The SCAA online resource library is now open to the public. I was checking out a panel discussion with Carl Staub called "How to obtain excellence with drum roasters" 2002. Carl mentions the importance of rapid cooling for the solubility of the sugars. It appears that if it's taking more than 4 mins to cool your roast you will be losing significant amounts of sweetness in the cup. It also effects the formation of espresso. Also interesting is the abilities of sugars passing through a paper filter.
This is the key statement from Carl Staub:

"We all look for sweetness in the cup and something we often ignore is how we cool the coffee after we
roast it. But, it is part of the process. I don't like water quenching, but I am a proponent of trying to cool the
coffee once it comes out of the roaster in four minutes or less. And why do I say that? We've done
experiments using exactly the same strategy cooling the coffee in six minutes, five minutes, and four
minutes. From six minutes to five minutes there is a small improvement in the sweetness of the coffee.
When you go from five minutes to four minutes, the sweetness in the cup doubles and there is a definite
chemical explanation for why that happens. This is due to sugar solubility. The primary sugar in coffee is
sucrose. During the roasting process you fracture the sucrose and you want to caramelize it or polymerize
it in the scientific term. But, you also have to maintain solubility. If it doesn't come out when you put water
into it, it is not going to be a sweet cup. Having the sugar there is one issue, being able to get it out with
hot water is another issue. If you cool it too slowly, the long series chain polymers, sugars, fructose and
glucose will find other constituents to link up with in the coffee and they are not as soluble.
Likewise, during the roasting process if you form molecules that are very large, they may be favorable for
espresso extraction you will get a lot of crema. Having the starches, oils, lipids, and fatty proteins in the
coffee is a very good thing for espresso. But, when you try to apply that same strategy to coffee that is
going through a paper filter, the water doesn't want to go through the filter. The larger molecules get
trapped by the paper filter and don't end up in the cup."
from SCAA Conference Transcript 2002 (Newall, Lee,Diedrich, Staub)

I was just thinking about this. On the other side of the coin, is there any such thing as cooling to roast TOO fast? I go from 430F to room temperature in my roasts in less than a minute, but it seems most professional grade roasters are designed to go to room temperature in 2-4 minutes...

Too fast(at the start) could cause fracturing and divots. Like when as kids we used to heat up crystal marbles and drop them in cold water

What is the "standard" temp that coffee is considered "cooled". 235F? 300F? Room Temp?

That particular article defines cool as room temp. I'm curious what the internal temp lag is.

You could try dumping your beans out of cooling into a container with a TC stuck into the mass or an IR thermometer might work. Unless I hear that something chemically good can happen with the beans being left slightly warm, I cool them right down to room temp.

Ed, thanks for sharing the link. The "How to obtain excellence with drum roasters" was a good find. Have you found any other worthwhile articles? A quick browse was a bit disappointing...

Thanks for the info.

I used to let the Behmor cooling cycle do its thing and always thought that my roasts were lacking something. I don't even remember why, but I started opening the door of the roaster after all 2nd cracks (if any) were completed to accelerate the cooling process. Anecdotally, I thought it improved my roast results. I've never checked to see how cool the beans are after 4 minutes, but I do know the roaster is cooler.

Michael

Regarding cooling using the Behmor, I have always just opened the front door wide open after I hit cool and put a two foot tall 3 speed floor fan on "3" (fastest) and blow for about 4 minutes and it seems to work fine (although I haven't verified how cool the beans get, the air comming out of the unit is substantially cooled so I'm assuming the beans are as well). Only a few chaff flakes are blown out doing this (but I have the old/full size chaff tray which helps). If 2C were really rolling I would wait until the pops subside a bit to avoid encouraging a fire w/ the fan but usually I don't go too far into it. Also, this is done in front of a fireplace so the smoke blows (in general) up the chimney.

Perhaps this is a dumb question, but if the majority of sugars in coffee are sucrose, then why would we care so much about preserving it (if its down...then just put some more sucrose...i.e., table sugar, into the cup?). Just a thought.

Pat