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Old 04-24-2008, 06:31 PM   #1
jllund62
 
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I read somewhere in this forum, that if you take the original gravity (After the decimal point ,)reading and divide it by 4, you will get an estimate of your final gravity reading.
Is this true, if so how accurate is it?

Example: 1.075- 75 divided 4 = 18.75 so 1.018 is the projected fg

Thanks
Jeffery
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Old 04-24-2008, 06:41 PM   #2
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This assumes an attenuation rate of 75%. If your attenuation rate is 80% then divide by 5, 90% divide by 10.

75% is probably the safest assumption.

Always check for a stable F.G. with a hydrometer in case of bottle bombs. This will also allow you to estimate ABV%.

 
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Old 04-24-2008, 06:42 PM   #3
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Well, if the expected attenuation of the yeast you are using is 75%, then it's a good guideline. It also depends on the recipe- some recipes use more unfermentables than others so they will have a higher FG. But it's not a bad way to make a guestimate of what you could expect from an average fermentation. I usually get 70-80% on almost all of my brews, depending on ingredients and yeast used. I got 69% on one of my last brews, though.
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Old 04-24-2008, 06:42 PM   #4
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Not accurate. depending apon the amount of unfermentables, yeast attenuation, fermentation temps, everything could change your FG number
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Old 04-24-2008, 06:57 PM   #5
jllund62
 
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you lost me !
what is attenuation? I'm a noob
I've heard of it, but not sure what it is.
Thanks
Jeffery
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On Deck: Irish Stout
[B]Brewing: Vienna Lager w/ Brn sugar, Cinnamin ,cloves, and vanilla
Secondary:
Bottled and conditioning: Vienna Lager w/honey ,Cinnamin , cloves, and vanilla
History: Irish Stout W/chocolate was tasty !

 
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Old 04-24-2008, 06:59 PM   #6
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John Palmer's chapter on the subject

I'd recommend reading the whole book...it's great reading.

 
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Old 04-24-2008, 07:09 PM   #7
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Quote:
Originally Posted by jllund62
you lost me !
what is attenuation? I'm a noob
I've heard of it, but not sure what it is.
Thanks
Jeffery
Attenuation rate is the percentage of sugars converted to alcohol. 75% means that 3/4 of the potential alcohol (fermentable sugars) has been converted to the good stuff.

 
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Old 04-24-2008, 07:33 PM   #8
jllund62
 
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Is that what the gauge on the hydrometer is, that says Balling (% sugars)?
I never knew what that meant and I'm still not sure how to use it.
Do you have to take a before and after reading the same way you would w/ the SG?
thanks Jeffery
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On Deck: Irish Stout
[B]Brewing: Vienna Lager w/ Brn sugar, Cinnamin ,cloves, and vanilla
Secondary:
Bottled and conditioning: Vienna Lager w/honey ,Cinnamin , cloves, and vanilla
History: Irish Stout W/chocolate was tasty !

 
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Old 04-25-2008, 12:38 PM   #9
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No, the Balling (and Brix) is just another scale to measure the amount of fermentables. It's used more often by winemakers, I believe.

The attenuation is the amount of sugar transformed to alcohol in a percentage measurement. It is NOT on a scale or a hydrometer. It is usually listed on the yeasts' manufacturer's website, like this:

YEAST STRAIN: 1056 | American Ale™
Very clean, crisp flavor characteristics. Low fruitiness and mild ester production. Slightly citrus like with cool (60-66F, 15-19C) fermentation temperatures. Versatile yeast, which produces many beer styles allowing malt and hop character to dominate the beer profile. Flocculation improves with dark malts in grain bill. Normally requires filtration for bright beers. DE or pad filtration recommended.

Origin:
Flocculation: Medium-Low
Attenuation: 73-77%
Temperature Range: 60-72F, 15-22C
Alcohol Tolerance: 10% ABV
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