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Unregistered
02-28-2007, 11:05 AM
How would you convert brix in a solid food product to specific gravity?

Mrs X
02-28-2007, 05:43 PM
Hi, Here's a table. I found it via Wikipedia, and have no idea of the validity of it.

http://www.fermsoft.com/gravbrix.php

°Brix is the weight in grams of sucrose in 100g of solution. The same scale may also apply to solids, but this is a specialised area, and may be easier to find out about from a library book.

Unregistered
06-03-2008, 08:25 AM
Do you have the same table for Brix values abouv 30 ? I need the specific gravity between 60 and 70 Brix.

JohnS
06-04-2008, 09:05 AM
Do you have the same table for Brix values abouv 30 ? I need the specific gravity between 60 and 70 Brix.

Scroll down this web page:
http://www.gfglass.com/refractometer_selection_guides.html
It gives a table from 0-95 Brix.

The "density given is actually specific gravity of solution at 20 °C vs water at 20 °C. Further, I believe the the figures for 5 Brix and 30 Brix are in error. If the data is plotted, it is OBVIOUSLY "unsmooth" at these points.

The Handbook of Chemistry & Physics has a similar table, but one less digit of precision. It gives SG = 1.0196 at 5 Brix, and SG = 1.1290 at 30 Brix. The other data agrees within rounding. (Concentrative Properties of Aqueous Solutions, Table 88). I recommend substitution of these values in the table.

I believe the error is within the original table NBS Circular 440, long out of print, as several sources cite it and have the same error.

Standard quadratic (3 point) interpolation will give excellent results between entries, a cubic will fit the entire range pretty well (standard error 0.00016). Omitting the last two points from the fit improves standard error to 0.0001.

JohnS
06-04-2008, 11:56 AM
The table at the end of this USDA might be more useful:
http://www.ams.usda.gov/AMSv1.0/getfile?dDocName=STELPRD3479342

It dates from 1960 and the values do differ a few parts in the 4th decimal place of SG. No interpolation should be required (or linear would suffice between the close values)

JohnS
07-10-2008, 03:26 PM
Scroll down this web page:
http://www.gfglass.com/refractometer_selection_guides.html
It gives a table from 0-95 Brix.

The "density given is actually specific gravity of solution at 20 °C vs water at 20 °C. Further, I believe the the figures for 5 Brix and 30 Brix are in error. If the data is plotted, it is OBVIOUSLY "unsmooth" at these points.

The link given now returns a "not found" error. However, the table is still cached in Google.
http://64.233.167.104/search?q=cache:qSGjD3nKKToJ:www.gfglass.com/refractometer_selection_guides.html+nbs+circular+4 40+table+109&hl=en&ct=clnk&cd=3&gl=us

By 3rd and 4th order Lagrange interpolation, I have reconstructed the values at 5 and 30 Brix, using surrounding values. It would appear that a typo was made in printing the table and the value for 5 Brix should be 1.01965, not 1.00965. Similarly, value for 30 Brix s/b 1.12898, not 1.11898. If you use ANY table that references Table 109 of NBS Circular 440, make these corrections. The typo is in the original.

If you need absolute density, density of water at 20 °C is 0.99823 kg/L

JohnS
07-11-2008, 04:29 PM
NBS (National Bureau of Standards) is the predecessor to today's NIST. In 1942, it issued a circular 440 with many tables of sugar measurment.

I believe I have sorted out the (minor) difference between the table in posts 4 and 6 and the USDA table in post 5. They are based on different tables from Circular 440. Precision laboratory measurements involve measuring in air (because vacuum is hard on the researchers), and correcting the values to "vacuum" values by detailed air bouyancy calculations. Commercial measurements don't bother and results are "apparent density"

Table 109 is based on absolute or vacuum-adjusted density. There is another table 114 which is the basis of USDA table in post 5, and is still offered on the NIST website today. It is the only remaining portion of Circular 440 still published, as it relates directly to the way commercial producers would measure (apparent density).
The NBS table gives Brix (0-95, by 0.1 increments) over most of the Brix range., apparent specific gravity and specific density. The USDA table gives Brix (0 to 80, by 0.1 increments), specific gravity and degrees Baume; it also gives a temperature correction table

From NIST website:
http://www.boulder.nist.gov/div838/publications.html
NIST Circular 440, Polarimetry, Saccharimetry and the Sugars, (Table 114 only), Brix, apparent density, apparent specific gravity, and grams of sucrose per 100 ml of sugar solutions, 1942.
http://www.boulder.nist.gov/div838/SelectedPubs/Circular%20440%20Table%20114.pdf

For commercial measurements done in air without bouyancy correction, I think only Table 114 or the USDA table in post #5 should be used.

Hopefully this subject is beaten to death. I now know more about Brix than I want to.

Mrs X
07-11-2008, 09:57 PM
Go JohnS! Well done, you deserve a medal. :)

JohnS
07-12-2008, 06:15 AM
Go JohnS! Well done, you deserve a medal. :)

:D I have trouble letting go of things that confuse me.

It wasn't logical that two respectable Federal agencies could give guidance that many "least significant figures" apart without some rational explanation. Eventually, the quest revealed they had been computed on different basis, and the basis or explanation had become detached from the tables through endless "parroting" by others.

The real question is why do people still use Brix when they could use SG or density, but we'll let that one go (or leave it for philosophers). :confused:

Cobalt
12-02-2008, 02:27 PM
For commercial measurements done in air without bouyancy correction, I think only Table 114 or the USDA table in post #5 should be used.
I haven't investigated the NIST table yet, but the USDA table has at least 8 substantial errors. Some are obviously data entry mistakes; some may not be...

Byron B.

Cobalt
12-08-2008, 05:19 PM
Just thought I would share... The errors in the USDA table are going to be corrected; according to very cordial email I've received.

Though the format is not particularly amenable to easy validation, I did some spot checking of the NIST table and didn't find any issues with it.

Byron B.

JohnS
01-09-2010, 04:06 PM
Just thought I would share... The errors in the USDA table are going to be corrected; according to very cordial email I've received.

Though the format is not particularly amenable to easy validation, I did some spot checking of the NIST table and didn't find any issues with it.

Byron B.

Both Table 109 and 114 from NBS (now NIST) use an abrogated definition of the liter, 1.000 028 dm³, rather than the modern (post-1964 definition) of 1 dm³ exactly. The circular containing these tables was published in 1942.

This should not affect the specific gravity columns, but it does affect the density columns. I have not checked the math but it may affect the USDA table too, which seems to be based on table 114.

Unregistered
06-10-2010, 10:41 AM
I've looked at the table 114 data over the range of the ASBC tables/polynomial and found that the differences in Plato (as calculated by the ASBC polynomial) and a 4th order polynomial fit to the table 114 Brix values are accurately described by another 4th order polynomial with coefficients W_coef[0]= {3.18213,-9.1626,8.79724,-2.81615} (in ascending order of power of SG. Thus at 1.0000 SG (apparent) the Plato value is 0.00062 larger than the Brix value. At 1.040 SG the Plato value is 0.00034 larger than the Brix value and at 1.08 SG Plato is 0.00008 larger. The average difference is 0.00034. With the slope of the curves being approximately 0.004 SG/Plato the error going in the other direction i.e. in computing SG from Brix relative to Plato would be about 2.4E-6 SG units at the low end, about 1.4 E-6 in the middle ranges and about 0.3E-6 at the high end of the range. Remember that the Normal-Eichungskommission work was undertaken to correct errors in the Brix tables in the 5th and 6th decimal places. I guess that between the early part of the last century and 1942 the Brix tables were brought into close alignment with the Plato tables.

Bottom line: if you want to convert Brix to Plato plug the apparent SG in question into the polynomial I gave above and add the result to the Brix value. The correction will be in the 4th decimal place.

ajdel@cox.net

Unregistered
06-10-2010, 10:54 AM
How would you convert brix in a solid food product to specific gravity?

The discussion seems to have veered away from the original question but it still deserves and answer and the answer is "You can't." Brix relates to the concentration of sucrose in deionized water - it is the percentage of sucrose per weight. While the meat of a hazelnut certainly has a measurable specific gravity and that specific gravity may well be within the range of the Brix table it would be meaningless to do the interconversion as a hazelnut has lots of other things in it which are not sugar (though it doubtless contains some sugar too).

ajdel

Unregistered
11-11-2011, 05:30 PM
Do you have the same table for Brix values abouv 30 ? I need the specific gravity between 60 and 70 Brix.

I have Cherry Juice Concentrate of 68.0 Brix and need to know the Specific Gravity

Thank you.

Unregistered
11-18-2011, 07:59 AM
Try here:

w w w.davidberryman.co.uk/technical/density/

Ken Carman
03-08-2012, 08:07 AM
:D I have trouble letting go of things that confuse me.

It wasn't logical that two respectable Federal agencies could give guidance that many "least significant figures" apart without some rational explanation. Eventually, the quest revealed they had been computed on different basis, and the basis or explanation had become detached from the tables through endless "parroting" by others.

The real question is why do people still use Brix when they could use SG or density, but we'll let that one go (or leave it for philosophers). :confused:

As to the last comment, for us it's an easy question to answer. We've tried wrapping those bloody things in foam, in cushion material, and always wind up with broken glass... eventually. Last one we bought we never used, wrapped it in cushy foam and next time we brewed I pulled it out of the drawer: broken! Plus I have a real good Brix: easy to read.