Given the importance of temperature stability (and predictability) when making espresso, why is it not more common to pack the grounds in the portafilter basket and detach the PF from the group head only for the time it would take to pop in the basket?

I can only think of one reason and that is the convenience of baskets that are held in the PF . . . it is much easier to knock out the grounds, but 'snapping' in the basket would disturb the tamped grounds.

but but but . . . the PF must cool down quite a bit while away from the machine . . .

Henry

(hoping this is not a dumb question!)

hbuchtel wrote:Given the importance of temperature stability (and predictability) when making espresso, why is it not more common to pack the grounds in the portafilter basket and detach the PF from the group head only for the time it would take to pop in the basket?

(hoping this is not a dumb question!)

Not dumb at all. That very issue has been subject to a heated debate for sometime now. I prefer dosing and tamping directly to the basket for the very same reason. I covered it in detail in the Brewtus Review. Following is an excerpt:

1) It increases thermal stability in my experience. Detaching the portafiler from the group for 30-40 seconds to dose and tamp reduces both the grouphead and the portafilter temperature.
2) Dosing directly into the basket allows the barista to rotate the basket 360 degrees for improved distribution.
3) It is easier to level your tamp when you tamp into a flat basket.
4) The coffee stays at room temperature until you are ready to pull the shot. Dosing and tamping into a hot portafilter starts "cooking" the coffee prematurely.
5) When entertaining a party, it is very efficient to line up all the tamped baskets (I have five) and shoot them back to back.

Abe Carmeli wrote:4) The coffee stays at room temperature until you are ready to pull the shot. Dosing and tamping into a hot portafilter starts "cooking" the coffee prematurely.

no, not really, and especially not if using a room temp basket.

barry wrote:no, not really, and especially not if using a room temp basket.

Come again? What is the coffee temperature then?

sorry to be a bit abrupt today... it's the day after thanksgiving, i work in a mall, and i'm roasting non-stop.


the basket is insulated from the portafilter by an air gap. the majority of puck heating is radiant heat from the showerscreen. the stainless basket is a relatively poor thermal conductor, and the coffee grounds are even worse thermal conductors.

i've done some datalogging tests with probes at various points within the puck and on the portafilter and basket (8 channels is great for this sort of thing). the top millimeter or so of coffee only reaches 100F after about 60-90 seconds (ballpark, i'm going from memory on this one as i don't have time to look it up). coffee deeper in the puck comes up at an even slower rate. the bottom line is there is usually plenty of time to dose, tamp, and initiate the brew cycle w/o causing undue thermal stress on the grounds.

barry wrote:i've done some datalogging tests with probes at various points within the puck and on the portafilter and basket (8 channels is great for this sort of thing). the top millimeter or so of coffee only reaches 100F after about 60-90 seconds (ballpark, i'm going from memory on this one as i don't have time to look it up). coffee deeper in the puck comes up at an even slower rate. the bottom line is there is usually plenty of time to dose, tamp, and initiate the brew cycle w/o causing undue thermal stress on the grounds.

Got you. For a moment I thought that you meant that when grinding directly to the basket, the coffee does not remain at room temperature. What's on the roaster's menu today, and where do you vent all that smoke?

Abe Carmeli wrote: What's on the roaster's menu today, and where do you vent all that smoke?

so far today i've done:

DSB
espresso roast
2 batches of costa rican for flavors
a batch of costa rican for costa rican
french roast
d-colombian
d-sumatra
colombian

i don't know what more i might need; that changes minute by minute.

smoke goes 8 ft vertical, 13 ft horizontal, and 26 ft vertical up along a support girder and out through the mall roof. we're on the lower level of a two level mall, so exhaust location was very limited.

Do you all have any measurements or estimations of how fast the PF cools down?

Assuming about 30 seconds for dosing and tamping (me!) how much heat would be lost?

Henry

yes, i do, but i can't look it up for a few hours.

hbuchtel wrote:Do you all have any measurements or estimations of how fast the PF cools down?

Assuming about 30 seconds for dosing and tamping (me!) how much heat would be lost?

Henry

I made an attempt to answer that question a while back. What the significance of the answer may be, I don't know.