Brix conversion
Brix conversion
I just took a refractometer reading of beer that has been fermenting since Friday (the initial vigorous fermentation looks like it has subsided). It came out at about 12.3 which is around 1.050 SG I think.
This is strange because, although I couldnt take an OG (I smashed my hydrometer), it was supposed to be around 1.044 when I pitched the yeast. I may have messed up my volumes a bit because it was a 10 gallon batch - but not too much I dont think.
Any ideas?
Either A) I don't know how to work the refractometer; B) I wildly miscalculated and made something like a 1.060 ale and its only dropped a few points over the weekend - maybe what I thought was vigorous fermentation was just the growth phase; C) I should relax, dont worry etc.
This is strange because, although I couldnt take an OG (I smashed my hydrometer), it was supposed to be around 1.044 when I pitched the yeast. I may have messed up my volumes a bit because it was a 10 gallon batch - but not too much I dont think.
Any ideas?
Either A) I don't know how to work the refractometer; B) I wildly miscalculated and made something like a 1.060 ale and its only dropped a few points over the weekend - maybe what I thought was vigorous fermentation was just the growth phase; C) I should relax, dont worry etc.
Refractometers are designed for sugar solutions. The presence of alcohol in a fermenting beer affects the readings as alcohol is less dense than water but the refractometer doesn't see it in the same way as a hydrometer - consequently it's not a linear relationship. In fact it's probably the most complicated bit of maths I've seen related to beer. I'd use a software program if you have one or ask nicely someone who has...
If you fancy hurting your head here's the formula
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Specific Gravity from original and final Brix
SG = 1.001843 - 0.002318474*OB - 0.000007775*OB*OB - 0.000000034*OB*OB*OB + 0.00574*FB + 0.00003344*FB*FB + 0.000000086*FB*FB*FB
where:
SG = estimated specific gravity of the sample
OB = Original Brix
FB = Final Brix
Hi All – Just received refractometer from Hong Kong and playing with known hydrometer readings using Beersmith Refractometer Tool, would somebody please explain what you have to enter in the boxes for Finished Beer Calc ABV/OG – entered 5.6 Brix for finished Beer do you have to take an FG hydrometer reading also? missing the point.
In very basic terms, as far as I understand it: the refractometer is for measuring the sugar in liquid, so, you can take a reading before fermentation and convert the brix into the SG.
However with finished or fermenting beer, the brix number won't convert to SG because it's a mix of alcohol and sugars. So, beersmith will do the calc, presuming you know the original gravity.
However with finished or fermenting beer, the brix number won't convert to SG because it's a mix of alcohol and sugars. So, beersmith will do the calc, presuming you know the original gravity.
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I never use the "finished beer" option - that's used to work out what the OG was (if you didn't record it) given the FG brix and FG measured using a hydrometer.
I use "unfermented wort gravity" option to measure the gravity of the wort before yeast is pitched....
and then "fermenting wort gravity" to take daily readings as the beer ferments (you need to have recorded the OG for this calc).
I use "unfermented wort gravity" option to measure the gravity of the wort before yeast is pitched....
and then "fermenting wort gravity" to take daily readings as the beer ferments (you need to have recorded the OG for this calc).
Dan!