Slightly Missed OG, New Target FG?

[JustARogue]

First Post! I started homebrewing this past weekend and have been spending way too much time on these boards reading as much as I can. You guys are awesome.

So for my first batch I choose AHS Evil Brown Ale (Extract). I missed the target OG by a little bit (Targeted: 1.051, Actual: 1.048). I understand that this seems to be not that big of a deal. However, I am wondering what I should expect for my FG now. The recipe targets 1.013 so should I adjust my target to 1.010 or keep it at 1.013?

Thanks again to the homebrew gurus who help us noobs out. The combination of brew advice and psychological counselling (RDWHAHB) makes this place an invaluable resource.

 

[davesrose]

If you want to be absolutely anal about expected FG, here's a good online calculator:

Brew Your Own: The How-To Homebrew Beer Magazine - Brewing Calculator

You'll note that it asks you all kinds of details because expected FG depends on what kind of effeciency you get, as well as what kind of flocculation your yeast strain has. The quick answer is that if you used all the same ingredients and yeast as the recipe, then your FG will be a tad under 1.013.

 

[Rick500]

Multiply 100 minus the average apparent attenuation of your yeast by your actual OG. For instance, if it's 75%, then take 25% of 48 (from 1.048)...which is 12...then use those two digits as the last two for your target FG: 1.012

 

[JustARogue]

Thanks guys. Using Rick's calc the Target FG shifted from 1.013 to 1.012, lol. Thats a finer change than the precision of my hydrometer (.002 marks)