[Steve Ruch]

I want to brew 6 gallons of pilsner, but my setup is for 3 gallon batches so I'm thinking brew a 1.096 3 gallon batch and dilute it to 6 gallons at 1.048. My question: If the IBU level in the 3 gallon at 1.096 is 40 would it still be 40 in the 6 gallons at 1.048, or would it be 20?

[rob_f]

It would be 20 IBU.  The color will also be half the SRM of the original.  Not a problem for a pils.

[Steve Ruch]

It would be 20 IBU.  The color will also be half the SRM of the original.  Not a problem for a pils.

That's what I was thinking; now I'm sure.

[Werks21]

use brewsmith or another software capable of figuring IBU's on concentrated boils and your good to go. You end up using more hops due to decreased utilization but the money spent on hops allows you to brew big on smaller equipment and isn't that great of a expense. Im pleased with brewsmith after having tried what was supposed to be the best free software.

[Steve Ruch]

You end up using more hops due to decreased utilization but the money spent on hops allows you to brew big on smaller equipment and isn't that great of a expense. .

Most of the hops will be sterlings from my backyard so cost is irrelevant.

[a10t2]

The color will also be half the SRM of the original.

That wouldn't be the case in any color model I'm familiar with. Though in a beer this light you wouldn't notice the difference.