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Old 11-03-2012, 06:49 PM   #1
BDN
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I just brewed a Holiday Ale and wan't to test the OG and it was off the chart I couldn't even read it. I use a refractor . Plus how do you get FG with a refractor?

 
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Old 11-03-2012, 08:10 PM   #2
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Was the wort watered down to the batch volume when you read it? What OG were you expecting? If it really is off the charts you could dilute a small sample of the beer with an equal volume of water and double the number that you read.

As for reading final gravity with a refractometer. I recommend that you don't do that. Using a refractometer adds measurement uncertainty because it is dependent on the accuracy of your OG, which in this case you will not be able to read if you already pitched the yeast and would be working from an estimate.

Although I'm biased. IMHO refractometers are fun brewing toys, but I haven't found a real good use for one when making beer.
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Old 11-03-2012, 08:23 PM   #3
BDN
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Thanks Woodlandbrew I have not yet pitched yest but I'll try to dilute a sample to get a reading. The OG needs to be at 1.068-1.072

 
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Old 11-03-2012, 08:33 PM   #4
menerdari
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Diluting a sample will not give you an accurate reading.
Your refract FG reading can be calculated IF you have an accurate OG reading. That said even without an OG reading your refratometer is still usefull in determining that fermentation is done by having consistant readings over several days.

 
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Old 11-03-2012, 08:33 PM   #5
BDN
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Just tested a diluted sample 50/50 came up with 1.054 x2 2.108 that can't be right.

 
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Old 11-03-2012, 08:36 PM   #6
jbeason
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Quote:
Originally Posted by BDN View Post
Just tested a diluted sample 50/50 came up with 1.054 x2 2.108 that can't be right.
It would be 1.108, the gravity of (pure) water is 1.000.

 
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Old 11-03-2012, 08:36 PM   #7
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If you have a hydrometer just use that, more accurate and no math involved
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Old 11-03-2012, 08:49 PM   #8
BDN
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Don't have a Hydrometer will pick one up next time.

 
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Old 11-03-2012, 09:32 PM   #9
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Is it a Brix refractometer? and what range of Brix does it measure?
Refractometers come in many different flavors, and for brewing, you need one that measures from 0 Brix up to about 32 Brix.
32 Brix is approximately 1.133. If your OG is greater than this, you will need a wider Brix range to read it.

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Old 11-03-2012, 09:53 PM   #10
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I just used one from my salt water reef tank.

 
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