barry wrote:how many shots did you pull at each temp, and was the taste profile consistent across those shots?

I pulled shots over three sessions for each coffee.
In each case I pulled four shots at a set temp (unless I had a shot that either channelled or looked wrong in which case I'd discard and repeat). In most cases I was able to count all four of these shots though, as noted earlier, every once and a while I would get an "off" scoring shot which I would then discard when calculating averages.

I probably should have pulled more shots at each temp but I don't think I could have coped with that amount of coffee. Plus, as it was, I burned through something like 3 pounds of each of the Hairbender and the Artigiano Espresso.

okay... i just wanted to make sure that the differences couldn't be attributed to variation in blend component distribution.

Good point.
I'd not considered that.

I obviously need to repeat the test with an SO espresso.
Yikes. I need another tasting volunteer.

I wonder if bean component distribution would explain some of the random "off" scoring shots that looked fine when extracting... Hmm...

what you might be seeing is an effect of additive taste components (think wave theory). if different tastes come out at different temps, or if the quantity of tastes varies with temp, then perhaps the tastes are additive and subtractive so the resultant flavor peaks vary with temperature, even though all the flavors are there. it sounds like i need to find access to some chromatography equipment.

--barry "just guessing"

barry wrote:okay... i just wanted to make sure that the differences couldn't be attributed to variation in blend component distribution.

How do you control that?...make sure you mix well when blending?

With discrete items like beans does the "ratio" in the blend go south when you grind a small number of beans such as many of us do when we are only making 1 shot?


Sean

barry wrote:okay... i just wanted to make sure that the differences couldn't be attributed to variation in blend component distribution.

I was thinking the same thing. You rock, Barr-Barr.

lennoncs wrote:How do you control that?...make sure you mix well when blending?

This is something that people don't spend nearly enough time thinking about. This is why folks should be wary when you see someone who says that their espresso blend contains 7 or more varieties of arabica, or whatever.

The more types of beans you have, the higher the probability that one or more of the varieties actually won't make it into a particular double-shot, or other such problems. 5 varieties is usually the upper-limit of what's practical.

Tacy... S.O.S. away... but keep in mind, even then... there are still gonna be variations among the coffee beans. Perhaps a little too much science and not enough art, eh?

lennoncs wrote:How do you control that?

you don't. it's a probability issue. any time you have more than one bean type, there will be variation in the relative proportions for any given sample size.

if you blend up 100lbs of Blend A, with 50% X, 25% Y, and 25% Z, then you can only be assured of that proportion at that batch size. if you pull a 10lb aliquot from that 100lb batch, you cannot be assured of the same proportion, no matter how well it has been mixed. pull an 18 gram sample, and, well, you can assume some variation from shot to shot. note that this problem is exacerbated by any increase in the number of components; it is less of an issue for a two-bean blend than for a ten-bean blend.

someplace i have the mathematics behind this... it was a topic of discussion on a.c a number of years ago, and i think david ross and i continued the math into email.

Nick nick nick...
Unless someone has done a poor job with their cupping and sourcing, the odds of you having discernable variance in a group of shots of an SO espresso are really low (statistically relevant, yes, but very low).
This is why we cup all samples in multiple cups and over multiple flights before purchasing.
Now obvioiusly I'm not going to use a coffee where such variance is accepted (yemeni coffees, some ethiopian coffees) but rather a washed central or the like where inconsistency would be grounds for rejecting a lot).

lennoncs wrote:
How do you control that?...make sure you mix well when blending?

1 - don't use more than 5 beans in a blend,
2 - cup and evaluate coffees well to choose only very consistent beans for your blend,
3 - accept some variance (it's unavoidable).

I am a lefty and was wandering if any left-handed person has tried the machine. I am ambidextrous and can use my right hand fairly well. I have had to do some adjusting of hands, etc. when using a new espresso machine. Some friends of mine are strictly leftys and have a hard time steaming on most commercial machines. They want to naturally move in the opposite way as a right-handed person does. I am just curious.

I am looking forward to trying the GS5. Actually, I am ready to order one now.

Milton

Chris,

Is it possible that palate fatigue tainted your results? I don't think I can cup more than 6 espresso shots in a row, and you did something close to what 40 ?

malachi wrote:Theory on the mouthfeel... a combination of the low water debit and the temp stability (increased emulsified oils). Are you running with the auto mode (and thus pre-infusion) or continuous brew?

The distinctness of flavours is, indeed, what I mean by "clarity". It's pretty cool, isn't it? You get to find all these varietal characteristics that are usually lost and blended into one monolithic flavour. Love it.

IMHO:
1. A "low" water debit provides a gradual pressure buildup in the first few seconds.
2. This accomplishes an initial "gradual infusion," which is a type of "preinfusion."
3. "Preinfusion" is a strategy to "set up" the coffee cake in an optimal way for the ensuing high pressure extraction
4. A "low" water debit serves NO other purpose after those first critical seconds
5. "Low" means what I measured from the GS3, 65-70 ml in the first 10 sec after hitting the brew switch

I've been running in continuous brew mode exclusively. I don't even know how to set the auto controls at this point.

Abe Carmeli wrote:Chris,

Is it possible that palate fatigue tainted your results? I don't think I can cup more than 6 espresso shots in a row, and you did something close to what 40 ?

Trust me - I didn't drink all of any of them.

And I went through 1.5 large bottles of San Pelligrino today alone.

AndyS wrote:I've been running in continuous brew mode exclusively. I don't even know how to set the auto controls at this point.

Just PM'ed you instructions.

Milton wrote:I am a lefty and was wandering if any left-handed person has tried the machine. I am ambidextrous and can use my right hand fairly well. I have had to do some adjusting of hands, etc. when using a new espresso machine. Some friends of mine are strictly leftys and have a hard time steaming on most commercial machines. They want to naturally move in the opposite way as a right-handed person does. I am just curious.

At the request of someone on CG, I today tried steaming "cross handed" (holding the pitcher with my right hand and reaching across to use my left hand on the lever). It was new and thus difficult, but I think with practice it would work for me. I think it would be very challenging, however, to steam in this manner while pulling a shot.

looking at your numbers Chris, I have to admit to being a bit skeptical of the certitude attached to your conclusions. The difference between sixes and sevens, or sevens and eights in your personal scoring - given palate fatigue, subtle subjectivities, and all the many small variables (inter-shot portafilter temp variances, blend distribution, barista inconsistencies) - I'm not able to read that chart as necessarily saying too much. I don't doubt that small variations in temperature on a stable machine make notable differences (they certainly do), but I'd be surprised if there was any map you could draw of that narrow band of the state space that would hold true outside of a single session. But I encourage you to try.

Overall, do you feel like the final scoring on those shots accurately reflected your relative experiences of them, or did the differences emerge more from the data? Would these findings still hold true on the 'bender after another days resting of the coffees? Would the noted differences still carry over if you adjusted the dosing regimens?

I do feel that the overall scores reflect my experience of all the shots to be honest.

The scores represent three sessions, not one. And the middle session reversed the temp (decreasing rather than increasing by increments of 0.3F).

It was over two days with one roast, so it did hold up over another day of rest.
And this was consistent across two different coffees.

But please note that the scores are arbitrary and self-referential and do not relate to other coffees or some "Elizabethan Ideal" of "espresso" in any way.

Dosing?
That's another story. I actually have a weird theory that decreasing my dose with the Hairbender would improve the quality at higher temps - but that's a whole different can of worms.

Chris, have you messed around with different temps at same extraction ratios?

espressobsessed wrote:Chris, have you messed around with different temps at same extraction ratios?

Not Chris here, but did you read the entire thread?!
Or maybe I totally misunderstand your question!