Balancing parameters

roasting & roastery operations

Balancing parameters

Postby James Hoffmann on Tue Jun 06, 2006 12:07 pm

This is kind of an offshoot from the thread on blending by brew temp as started by Matt.

The idea of adapting the rest of technique around a new variable - i.e. How to change your technique to work with 2 degrees cooler....

This is an opportunity for me to publicly try and work around the effects of different parameters in my head:

Brew temp - essentially this is currency for buying solubles from the coffee. The higher you go the more you take. Interesting that Billy said that running hotter allowed him to pull the shots longer (if I understood that right?). This seems kind of odd to me, because a higher temp (in theory) would mean you should complete your extraction of the good variable sooner, meaning a shorter shot. Hence Schomer's high temp, short shot making more sense in my head.

Dose - this is always going to be coupled with grind in my head and I suppose they set up the profile of available solubles. A coarser grind means less surface area is exposed, so in theory the upped dose should balance it, but I suppose what you get is that with a set volume you don't extract the coffee as completely hence getting a different cup. If you move up 2g in the dose how do you best compensate for that? In brew temp?

Shoot me down if I am miles off target, and I know there are a lot more variables - but what are people's thoughts on this?
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Postby Jim Schulman on Thu Aug 10, 2006 6:52 pm

I can't be precise on this; but I can give some anecdotal evidence.

I've home roasted the same basic "house espresso" blend for about four years - Brazil base, aged indo bottom, DP Ethiopians on top with a pinch of WP if I need it. This is my comfort food, palate rester blend, when the SOs and experiments get out of hand.

Upgrading grinders and lowering the inflowing air temperature on my airroaster (PID and insulation on the roast chamber) has at each step allowed me to roast bit lighter and a bit faster while still avoiding the lemonpeel effect. This has upped the sweetness and the clarity of the flavors.

Another upshot is that I've gotten far more picky about my blending coffees

However, I have not really noticed much change with brew temperatures; although this is not the sort of blend that's too picky on this score.

In essence, I think roaster/blenders end up making a series of empirical accomodations to their espresso testing equipment, and improvements in these. If the equipment duplicates that of their cafes and clients, they'll be making these accomodations in the right direction. If there's a wide variety of equipment they are not testing their blends on, they are bound to get a few less than joyous surprises.
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Re: Balancing parameters

Postby xristrettox on Fri Aug 11, 2006 1:11 pm

James Hoffmann wrote:Brew temp - essentially this is currency for buying solubles from the coffee. The higher you go the more you take. Interesting that Billy said that running hotter allowed him to pull the shots longer (if I understood that right?). This seems kind of odd to me, because a higher temp (in theory) would mean you should complete your extraction of the good variable sooner, meaning a shorter shot. Hence Schomer's high temp, short shot making more sense in my head.


What I mean is that when I pull ristretto I have to have a lower temp than when I run normal shots. This, in my experience, works on Hairbender. Same brewtime-ish. I can't say for someone elses coffee.
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Postby Jaime van Schyndel on Sat Aug 12, 2006 7:29 pm

James and Billy,

I would propose that Hairbender is from good ripe green and has a clean acidity(this really should be called citrus). This means a few things:
First off, clean ripe green means clean sweet citrus not defect sourness.
It seems a slightly lower temp for a somewhat light roast will tame some of the clean acidity.
The lower the temps the more you tame the good acidity until it dulls out.
What Billy was doing was compensating by increasing the extraction volume for the higher temp. The other thing would be to lower the dose substantialy to soften the acididty at higher temp. This would have more clarity but lack substantial body.

-On a side note if you really analyze it, essentialy this is the logic for the 13g low dose & low temp shot. Tame the acidity and soften the shot for clarity sacrificing body.

On another side note, I think we all need to rethink the acidity as a catch all phrase.
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