of characteristics appeared in the espresso.....

So why not have this same range of roast levels in each an every bean? I cant see it causing a problem (other than for the purists)- and quite possibly enhances the flavour in the cup!!!

What do you think????

[Sparky]

Re: QLD CoffeeSnobs "Roast-Off"...

Yep, thats exactly the phenomenon... internal scorching.

I found the shorter roasts were even, so this is controllable by speeding up the time between first and second cracks. I usually run over 5 minutes, but it seems anything over three is fine. As i said earlier, jasons 15 min roast was even and my 17 min roast was even, but my 20 min roast wasnt. I usually hit first crack at the 11-12 min mark to try and keep the roast even.

Cheers,

Mark.

[pie_in_ear]

Re: QLD CoffeeSnobs "Roast-Off"...

After years of looking at this Im not sure I agree 100% with the author. My own experimentation has suggested that it is more to do with airflow than anything else. Like I said on the day, I havent got answers to this one, but Im collecting observations still. This is where it sits so far.......in brief.
When roasting you are using a combination on conduction and convection heat. The proportions of each is determined by starting heat of the drum, roast profile, airflow, and bean characteristics. Ive observed less dense beans in the imex (air roasater) are lighter inside with dark exterior. When roasting a dense bean in the Diedrich with no airflow Ivé noticed the opposite. This leads me to believe that the proportions of conduction v convection heat need to be such, that the outside and inside of the bean heat proportionaly.

To me the auther of the above mentioned article is saying that the uneveness is caused by the uneven density/moisture content of the bean. It may be, but it can be manipulated. Not all coffee is perfect and the fact that all our beans displayed a variation in cross section colour tells us that it is not something we have to accept as a bean fault.