Origin and Purpose of Doser - Page 3

#21: Post by **Bluecold** » June 21st, 2010, 5:05 pm

CafSuperCharged wrote:But, Greg (nitpick) and Jim, once upon a time when the stupid Italian engineers who could not know nothing of quality coffee decided they would throw a doser into the barista process they did not have to think about its volume, coffee maturing vs. going stale, and other things but just wild-ass guessed a volume.

Well, the Mazzer Kony has the same size hopper as the Super Jolly. Since the Kony is slower, it is suited to less volume, which means grounds sit longer in the Kony doser than in the SJ doser.

June 21st, 2010, 6:27 pm

I think your reasoning is flawed.
The grinder speed is not the limiting factor in the throughput as long as the doser is large enough to cache grind speed.

Regards
Peter

#23: Post by **Worldman** » June 22nd, 2010, 12:53 pm

Hmmm...is it possible that uber-fresh beans, i.e. 1 hour post roast, can be consumed sooner if ground and allowed to sit for some hours? Will the de-gas process be quickened enough to allow consumption of a good tasting espresso, i.e. one that is not harsh or gassy?

Len <---- can't wait to get my just roasted espresso beans for the week and try it out

#24: Post by **RapidCoffee** » June 22nd, 2010, 1:00 pm

Jim suggests exactly this on p.1 of this thread:

another_jim wrote:If they [roasters] recommend to rest a coffee post roast for several days, grinding it and letting it sit for several hours does the same thing.

#25: Post by **cannonfodder** » June 22nd, 2010, 3:28 pm

Yup, been doing that for a while now. While grinding and letting it sit to degas will eliminate some of the excess gas in the coffee, it still does not mature the blend. Like picking a ripe red tomato verses one picked green then gassed red. You cut down on the excessive crema production but the overall taste is still a bit young. If I am out of beans and all I have is a day or two post roast, I will do this as a cheat or brew regular coffee which is more tolerant of fresh from the roaster coffee.

#26: Post by **Psyd** » June 22nd, 2010, 6:06 pm

cannonfodder wrote:I will do this as a cheat

I agree with Dave. It isn't a solution for bad planning really, just the best available solution when you've run yourself out of beans and your roaster only has what he's roasted today, and last night. It'll work OK, but it's not optimal.

#27: Post by **GC7** » June 27th, 2010, 11:52 am

another_jim wrote:Staleness is an equilibrium state in which all coffees are equally mediocre, no matter how good or bad they were to start out. If you are selling generic coffee, making it completely stale is a great way to ensure consistency and to cut raw material costs. Since most Italian espresso is generic, they stale it as a matter of course.

It takes about a week for ground coffee to stale completely; although since it's an exponential process, a day post grind (espresso fineness) will take care of a lot of the funk (or good aromas, if they are there). The problems is that the coffee sits in the doser far less long.

Just a point for the sake of accuracy. Equilibrium implies a TWO WAY status. Stale coffee is NOT in a state of equilibium as it will never go back towards a fresh state. Stale coffee is an END POINT.

I also can't see where the chemical processes of becoming stale are exponential reactions. That might imply some catalysis which is not the case. If one day will take care of a lot of the funk that only means that those reactions occur faster and a second, third and beyond that set of reactions occurring as coffee ages take place at slower rates.

Back to dosers.

#28: Post by **another_jim** » June 27th, 2010, 9:45 pm

You need to update your avatar or read up past the 18th century. All equilibrium states where entropy is in play are at either the local or global maximum entropy point and irreversible without outside inputs. Second, all isolated chemical reactions are exponential (i.e half-life style decay), since a fixed percentage of the remaining reactants get used up in each time period.

#29: Post by **GC7** » June 27th, 2010, 10:34 pm

Jim - after that answer you need to stick with your day job! You sound like Professor Irwin Corey.

June 28th, 2010, 3:38 am

another_jim wrote:You [GC7] need to update your avatar or read up past the 18th century.

Yes, it is rather assuming to take that one.

another_jim wrote:All equilibrium states where entropy is in play ...

So you are not referring to the maturing/staling of coffee beans through the loss of volatile/gaseous substances any more? (btw, I agree that you can get at an equilibrium that is irreversible.)

another_jim wrote:Second, all isolated chemical reactions are exponential (i.e half-life style decay), since a fixed percentage of the remaining reactants get used up in each time period.

I first read "fixed ... per time" (linear?) but the catch is "fixed percentage ... per time" which would be exponential indeed, implying there would be an asymptote? Seems logical, btw, when concentrations become less all the time.

Enthalpy is no longer what it used to be.

Regards
Peter