Odyssey Espresso (Argos Lever prototype) - Page 61

A haven dedicated to manual espresso machine aficionados.
davidhunternyc
Posts: 190
Joined: 9 years ago

#601: Post by davidhunternyc »

ziptie wrote:From Ross's detail in the YT vid description:
"Those not wanting to mess with pins and retaining clips may purchase our additional piston assembly which ships in the direct configuration and drops in as a simple 1 minute swap."
Whew, this option is heartening. Call me mechanically challenged, a dolt, whatever you want, but I would pull my hair out trying to switch between the spring and manual lever and this ability to easily switch is one of two main selling points for me (the second being a temp stabilized grouphead). When I saw the Youtube video, I said, "no way," I'm not going to do this and even if I could there would be so many steps along the way where I would screw up or damage the machine. Then I read this message from Ross! What a godsend. The Argos is back on the table for me.

versusqc
Posts: 71
Joined: 7 years ago

#602: Post by versusqc »

Ross posted some graph of the temperature using a scace through pulling multiple shots in a row:

This is shot 2-5, shot 1 had a similar 95 -> 80 declining temp. I like the stability between the shots, but isn't this a big drop in temp during the shot? Anyone with a more informed opinion on how this looks?
edit: cut from this graph is a 30s recovery time between each shot

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retireddude
Posts: 233
Joined: 4 years ago

#603: Post by retireddude replying to versusqc »

I saw that this morning too. Very interesting. The last two shots had a significantly lower temp drop, I'm guessing due to the group being hotter.

renatoa
Posts: 769
Joined: 7 years ago

#604: Post by renatoa »

You should be aware that for any machine, the preinfusion phase only is guilty to cut about 10 C degrees, again, for ANY machine.

That because the three times difference between heat capacity of water and coffee (4.2 vs 1.4 J/gram/degree) and the 2-3 times the water quantity absorbed in preinfusion by a typical machine, for example 45-48 ml of water for 18g coffee in basket.
Putting the above in some equations result an average of 10 C degrees drop the equilibrium temperature of a saturated puck.
You simply can't saturate the puck without this temperature drop... it's only after saturation the temperature start increasing again, due to the continuous flow of hot water though the already heated puck.
So far nobody had the crazy idea to preheat the puck to save some degrees (and surely lose flavors), in the quest of ludicrous stability :D

K7
Posts: 416
Joined: 4 years ago

#605: Post by K7 »

versusqc wrote:Ross posted some graph of the temperature using a scace through pulling multiple shots in a row:
image
This is shot 2-5, shot 1 had a similar 95 -> 80 declining temp. I like the stability between the shots, but isn't this a big drop in temp during the shot? Anyone with a more informed opinion on how this looks?
Maybe I'm too picky but I don't consider 2-3C swings "stable". And the temp drop from 95C to 80C during a shot is huge. I'd like to see the 1st shot curve also.

renatoa
Posts: 769
Joined: 7 years ago

#606: Post by renatoa »

Not picky, but unrealistic.
Did you read my post above ?
Sorry if not clear enough, not English native.

LObin
Posts: 1793
Joined: 7 years ago

#607: Post by LObin »

renatoa wrote:You should be aware that for any machine, the preinfusion phase only is guilty to cut about 10 C degrees, again, for ANY machine.

That because the three times difference between heat capacity of water and coffee (4.2 vs 1.4 J/gram/degree) and the 2-3 times the water quantity absorbed in preinfusion by a typical machine, for example 45-48 ml of water for 18g coffee in basket.
Putting the above in some equations result an average of 10 C degrees drop the equilibrium temperature of a saturated puck.
You simply can't saturate the puck without this temperature drop... it's only after saturation the temperature start increasing again, due to the continuous flow of hot water though the already heated puck.
So far nobody had the crazy idea to preheat the puck to save some degrees (and surely lose flavors), in the quest of ludicrous stability :D
That's if you measure the water temperature at the puck or inside actually (water that has been in contact with the coffee bed), correct?

I understand your point about the temperature dropped caused by the contact with the cooler coffee bed. It seems that from a design perspective, the temperature that's worth measuring is the temperature of the water inside the group as it's about to touch the coffee puck, no? What's referred as the brew temperature.

Just like we never hear about the temperature of the coffee pouring inside the cup.

Anyhow, we've seen scace readings of E61's, saturated groups, commercial levers, Robot, etc. Apples to apples the brew temperature drop during a pull with the Argos seems... Wide?

Actually, similar to the brew temperature curve of the Cafelat Robot... Which is not a bad thing but surprising given their design differences.
LMWDP #592

LObin
Posts: 1793
Joined: 7 years ago

#608: Post by LObin »

K7 wrote:Maybe I'm too picky but I don't consider 2-3C swings "stable". And the temp drop from 95C to 80C during a shot is huge. I'd like to see the 1st shot curve also.
I don't know if it explains the temperature curve but in today's Arcps IG story, the brew temperature was set to 94c but the group temperature was (measured?) only 26c...

LMWDP #592

K7
Posts: 416
Joined: 4 years ago

#609: Post by K7 »

renatoa wrote:Not picky, but unrealistic.
Did you read my post above ?
Sorry if not clear enough, not English native.
You are referring to the inevitable temp drop when water first hits the puck, which the plots don't show entirely because apparently he edited them out.
No argument there, but I am talking about something different: peak & avg temp profile shot-to-shot and intra-shot.
I like that they are sharing raw data, good or bad, like this, but data itself is quite disappointing to me. Maybe things will improve.

IMAWriter
Posts: 3472
Joined: 19 years ago

#610: Post by IMAWriter »

renatoa wrote:Not picky, but unrealistic.
Did you read my post above ?
Sorry if not clear enough, not English native.
Plenty clear enough Excellent explanation.