Scaling the grain bill to 1 bbl and beyond

[jeremiahhansen]

I am trying to scale recipes from 5 gal to 1 bbl.  When scaling recipes to this size (or larger) do you keep the same percentages for each grain?  Or do you have to change the percentages (of the specialty malts for example) when scaling to match the final flavor?

The closest thing I've found on The Brewing Network was a discussion of scaling recipes due to differences in efficiency, but for the same batch size.  In that case it was mentioned to not change the amount of specialty grains, only adjust the base malt.  But that's a different context than scaling from 5 gal to 1 bbl, 10 bbl, etc.

Any helpful tips on this front, or is it as simple as scaling the malts proportionally keeping the same percentages overall?

[brewfun]

The scaling tool does a great job of getting you into the ballpark, if you are using an accurate equipment profile for the larger equipment.

I find that grain percentages are the most accurate way to scale. For hops, I go for the anticipated IBU contribution first, then sort of intuition for late kettle and dry hop additions. Those don't scale very well, since you usually need a lot less per gallon, than on homebrew sized batches, for the same impact.