Author Topic: Improved Refractometer Correction calculator  (Read 12647 times)

Offline Petr

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Re: Improved Refractometer Correction calculator
« Reply #225 on: April 24, 2018, 01:48:10 PM »
An optical hand type, although I have a digital one on order (I really do find refractometers handy in the mash, and this should simplify my brewing.)  Again, don't really need it post boil, just curious.

Try that new one once you'll get it. I'm pretty sure you'll get much better results. I suspect that your refractometer is faulty such great deviation is simply not physically possible if the instrument and its use is ok.

Online Robert

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Re: Improved Refractometer Correction calculator
« Reply #226 on: April 24, 2018, 01:57:17 PM »
Thanks.  Sorry to drag this back up.  (The optical does function usefully in the mash, though, but only when I create a specific correction factor for each batch.  I suppose that supports your assessment of its accuracy.)
Rob Stein
Akron, Ohio

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Offline Petr

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Re: Improved Refractometer Correction calculator
« Reply #227 on: April 24, 2018, 02:30:22 PM »
Thanks.  Sorry to drag this back up.  (The optical does function usefully in the mash, though, but only when I create a specific correction factor for each batch.  I suppose that supports your assessment of its accuracy.)

No problem. I guess it does support that. Wort correction factor should be characteristic of the instrument, not each batch.

Online Robert

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Re: Improved Refractometer Correction calculator
« Reply #228 on: April 24, 2018, 02:57:08 PM »
Thanks.  Sorry to drag this back up.  (The optical does function usefully in the mash, though, but only when I create a specific correction factor for each batch.  I suppose that supports your assessment of its accuracy.)

No problem. I guess it does support that. Wort correction factor should be characteristic of the instrument, not each batch.
But it is at least simple to create specific ones.  I just note WRI at each stage of mash and boil, take a saccharometer and refractometer reading on chilled wort, and work backwards to correct the earlier readings.  These could all be compiled to come up with a single,  instrument-specific number, but as I take all these measurements anyway, it's simple and gives me a tool for tracking the progress of the mash, batch to batch, under different conditions. I'll be more interested in coming up with a single conversion factor on the digital instrument, so I'll be able to quickly and easily get an actual density reading on the fly.  Thanks again for your help.
Rob Stein
Akron, Ohio

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Offline dmtaylor

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Re: Improved Refractometer Correction calculator
« Reply #229 on: July 17, 2018, 12:04:42 AM »
The "Old Cubic" and Novotny formulae continue to be pretty much dead-nuts bulleye for me almost every time, only one odd outlier so far out of five batches.  My own refract vs. hydro data thus far:



You can hopefully see a very light thin line diagonally from lower left to upper right -- that is the "goal line".  Goal is to be right on that line.

Bringing back from the dead...

Just a quick note to let you guys know that 3 additional data points since February also fall directly on the diagonal line for the Novotny Linear formula, and the one Terrill calls "Old Cubic".  I'm sold.  I feel very comfortable using my refractometer for FG readings whenever I want, always accurate within 0.001 which I'd say is good enough.
Dave

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Online Robert

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Re: Improved Refractometer Correction calculator
« Reply #230 on: July 17, 2018, 12:32:47 AM »
I'll join the zombies.... Petr was right about my results improving with my digital refractometer.   I've been using it long enough to conclude that its correction factor is effectively nonexistent,  1.00, with any apparent discrepancy with saccharometer readings attributable to the vagaries of eyeballing a thing floating in turbid, bubbly liquid. I am now confidently using mine throughout the process from mash to FG.  I'm using the BF calculator which uses the Novotný cubic I believe, but this and the two Dave mentions all converge pretty closely and all, as Dave says, "close enough."  In fact, I'd go along with "dead nuts."
Rob Stein
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Offline Big Monk

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Re: Improved Refractometer Correction calculator
« Reply #231 on: July 17, 2018, 12:46:44 AM »
I'll join the zombies.... Petr was right about my results improving with my digital refractometer.   I've been using it long enough to conclude that its correction factor is effectively nonexistent,  1.00, with any apparent discrepancy with saccharometer readings attributable to the vagaries of eyeballing a thing floating in turbid, bubbly liquid. I am now confidently using mine throughout the process from mash to FG.  I'm using the BF calculator which uses the Novotný cubic I believe, but this and the two Dave mentions all converge pretty closely and all, as Dave says, "close enough."  In fact, I'd go along with "dead nuts."

I’ve recently received a Speidel Braumeister 20L so I’m back to just using a hydrometer post brewday to take readings.
“We are what we repeatedly do. Excellence, therefore, is not an act, but a habit.” Aristotle
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Online Robert

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Re: Improved Refractometer Correction calculator
« Reply #232 on: July 17, 2018, 01:09:37 AM »
I'll join the zombies.... Petr was right about my results improving with my digital refractometer.   I've been using it long enough to conclude that its correction factor is effectively nonexistent,  1.00, with any apparent discrepancy with saccharometer readings attributable to the vagaries of eyeballing a thing floating in turbid, bubbly liquid. I am now confidently using mine throughout the process from mash to FG.  I'm using the BF calculator which uses the Novotný cubic I believe, but this and the two Dave mentions all converge pretty closely and all, as Dave says, "close enough."  In fact, I'd go along with "dead nuts."

I’ve recently received a Speidel Braumeister 20L so I’m back to just using a hydrometer post brewday to take readings.
Oh, I have the brew length to pull 200mL saccharometer samples all I want.  I actually find the digital refractometer terribly convenient and probably (now I have the system shaken down) more reliable than the combination of saccharometer, eyeball, and a sample with suspended matter and upwelling bubbles.  (Anything that takes me out of the equation is probably an improvement...  ;D )
Rob Stein
Akron, Ohio

I'd rather have questions I can't answer than answers I can't question.

Offline Big Monk

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Re: Improved Refractometer Correction calculator
« Reply #233 on: July 17, 2018, 03:16:51 AM »
I'll join the zombies.... Petr was right about my results improving with my digital refractometer.   I've been using it long enough to conclude that its correction factor is effectively nonexistent,  1.00, with any apparent discrepancy with saccharometer readings attributable to the vagaries of eyeballing a thing floating in turbid, bubbly liquid. I am now confidently using mine throughout the process from mash to FG.  I'm using the BF calculator which uses the Novotný cubic I believe, but this and the two Dave mentions all converge pretty closely and all, as Dave says, "close enough."  In fact, I'd go along with "dead nuts."

I’ve recently received a Speidel Braumeister 20L so I’m back to just using a hydrometer post brewday to take readings.
Oh, I have the brew length to pull 200mL saccharometer samples all I want.  I actually find the digital refractometer terribly convenient and probably (now I have the system shaken down) more reliable than the combination of saccharometer, eyeball, and a sample with suspended matter and upwelling bubbles.  (Anything that takes me out of the equation is probably an improvement...  ;D )

My handheld refractometer is great for brewday measurements.
“We are what we repeatedly do. Excellence, therefore, is not an act, but a habit.” Aristotle
"Messieurs, c’est les microbes qui auront le dernier mot." Louis Pasteur
Check out The Brewing Troubleshooters at https://brewingtroubleshooter.yolasite.com/

Offline WhiteHausBrews

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Re: Improved Refractometer Correction calculator
« Reply #234 on: August 07, 2018, 05:53:04 AM »
Had to created a forum profile just so I could say thank you all for this thread. It has been tremendously informative and after switching from hydro to refract cold turkey a few brews ago it has really hit home that I should probably do a few comparisons at least to get my correction factor dialed in.

Looking forward to finding more rabbit holes to dive down here. Thanks again!

Offline JuanAldo

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Re: Improved Refractometer Correction calculator
« Reply #235 on: January 03, 2019, 07:53:19 PM »
I'll join the zombies.... Petr was right about my results improving with my digital refractometer.   I've been using it long enough to conclude that its correction factor is effectively nonexistent,  1.00, with any apparent discrepancy with saccharometer readings attributable to the vagaries of eyeballing a thing floating in turbid, bubbly liquid. I am now confidently using mine throughout the process from mash to FG.  I'm using the BF calculator which uses the Novotný cubic I believe, but this and the two Dave mentions all converge pretty closely and all, as Dave says, "close enough."  In fact, I'd go along with "dead nuts."

Sorry for waking up a dead thread again, but out of curiosity, which digital refractometer did you end up buying, Robert?

Online Robert

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Re: Improved Refractometer Correction calculator
« Reply #236 on: January 03, 2019, 11:03:12 PM »
I'll join the zombies.... Petr was right about my results improving with my digital refractometer.   I've been using it long enough to conclude that its correction factor is effectively nonexistent,  1.00, with any apparent discrepancy with saccharometer readings attributable to the vagaries of eyeballing a thing floating in turbid, bubbly liquid. I am now confidently using mine throughout the process from mash to FG.  I'm using the BF calculator which uses the Novotný cubic I believe, but this and the two Dave mentions all converge pretty closely and all, as Dave says, "close enough."  In fact, I'd go along with "dead nuts."

Sorry for waking up a dead thread again, but out of curiosity, which digital refractometer did you end up buying, Robert?
Hanna HI96811.  Can't remember if I bought it direct from Hanna, or elsewhere, I think MoreBeer carries this one.  Anyway, it's working great for me.  Update to the last post there, I've made my own spreadsheet using Petr's equation, and am very happily floaty-thing-free.
Rob Stein
Akron, Ohio

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Offline dmtaylor

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Re: Improved Refractometer Correction calculator
« Reply #237 on: January 04, 2019, 04:02:22 AM »
I like small expensive toys.
Dave

The world will become a much more pleasant place to live when each and every one of us realizes that we are all idiots.