How do I scale up a recipe?

I've brewed a number of 5 gallon batches of this simple and extremely satisfying Columbus APA recipe, and now I'd like to try a double batch. This is one of my favorite brews (thank you cweston). I've taught at least a couple of BMC drinkers to appreciate homebrew with this ale. Everyone loves the Columbus hop aroma, and most of them quickly learn to like the respectably pronounced (but not hop-head level) hop flavor, the clean taste and medium body of this ale.

The recipe is for 5.25 gallons. How do I scale it up to a double batch of 10.5 gallons? Do I just double all the ingredients? Or is the process more complex than that? I'm especially concerned about getting the hop balance right (bitterness and aroma), since that is really the most salient feature of this ale.

One thing I noticed is that the last time I made this ale, the Columbus hops I had were 14.1% AA, and the ones I have now are 12.2% AA. That's got to affect the bitterness.

Calculate: AAU - Boil time, etc.
I hate math so I use some online calculators that help my math challenged mind.
http://www.tastybrew.com/calculators/recipe.html
http://hbd.org/cgi-bin/recipator/recipator
Plug in the type, AAU, boil time, and wort density (IE volume / SG) and it will give a close idea of the IBU's.
Hope this helps.

From five to ten gallons just multiply by two.

Download the free version of beersmith and plug in your recipe. Use the scale function and voila.

Thanks guys. Beersmith is written for Windows, which I don't have. The online calculator might be useful, but I don't mind doing calculations on paper. That's what I normally do.

I just checked and found that Ray Daniels has IBU calculations in his Designing Great Beers. I believe I'll be able to figure out the hop adjustments.

Recipator is a web-based calculator. But, it really is as simple as doubling everything. The difference in AA% is about 15%, so you would need a little more for the bittering add. If you were using 1 ounce of 14.1% for five gallons, you'd 2.3 ounces of the 12.2% for 10.

Flavor & aroma hops don't need to be adjusted (other than the double).

Throw your recipe up here. Im sure someone could convert it for you.
You silly mac people. JK im thinking about going mac with my next computer.

Thanks david_42, it sounds like it'll be easy.

newkarian, I'm a Linux person, but mac is ok too.

The recipe is cweston's Columbus APA in the recipe section on this site. It's a great APA with a powerful Columbus hop aroma.

According to Beersmith:

18.00 lb Pale Malt (2-Row) US (2.0 SRM) 84.21%
2.00 lb Munich 10L (Briess) (10.0 SRM) 9.36%
1.00 lb Caramel/Crystal Malt - 20L (20.0 SRM) 4.68%
0.25 lb Caramunich Malt (56.0 SRM) 1.17%
0.13 lb Special B Malt (180.0 SRM) 0.58%

0.69 oz Columbus (Tomahawk) [14.50%] (60 min) 21.3 IBU
0.86 oz Columbus (Tomahawk) [14.50%] (20 min) 9.0 IBU
0.86 oz Columbus (Tomahawk) [14.50%] (10 min) 5.3 IBU
0.86 oz Columbus (Tomahawk) [14.50%] (2 min) 4.4 IBU
1.50 oz Columbus (Tomahawk) [14.50%] (Dry hop 14 days) -

OG Est 1.051
FG Est 1.013
SRM Est 8.5
IBUs 40.0

If you're serious about brewing, get BeerSmith. Yes, it's a Windows app. Yes, it runs under Wine. No, there isn't a comparable Linux or Java app (QBrew is mediocre at best).

Thank you Rick500.

Yuri, since you say it works under WIne, then I might go ahead and get it after all. Thanks.

Yep, just install wine, then:

/usr/bin/wineconsole /home/YOU/tmp/beersmith.exe
/usr/bin/wineconsole /home/YOU/tmp/ProMashEval.exe

Just to give them both a shot. It will install an Icon for the app on your desktop and it runs fine on my Fedora 9, so should work with any distribution.