So if I just use 3 gallons in this pale ale recipe instead of 5 ... right?

My instinct tells me I'm way off base on this, but my grasp on recipe science is tenuous at best. Have a recipe for a pale ale. It's a good, solid recipe; a Sierra Nevada clone, pretty much.

For no reason at all I punched it into Beer Calculus at Hopville, switched it from 5 gallons to 3, looked at the numbers, and thought, "Is this now a robust IPA or DIPA?"

The gravity and ABV are in line with that, as are the IBUs, but ... no, that can't be right. I'm clearly missing something here about how recipes scale, so experienced recipe creators, educate me. What am I overlooking?

Cheers!

Can you show what the recipe looked like at 5 gallons and now 3?

Your IBUs/ABV/Gravity should all be the same as the 5 gallon recipe if the scaling converted properly.

I should have been more specific. I looked at my recipe for a five-gallon batch and switched it to three gallons of water, but changed nothing else. No change in the recipe, just dropped the amount of water.

Thats one way to go from a IPA to DIPA or similar Imperial style, but you have to be careful you do not have too much crystal/non-fermentables in the batch. Post the recipe, these guys/gals on here will be sure to give you great advice.

It'd be right in line with this kit from Northern Brewer (PDF warning)

looks like it'd do pretty well as a DIPA at 3gals, aside from the lack of a dry hop. I'd toss in some sugar if you do it tho to make sure it gets dry enough.

I'll keep that in mind, thanks.

If I do this, I do plan a dry hop. Thinking 1.5 oz Cascade, 1 oz Citra.