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Old 08-31-2013, 04:16 PM   #1
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Default original and final gravity

im not sure if this is the correct question to be asking but what influences gravity and how can it be changed with out changing the ABV of a brew. im messing around with a triple recipe and my OG should be between 1.075 and 1.085 but my actually gravity is 1.095, my final gravity should be between 1.008 and 1.014 but its actually 1.024. my ABV is 9.3% which is exactly where i want it and im getting this by using 2.59KG of pilsner malt in a 6 litre batch

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Old 08-31-2013, 04:23 PM   #2
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Have you checked the hydrometer calibration? Sometimes they are off - they can even change calibration later if the scale inside slides up or down.

Also, if this is extract, it's almost impossible for the OG to be off. If the correct amounts of extract and water are used, it should give you the correct OG. The reading can be off because of incomplete mixing of boiled wort and top-off water.

Have you checked gravity at least two days apart to be sure it has actually reached FG?

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Old 08-31-2013, 04:32 PM   #3
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Original gravity is influence by the amount of sugars extracted from the malt (called efficiency). There are numerous variable which can influence efficiency; mash temperature, type of sparge, equipment used, etc... Typically a brewer "gets used to" his equipment and know what efficiency to expect, then he will be able to adjust the amount of malt used.

Final gravity is also influenced by numerous variables. Some of there variable are type of yeast, fermentability of the wort, etc...

Palmer's book how to brew and the website Howtobrew.com are a great places to learn about brewing.

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Old 08-31-2013, 04:32 PM   #4
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Quote:
Originally Posted by irishrover32 View Post
im not sure if this is the correct question to be asking but what influences gravity and how can it be changed with out changing the ABV of a brew. im messing around with a triple recipe and my OG should be between 1.075 and 1.085 but my actually gravity is 1.095, my final gravity should be between 1.008 and 1.014 but its actually 1.024. my ABV is 9.3% which is exactly where i want it and im getting this by using 2.59KG of pilsner malt in a 6 litre batch
That sounds about right. Looks like your efficiency was about 70%. Apparent Attenuation was about 75%.

Here is a link that describes it:
http://woodlandbrew.blogspot.com/201...re-theory.html

My book, which will be published next month, has some nice tables that make it easier to figure out how to maximize your efficiency.
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Old 08-31-2013, 05:25 PM   #5
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Originally Posted by ncbrewer View Post
Have you checked the hydrometer calibration? Sometimes they are off - they can even change calibration later if the scale inside slides up or down.

Also, if this is extract, it's almost impossible for the OG to be off. If the correct amounts of extract and water are used, it should give you the correct OG. The reading can be off because of incomplete mixing of boiled wort and top-off water.

Have you checked gravity at least two days apart to be sure it has actually reached FG?
Oh no these are just theoretical numbers I got from a software not from a hydrometer reading
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Old 08-31-2013, 05:38 PM   #6
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Oh.

In that case changing the amount of malt changes the OG.

The attenuation of the strain of yeast will affect the FG.

Since you are talking about a tripel; there is typical a sugar (cane, sometimes candied) addition to Belgian beers. This sugar addition will increase the OG and since it is highly fermentable allows for a lower FG.

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Old 08-31-2013, 06:03 PM   #7
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For further understanding of the how fermentable wort is, research short and long chain carbohydrates.

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Old 08-31-2013, 07:26 PM   #8
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Originally Posted by irishrover32 View Post
Oh no these are just theoretical numbers I got from a software not from a hydrometer reading
I'm really lost now. If the gravities are just theoretical, what do you mean by "actual gravity"?

Also, was this an all-grain or an extract beer? (Some of the other responses talked about mash temperature or efficiency.)
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Old 08-31-2013, 08:58 PM   #9
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I'm really lost now. If the gravities are just theoretical, what do you mean by "actual gravity"?

Also, was this an all-grain or an extract beer? (Some of the other responses talked about mash temperature or efficiency.)
ok - I read over your post again. Looks like I misunderstood it originally - my bad. Since you're working all this on software, my comments won't help. I'll read more carefully next time.
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