Our Valued Sponsor
OpinionsConsumer ReviewsGuides and How TosCoffeeGeek ReviewsResourcesForums
Coffee: Machines and Brewing Methods
Coffee ratios
Coffee Kids
Help folks who help folks in coffee producing nations.
coffeekids.org
 
Not Logged in: Log In to Postlog in
New Topics updated topics   New Posts new posts   Unanswered Posts new unanswered  
Search Discussion Board search   Discussion Board FAQ faq   Signup sign up  
Discussions > Coffee > Machines > Coffee ratios  
view previous topic | view next topic | view all topics
showing page 4 of 7 first page | last page previous page | next page
Author Messages
MWJB
Senior Member


Joined: 1 Jun 2013
Posts: 183
Location: UK
Expertise: I like coffee

Grinder: Rocky, Lido, Porlex, Hario...
Drip: Not enough room to list...
Posted Sun Mar 9, 2014, 3:42pm
Subject: Re: Coffee ratios
 

http://youtu.be/w1FASjSDrRg

Fast forward to 5:55 to see percolators being evaluated at CBI, samples dehydrated, German made Sartorius Selecta balance scale, 1/10mg sensitivity (they did offer a version with 1/100mg but limited to 100g capacity). Sample delivered to the trays via pipette, rather than weighed.
back to top
 View Profile Link to this post
jpender
Senior Member
jpender
Joined: 11 Jul 2011
Posts: 701
Location: California
Expertise: I like coffee

Grinder: OE LIDO
Vac Pot: S/S Moka Pot
Drip: Aeropress
Posted Mon Mar 10, 2014, 6:30pm
Subject: Re: Coffee ratios
 

Hilarious! And dripping with sexism. I guess that's it how it was in 1960.

MWJB Said:

Sample delivered to the trays via pipette, rather than weighed.

Posted March 9, 2014 link

One might think this would greatly impact the accuracy but in fact it doesn't.
back to top
 View Profile Link to this post
randomcupsofcoffee
Senior Member
randomcupsofcoffee
Joined: 11 Mar 2014
Posts: 1
Location: New Jersey
Expertise: I love coffee

Grinder: La Pavoni
Drip: Chemex
Posted Tue Mar 11, 2014, 8:15am
Subject: Re: Coffee ratios
 

I really appreciate the thorough explanation from this discussion.  I just joined the forum....and very happy to have done so!  THIS IS the palce to be to learn more about coffee and how to make it right.
back to top
 View Profile Visit website Link to this post
jpender
Senior Member
jpender
Joined: 11 Jul 2011
Posts: 701
Location: California
Expertise: I like coffee

Grinder: OE LIDO
Vac Pot: S/S Moka Pot
Drip: Aeropress
Posted Fri Apr 18, 2014, 4:46pm
Subject: Re: Coffee ratios
 

andys Said:

Don't know, I could be mis-remembering what Vince said. But my rule is, if you're going to blame someone, it's always best to blame a dead guy, 'cause he won't complain back.  :-P

Posted March 4, 2014 link

I guess I'm stuck with this quote.

It took six weeks but I finally got hold of the Niven & Shaw paper that Lockhart cited as the source for the 18-22% extraction range. And the last line in that paper reads: "A later report will present an account of the development of the experimental brewing device and the results from its operation."

Very disappointing!

I went back and looked again at the publication on calculating extraction that Lockhart authored. Given the numbers he presents it seems most likely that he measured the beverage volume at or near room temperature. For it to be otherwise would imply a larger than expected absorption of water by the grounds. The numbers are consistent with a measurement at perhaps 140F, if the absorption were a little higher than predicted. But at brewing temperature? No way. It really doesn't make sense that the beverage would be just below boiling temperature anyway. That's not how drip coffee brewing works. So it really seems that Lockhart got 20% like he said.

Did Niven make an error with temperature? I don't have the "later report" but I'd be surprised if that were so. These guys weren't dummies.

So I'm left wondering, what the heck the was Vince talking about? He's not a dummy either.
Vince isn't dead but he's kind of silent. Can we blame him instead?
back to top
 View Profile Link to this post
MWJB
Senior Member


Joined: 1 Jun 2013
Posts: 183
Location: UK
Expertise: I like coffee

Grinder: Rocky, Lido, Porlex, Hario...
Drip: Not enough room to list...
Posted Fri Apr 18, 2014, 8:24pm
Subject: Re: Coffee ratios
 

jpender Said:

So I'm left wondering, what the heck the was Vince talking about? He's not a dummy either.
Vince isn't dead but he's kind of silent. Can we blame him instead?

Posted April 18, 2014 link

I'm not sure why you are so keen to find someone else to blame for the itch you can't scratch, nor why Vince would be culpable for your inability to remember, or take notes on what he said? Much of your posting centres around your belief/recollection that he knows the answer to your query, the fact that he is not overtly confirming so here, simply because you ask publicly & indirectly, is a flimsy basis for encouraging doubt? He has an e-mail...

We know the charts assume a fixed absorbtion, which may/may not occur in the real world (VST software allows you to plug in beverage mass & temp, making an assumed absorbtion ratio moot). The CBI, or any other paper chart, has to have fixed absorbtion in order to function at all.

Without knowing more about the "experimental brewer" & it's characteristics, doesn't this introduce a variable we  can't explore? You said earlier that Lockhart got 19.7%, not 20%, whilst that's not a "go/no go" difference in the cup, it is significant in terms of accurate calculation and a far bigger margin than Lockhart's TDS results would suggest.

Where did 140F come from?

Percolators produce a very hot brew, at brewing temperature.

You're already alluding to 2 different possible protocols/measurement methods, but perhaps wrongly assuming (perhaps not...we can't see what you can see) that there was just one used accross the board for the NCA & MRI sensory research, industry product testing at CBI & as a basis for in-house panel experiments/tests at CBI? We could also have 2 different scenarios/situations in which readings were taken? We also know that in some examples no readings were taken, or if they were, there wasn't enough data recorded to identify precise yield, they just relied on "the usual ratio".

We have a lab scenario where samples can be dehydrated at leisure. But how would that work for large scale sensory testing on the public, brewing by the gallon(s) & needing to identify a concentration to correlate to test samples in real-time (hydrometer sounds good for this?)? We don't even know for sure that the %TDS range and %Yield range, identified in the research for the NCA & MRI charts, were interlocking when they were established? That strikes me as only possible when using one brew ratio, if the purpose of the research was to identify a universal brewing ratio, that neatly tied up both aspects, then we're stuck in a chicken/egg loop?

I still think there is an element of "mysteries of ancient technology" (you know, how people propagate myths about the Atlantians having electric lights, the Egyptians had powered flight etc.) that you are attributing to the pre VST methods, whilst they certainly weren't 'mucking about' & had the technology to extrapolate accurate yields, there wasn't perhaps the requirement to pin them down as accurately as we expect today?

Maybe I'm off base there, maybe you have some trump card up your sleeve where Lockhart cites a target of 21.2% for Brazils in a vac pot & 17.5% for Yirgacheffes in a French press? :-)
back to top
 View Profile Link to this post
jpender
Senior Member
jpender
Joined: 11 Jul 2011
Posts: 701
Location: California
Expertise: I like coffee

Grinder: OE LIDO
Vac Pot: S/S Moka Pot
Drip: Aeropress
Posted Fri Apr 18, 2014, 10:12pm
Subject: Re: Coffee ratios
 

Oh good grief. I was joking about Vince.

I looked at the brew water (2 gallons), predicted absorption (32 oz/lb) and beverage volume (1.68 gallons) and figured that there was no reasonable way that the beverage could be at brew temperature without the absorption being at an unlikely level. Do the math yourself if you like.

Percolator? Lockhart used a drip brewer in this case.

I'm just curious about the history.
back to top
 View Profile Link to this post
MWJB
Senior Member


Joined: 1 Jun 2013
Posts: 183
Location: UK
Expertise: I like coffee

Grinder: Rocky, Lido, Porlex, Hario...
Drip: Not enough room to list...
Posted Sat Apr 19, 2014, 4:12am
Subject: Re: Coffee ratios
 

jpender Said:

Oh good grief. I was joking about Vince.

I looked at the brew water (2 gallons), predicted absorption (32 oz/lb) and beverage volume (1.68 gallons) and figured that there was no reasonable way that the beverage could be at brew temperature without the absorption being at an unlikely level. Do the math yourself if you like.

Percolator? Lockhart used a drip brewer in this case.

I'm just curious about the history.

Posted April 18, 2014 link

We're all interested in the history, or what snippets we can find...but to attribute some uniformity accross all the different snippets, which often contradict each other, might be creeping into 'interpretation/revision' rather than acknowledgement?

So Lockhart's drip brew (2gal in, 1.68gal out) hit 1.396%TDS at 19.7%Yield?

Absorbtion quoted in that case isn't that unlikely. You say "predicted absorbtion and beverage volume", was it a calculation or a measurement?

The figures from Lockhart's drip brew don't concur with brew ratio, absorbtion ratio, nor the parameters of the "ideal box" that formed the basis for MRI/CBI brew chart. Lockhart, Niven & Shaw could all be right. You're looking at different brew ratios, probably different brewers, a jigsaw with one gap & 2 different pieces left over, trying to cram them both into the same space?
back to top
 View Profile Link to this post
jpender
Senior Member
jpender
Joined: 11 Jul 2011
Posts: 701
Location: California
Expertise: I like coffee

Grinder: OE LIDO
Vac Pot: S/S Moka Pot
Drip: Aeropress
Posted Mon Apr 21, 2014, 11:35am
Subject: Re: Coffee ratios
 

It's not revisionism if the history isn't known. It's more like archeology. It's as if I found the bones for a three foot long arm and I want to reconstruct what the whole animal looked like. There's no way to be 100% certain without finding the entire fossil but what little I have can be used to build a case based on probability. A three foot arm is most consistent with an animal about our size. Of course it is also consistent with a 40 foot T. rex. But it is more likely that it would belong to a smaller animal than that. With enough constraints like this a reasoned argument, qualified of course, can be constructed.

The numbers given by Lockhart in his extraction example are not consistent with a measurement of the beverage volume while it is hot. What fits his data perfectly is a hot brew water volume measurement combined with a cold beverage volume measurement.

in a similar vein, the idea that a percolator was used by Niven doesn't fit well with what we know. A percolator would require a different extraction calculation and hence a different brew chart. If they'd used a percolator and the existing brew chart Vince wouldn't have been claiming they measured the extraction 1% high, he would have noted that they calculated it nearly 2% too low.

I don't have all the "bones" to solve the puzzle. I have respect for Vince and my inclination is to believe what he said in his talk. But it really looks like Lockhart correctly calculated the extraction in his example.
back to top
 View Profile Link to this post
jpender
Senior Member
jpender
Joined: 11 Jul 2011
Posts: 701
Location: California
Expertise: I like coffee

Grinder: OE LIDO
Vac Pot: S/S Moka Pot
Drip: Aeropress
Posted Mon Apr 21, 2014, 11:40am
Subject: Re: Coffee ratios
 

MWJB Said:

The figures from Lockhart's drip brew don't concur with brew ratio, absorbtion ratio, nor the parameters of the "ideal box" that formed the basis for MRI/CBI brew chart.

Posted April 19, 2014 link

I missed that, but you're right. His own detailed example is inconsistent with the chart in his own paper. The chart expects a cold brew water volume, not hot. It doesn't matter in terms of the extraction he apparently calculated correctly. But it does lead back to the question I was hoping the Niven paper would answer.
back to top
 View Profile Link to this post
MWJB
Senior Member


Joined: 1 Jun 2013
Posts: 183
Location: UK
Expertise: I like coffee

Grinder: Rocky, Lido, Porlex, Hario...
Drip: Not enough room to list...
Posted Mon Apr 21, 2014, 2:35pm
Subject: Re: Coffee ratios
 

jpender Said:

in a similar vein, the idea that a percolator was used by Niven doesn't fit well with what we know. A percolator would require a different extraction calculation and hence a different brew chart. If they'd used a percolator and the existing brew chart Vince wouldn't have been claiming they measured the extraction 1% high, he would have noted that they calculated it nearly 2% too low.

I don't have all the "bones" to solve the puzzle. I have respect for Vince and my inclination is to believe what he said in his talk. But it really looks like Lockhart correctly calculated the extraction in his example.

Posted April 21, 2014 link

Well, I don't know what Niven used, I suggested a percolator simply because you were under the impression a finished brew wouldn't be at "brew temp" (slurry)...it can, or thereabouts (...and because percolators were very common at the time). So assumptions based purely on a perceived temp are shaky.

A percolator can conceivably use the same chart as a drip brewer...at least, as likely as two different drip brewers using the same chart anyway.

If I dug up a 3ft arm and a chicken sized leg, I'd figure on a man who didn't cook his last meal properly, rather than an arm-wrestling chicken! :-)
back to top
 View Profile Link to this post
showing page 4 of 7 first page | last page previous page | next page
view previous topic | view next topic | view all topics
Discussions > Coffee > Machines > Coffee ratios  
New Topics updated topics   New Posts new posts   Unanswered Posts new unanswered     Search Discussion Board search   Discussion Board FAQ faq   Signup sign up  
Not Logged in: Log In to Postlog in
Discussions Quick Jump:
Symbols: New Posts= New Posts since your last visit      No New Posts= No New Posts since last visit     Go to most recent post= Newest post
Forum Rules:
No profanity, illegal acts or personal attacks will be tolerated in these discussion boards.
No commercial posting of any nature will be tolerated; only private sales by private individuals, in the "Buy and Sell" forum.
No SEO style postings will be tolerated. SEO related posts will result in immediate ban from CoffeeGeek.
No cross posting allowed - do not post your topic to more than one forum, nor repost a topic to the same forum.
Who Can Read The Forum? Anyone can read posts in these discussion boards.
Who Can Post New Topics? Any registered CoffeeGeek member can post new topics.
Who Can Post Replies? Any registered CoffeeGeek member can post replies.
Can Photos be posted? Anyone can post photos in their new topics or replies.
Who can change or delete posts? Any CoffeeGeek member can edit their own posts. Only moderators can delete posts.
Probationary Period: If you are a new signup for CoffeeGeek, you cannot promote, endorse, criticise or otherwise post an unsolicited endorsement for any company, product or service in your first five postings.
Cafe Solutions
Commercial sales and service, nationwide installation, equipment leasing options.
www.seattlecoffeegear.com
Home | Opinions | Consumer Reviews | Guides & How Tos | CoffeeGeek Reviews | Resources | Forums | Contact Us
CoffeeGeek.com, CoffeeGeek, and Coffee Geek, along with all associated content & images are copyright ©2000-2014 by Mark Prince, all rights reserved, unless otherwise indicated. Content, code, and images may not be reused without permission. Usage of this website signifies agreement with our Terms and Conditions. (0.34588599205)
Privacy Policy | Copyright Info | Terms and Conditions | CoffeeGeek Advertisers | RSS | Find us on Google+