It says on the bottle that's it's basically a double version of Denver Pale Ale. I'd start by looking for DPA clones. I'm not sure why they called it a DIPA; it's really not. It's much closer to a barleywine, imo. Since it says ipa on the bottle, now no one will buy the month's old bottles sitting on the shelves. I agree, though, that it's pretty good.