Author Topic: Getting high brix comared to hydrometer  (Read 3731 times)

Offline Imperial Stout

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Getting high brix comared to hydrometer
« on: December 15, 2012, 11:26:47 AM »
Just got  new Vee Gee refractometer. Tested brew bottled Dec 10, 2012. Reads 8.4 = 1.035 = 4.6 ABV from 1.070 hydro OG
Had tested FG with 4 hydro's as I picked them up at a yard sale. One was my regular hydro and the other 3 were the yard sale ones. All matched.
Did not have refractometer when brewing. Just tested saved wort. FG from hydro was 1.018 = 6.9 ABV.
This is NOT a 4.6 beer. My wife and I shared a 12 oz beer sample from this batch to taste it. We both could feel it.
Thinking the beer is closer to 7%. Thinking the brix should be 4.4
« Last Edit: December 15, 2012, 11:30:04 AM by Imperial Stout »

Offline tom_hampton

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Re: Getting high brix comared to hydrometer
« Reply #1 on: December 15, 2012, 11:24:07 PM »
Alcohol throws off a refractometer.  You have to compensate for it. Beersmith has a refractometer tool that will correct your readings from fermenting wort.
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Offline grathan

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Re: Getting high brix comared to hydrometer
« Reply #2 on: December 16, 2012, 07:00:24 AM »
Interesting that punching these numbers into the Beersmith refractometer tool shows %7.8 and the hydrometers showed %6.9, though perhaps that is due to not having an original brix measurement or even perhaps the lack of calibration. I wonder if others using this tool find constant discrepancies between using refractometers and hydrometers?




Also interesting it should be noted that alcohol throws off hydrometers as well. They call it apparent attenuation because of this, because the only true measure of alcohol would involve removing the alcohol from the sample. I wonder if beer labels are using apparent or real attenuation for their abv and whether or not there is much difference between the two.

Offline Imperial Stout

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Re: Getting high brix comared to hydrometer
« Reply #3 on: December 17, 2012, 07:46:51 PM »
OK, crisis averted. Called VEE GEE. During the discussion I realized I was measuring FERMENTED wort containing alcohol, as one poster here mentioned. After realizing my error I used an online conversion calculator. A Brix reading of 8.4, when compensated for alcohol,  would be more like 1.011. The actual hydro reading of 1.018 could have been 1.016, making the brix reading .005 low, an acceptable difference. Hopefully the refractometer is more accurate at measuring FG than a hydrometer is.

For those using a VEE GEE refractometer, they come factory zeroed at 68 deg F. No need to zero the unit after you get it. I did and didn't need to to. Vee Gee will re calibrate the refractometer for nothing as I just bought it. Had to pay shipping both ways but that amounted to $12.60. Nothing when you consider you are getting a factory calibrated refractometer.

Offline tom_hampton

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Re: Getting high brix comared to hydrometer
« Reply #4 on: December 20, 2012, 10:08:02 PM »
No need to use an online calculator, beersmith has one built into the refractometer tool. Just select the fermenting wort option and input the necessary data.

I have a vee gee, as well. I verified my calibration when I got it, and I agree they come calibrated. But, they do drift over time. I checked my calibration before every brew day. I find it changes about once a month by 0.2 brix or so.
R.I.P.:Belgian Blonde
On Tap: Apfelwein, Kolsch(v2), Pumpkin Ale, Belgian Specialty 
Aging/Storing: Coffee Porter, Chocolate Porter, Flanders Red, English Barlywine
Fermenting: Maggie's Altbier
Next Up: PtE(1.1), Belgian Dubbel?

Working thru all BCS recipes