### Author Topic: Improved Refractometer Correction calculator  (Read 9746 times)

#### klickitat jim

• I must live here
• Posts: 8604
##### Re: Improved Refractometer Correction calculator
« Reply #90 on: February 07, 2018, 11:53:31 PM »
Here's what I'm going by
"How to Determine your Refractometer’s Wort Correction Factor

When taking a refractometer measurement of wort, the Brix reading is not necessarily accurate. What is obtained is the Brix WRI (wort refraction index).  Only after dividing the Brix WRI by the wort correction factor is the actual Brix known. It is helpful to know that Brix and Plato are nominally the same to 3 decimal places, so the corrected reading can be treated as Plato (°P).

The correction factor is needed because wort has a different density than sugar water which refractometers are designed for.  The wort correction factor is specific to the instrument."

From a Brewers Friend article explaining their correction factor spreadsheet

By the way, don't think that I did a bunch of work changing my recipes from SG to °P, it's just a click of a button, lol

#### coolman26

• Brewmaster
• Posts: 809
##### Re: Improved Refractometer Correction calculator
« Reply #91 on: February 08, 2018, 12:12:42 AM »
I just read all 10 pages. It is confirmed that this forum is going nowhere.
Excellent read by the way. I always use both hydro and refract. I’ve always calibrated and used. Learn something here every visit.

Sent from my iPhone using Tapatalk
Jeff B

#### Big Monk

• Brewmaster
• Posts: 581
• I am Derek Scott: General Knower Abouter
##### Re: Improved Refractometer Correction calculator
« Reply #92 on: February 08, 2018, 12:21:53 AM »
Here's what I'm going by
"How to Determine your Refractometer’s Wort Correction Factor

When taking a refractometer measurement of wort, the Brix reading is not necessarily accurate. What is obtained is the Brix WRI (wort refraction index).  Only after dividing the Brix WRI by the wort correction factor is the actual Brix known. It is helpful to know that Brix and Plato are nominally the same to 3 decimal places, so the corrected reading can be treated as Plato (°P).

The correction factor is needed because wort has a different density than sugar water which refractometers are designed for.  The wort correction factor is specific to the instrument."

From a Brewers Friend article explaining their correction factor spreadsheet

By the way, don't think that I did a bunch of work changing my recipes from SG to °P, it's just a click of a button, lol

The problem I have is in reading Kai’s conversion chart, you see that an additional factor of 1.04 (across a range of 1.048-1.100 S.G.) needs to be applied to convert °Bx to °P. Unless I’m fouling up concepts here:

1.) Refractometer correction factor takes you from RI to °Bx;

2.) Using Kai’s chart, there exists an additional 1.04 factor across common gravities to concert °Bx to °P.

Maybe I’m wrong? That’s how I’ve always handled it in the LOB spreadsheet, but this conversation has me rethinking myself.

EDIT: On second look, Kai’s Table is labeled, “Refractometer °Bx reading to °P” so it’s liking just conversion factor values, so no extra multiplier needed.
« Last Edit: February 08, 2018, 12:26:29 AM by Big Monk »
“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

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#### klickitat jim

• I must live here
• Posts: 8604
##### Re: Improved Refractometer Correction calculator
« Reply #93 on: February 08, 2018, 12:35:58 AM »
Here's what I'm going by
"How to Determine your Refractometer’s Wort Correction Factor

When taking a refractometer measurement of wort, the Brix reading is not necessarily accurate. What is obtained is the Brix WRI (wort refraction index).  Only after dividing the Brix WRI by the wort correction factor is the actual Brix known. It is helpful to know that Brix and Plato are nominally the same to 3 decimal places, so the corrected reading can be treated as Plato (°P).

The correction factor is needed because wort has a different density than sugar water which refractometers are designed for.  The wort correction factor is specific to the instrument."

From a Brewers Friend article explaining their correction factor spreadsheet

By the way, don't think that I did a bunch of work changing my recipes from SG to °P, it's just a click of a button, lol

The problem I have is in reading Kai’s conversion chart, you see that an additional factor of 1.04 (across a range of 1.048-1.100 S.G.) needs to be applied to convert °Bx to °P. Unless I’m fouling up concepts here:

1.) Refractometer correction factor takes you from RI to °Bx;

2.) Using Kai’s chart, there exists an additional 1.04 factor across common gravities to concert °Bx to °P.

Maybe I’m wrong? That’s how I’ve always handled it in the LOB spreadsheet, but this conversation has me rethinking myself.

EDIT: On second look, Kai’s Table is labeled, “Refractometer °Bx reading to °P” so it’s liking just conversion factor values, so no extra multiplier needed.
So Kai took the leap of faith that we would all need to use Sean's correction factor of 1.04?  How was he not pummeled for That?

Again, it's small taters. Pick a method and go with it, I say. Frankly my eyes aren't good enough to see .1 brix WRI. Best I can do is count the .2 marks

#### dmtaylor

• Official Poobah of No Life.
• Posts: 3476
• Two Rivers, WI
##### Re: Improved Refractometer Correction calculator
« Reply #94 on: February 08, 2018, 12:38:08 AM »
All I know is the 1.04 correction factor does NOT work perfectly for my refractometer.... but a factor of 0.99 does.

Does it really matter?  Now there's a question with no perfect answer!
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.

#### Robert

• Brewmaster General
• Posts: 2443
##### Re: Improved Refractometer Correction calculator
« Reply #95 on: February 08, 2018, 12:45:02 AM »
Does it really matter?  Now there's a question with no perfect answer!

Why this forum isn't going away.
Rob Stein
Akron, Ohio

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

#### klickitat jim

• I must live here
• Posts: 8604
##### Re: Improved Refractometer Correction calculator
« Reply #96 on: February 08, 2018, 12:49:59 AM »
Here's what I'm going by
"How to Determine your Refractometer’s Wort Correction Factor

When taking a refractometer measurement of wort, the Brix reading is not necessarily accurate. What is obtained is the Brix WRI (wort refraction index).  Only after dividing the Brix WRI by the wort correction factor is the actual Brix known. It is helpful to know that Brix and Plato are nominally the same to 3 decimal places, so the corrected reading can be treated as Plato (°P).

The correction factor is needed because wort has a different density than sugar water which refractometers are designed for.  The wort correction factor is specific to the instrument."

From a Brewers Friend article explaining their correction factor spreadsheet

By the way, don't think that I did a bunch of work changing my recipes from SG to °P, it's just a click of a button, lol

The problem I have is in reading Kai’s conversion chart, you see that an additional factor of 1.04 (across a range of 1.048-1.100 S.G.) needs to be applied to convert °Bx to °P. Unless I’m fouling up concepts here:

1.) Refractometer correction factor takes you from RI to °Bx;

2.) Using Kai’s chart, there exists an additional 1.04 factor across common gravities to concert °Bx to °P.

Maybe I’m wrong? That’s how I’ve always handled it in the LOB spreadsheet, but this conversation has me rethinking myself.

EDIT: On second look, Kai’s Table is labeled, “Refractometer °Bx reading to °P” so it’s liking just conversion factor values, so no extra multiplier needed.
Big, I was looking at the page in Kai's blog about the conversion chart. I can't find where he says it's pre-corrected to 1.04

#### klickitat jim

• I must live here
• Posts: 8604
##### Re: Improved Refractometer Correction calculator
« Reply #97 on: February 08, 2018, 12:51:27 AM »
All I know is the 1.04 correction factor does NOT work perfectly for my refractometer.... but a factor of 0.99 does.

Does it really matter?  Now there's a question with no perfect answer!
Right. 1.04 would be a WAG. Your own calculated correction factor would improve your accuracy to SWAG

#### Big Monk

• Brewmaster
• Posts: 581
• I am Derek Scott: General Knower Abouter
##### Re: Improved Refractometer Correction calculator
« Reply #98 on: February 08, 2018, 12:51:41 AM »
We have Refractometer stuff integrated into our sheet so I just like to make sure I keep it as accurate as possible.
“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 us out at www.lowoxygenbrewing.com

#### Big Monk

• Brewmaster
• Posts: 581
• I am Derek Scott: General Knower Abouter
##### Re: Improved Refractometer Correction calculator
« Reply #99 on: February 08, 2018, 12:58:14 AM »
Here's what I'm going by
"How to Determine your Refractometer’s Wort Correction Factor

When taking a refractometer measurement of wort, the Brix reading is not necessarily accurate. What is obtained is the Brix WRI (wort refraction index).  Only after dividing the Brix WRI by the wort correction factor is the actual Brix known. It is helpful to know that Brix and Plato are nominally the same to 3 decimal places, so the corrected reading can be treated as Plato (°P).

The correction factor is needed because wort has a different density than sugar water which refractometers are designed for.  The wort correction factor is specific to the instrument."

From a Brewers Friend article explaining their correction factor spreadsheet

By the way, don't think that I did a bunch of work changing my recipes from SG to °P, it's just a click of a button, lol

The problem I have is in reading Kai’s conversion chart, you see that an additional factor of 1.04 (across a range of 1.048-1.100 S.G.) needs to be applied to convert °Bx to °P. Unless I’m fouling up concepts here:

1.) Refractometer correction factor takes you from RI to °Bx;

2.) Using Kai’s chart, there exists an additional 1.04 factor across common gravities to concert °Bx to °P.

Maybe I’m wrong? That’s how I’ve always handled it in the LOB spreadsheet, but this conversation has me rethinking myself.

EDIT: On second look, Kai’s Table is labeled, “Refractometer °Bx reading to °P” so it’s liking just conversion factor values, so no extra multiplier needed.
Big, I was looking at the page in Kai's blog about the conversion chart. I can't find where he says it's pre-corrected to 1.04

http://braukaiser.com/documents/Kaiser_Brix_Plato_SG_table.pdf

It says “Refractometer °Bx to Wort °P” so my assumption is:

1.) Refractometer °Bx = BrixWRI;
2.) Wort °P = Wort °Bx

You can crunch the numbers and see that for a range of 1.048-1.100 the conversion is ~1.04.

I think this conversation gave me what I need to square my calcs away.
“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 us out at www.lowoxygenbrewing.com

#### klickitat jim

• I must live here
• Posts: 8604
##### Re: Improved Refractometer Correction calculator
« Reply #100 on: February 08, 2018, 01:01:47 AM »
Here's what I'm going by
"How to Determine your Refractometer’s Wort Correction Factor

When taking a refractometer measurement of wort, the Brix reading is not necessarily accurate. What is obtained is the Brix WRI (wort refraction index).  Only after dividing the Brix WRI by the wort correction factor is the actual Brix known. It is helpful to know that Brix and Plato are nominally the same to 3 decimal places, so the corrected reading can be treated as Plato (°P).

The correction factor is needed because wort has a different density than sugar water which refractometers are designed for.  The wort correction factor is specific to the instrument."

From a Brewers Friend article explaining their correction factor spreadsheet

By the way, don't think that I did a bunch of work changing my recipes from SG to °P, it's just a click of a button, lol

The problem I have is in reading Kai’s conversion chart, you see that an additional factor of 1.04 (across a range of 1.048-1.100 S.G.) needs to be applied to convert °Bx to °P. Unless I’m fouling up concepts here:

1.) Refractometer correction factor takes you from RI to °Bx;

2.) Using Kai’s chart, there exists an additional 1.04 factor across common gravities to concert °Bx to °P.

Maybe I’m wrong? That’s how I’ve always handled it in the LOB spreadsheet, but this conversation has me rethinking myself.

EDIT: On second look, Kai’s Table is labeled, “Refractometer °Bx reading to °P” so it’s liking just conversion factor values, so no extra multiplier needed.
Big, I was looking at the page in Kai's blog about the conversion chart. I can't find where he says it's pre-corrected to 1.04

http://braukaiser.com/documents/Kaiser_Brix_Plato_SG_table.pdf

It says “Refractometer °Bx to Wort °P” so my assumption is:

1.) Refractometer °Bx = BrixWRI;
2.) Wort °P = Wort °Bx

You can crunch the numbers and see that for a range of 1.048-1.100 the conversion is ~1.04.

I think this conversation gave me what I need to square my calcs away.
Ok. I thought you were talking about...

#### Robert

• Brewmaster General
• Posts: 2443
##### Re: Improved Refractometer Correction calculator
« Reply #101 on: February 08, 2018, 01:08:58 AM »
Guys, I'm confused now.  I did those disconcerting experiments trying to determine the correction factor for my particular instrument, you recall. I think I'm still leaning toward sticking with my hydrometer, but: am I now to understand that I didn't have to do that? Is 1.04 in fact not a WAG but a reliable universal correction on any instrument calibrated to 0?
Rob Stein
Akron, Ohio

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

#### dmtaylor

• Official Poobah of No Life.
• Posts: 3476
• Two Rivers, WI
##### Re: Improved Refractometer Correction calculator
« Reply #102 on: February 08, 2018, 01:10:50 AM »
Guys, I'm confused now.  I did those disconcerting experiments trying to determine the correction factor for my particular instrument, you recall. I think I'm still leaning toward sticking with my hydrometer, but: am I now to understand that I didn't have to do that? Is 1.04 in fact not a WAG but a reliable universal correction on any instrument calibrated to 0?

I'm a bit confused too, but, I'm pretty sure each individual instrument has its own quirks such that I plan to continue to use 0.99 for my correction factor even if it's "wrong" cuz I'm sure it's right, for me.
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.

#### Big Monk

• Brewmaster
• Posts: 581
• I am Derek Scott: General Knower Abouter
##### Re: Improved Refractometer Correction calculator
« Reply #103 on: February 08, 2018, 01:12:07 AM »
Here's what I'm going by
"How to Determine your Refractometer’s Wort Correction Factor

When taking a refractometer measurement of wort, the Brix reading is not necessarily accurate. What is obtained is the Brix WRI (wort refraction index).  Only after dividing the Brix WRI by the wort correction factor is the actual Brix known. It is helpful to know that Brix and Plato are nominally the same to 3 decimal places, so the corrected reading can be treated as Plato (°P).

The correction factor is needed because wort has a different density than sugar water which refractometers are designed for.  The wort correction factor is specific to the instrument."

From a Brewers Friend article explaining their correction factor spreadsheet

By the way, don't think that I did a bunch of work changing my recipes from SG to °P, it's just a click of a button, lol

The problem I have is in reading Kai’s conversion chart, you see that an additional factor of 1.04 (across a range of 1.048-1.100 S.G.) needs to be applied to convert °Bx to °P. Unless I’m fouling up concepts here:

1.) Refractometer correction factor takes you from RI to °Bx;

2.) Using Kai’s chart, there exists an additional 1.04 factor across common gravities to concert °Bx to °P.

Maybe I’m wrong? That’s how I’ve always handled it in the LOB spreadsheet, but this conversation has me rethinking myself.

EDIT: On second look, Kai’s Table is labeled, “Refractometer °Bx reading to °P” so it’s liking just conversion factor values, so no extra multiplier needed.
Big, I was looking at the page in Kai's blog about the conversion chart. I can't find where he says it's pre-corrected to 1.04

http://braukaiser.com/documents/Kaiser_Brix_Plato_SG_table.pdf

It says “Refractometer °Bx to Wort °P” so my assumption is:

1.) Refractometer °Bx = BrixWRI;
2.) Wort °P = Wort °Bx

You can crunch the numbers and see that for a range of 1.048-1.100 the conversion is ~1.04.

I think this conversation gave me what I need to square my calcs away.
Ok. I thought you were talking about...

Nope that’s his maximum first wort gravity chart, which is our gravity estimation engine in our spreadsheet. We like Kai! 😁
“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 us out at www.lowoxygenbrewing.com

#### Big Monk

• Brewmaster
• Posts: 581
• I am Derek Scott: General Knower Abouter
##### Re: Improved Refractometer Correction calculator
« Reply #104 on: February 08, 2018, 01:14:51 AM »
Guys, I'm confused now.  I did those disconcerting experiments trying to determine the correction factor for my particular instrument, you recall. I think I'm still leaning toward sticking with my hydrometer, but: am I now to understand that I didn't have to do that? Is 1.04 in fact not a WAG but a reliable universal correction on any instrument calibrated to 0?

I'm a bit confused too, but, I'm pretty sure each individual instrument has its own quirks such that I plan to continue to use 0.99 for my correction factor even if it's "wrong" cuz I'm sure it's right, for me.

No. You guys are right. There is a different correction factor for everyone. 1.04 is a generally accepted default value but empirical data says it varies wildly. What I was trying to say, and what is now erroneous, is that I thought an additional factor needed to be applied to convert from Wort °Bx to Wort °P. Not the case.

You guys are on point. Everyone’s correction factor is different. I wouldn’t be surprised if ST just used Kai’s as the default.
“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 us out at www.lowoxygenbrewing.com