Blending beers

Just took a gravity reading of an english Old ale I brewed last weekend and it is way over attenuated for the style. must of mashed low or something? Anyhow, I was thinking of brewing up a batch of brown ale, and make it a little on the sweet side, to blend with the old ale. The Old ale had a starting gravity of 1.080 and finished at 1.013. I was looking to get the brew more within the guidlines.

That should work…I’ve done something similar on a couple of occasions to modify the profile a bit on finished beers where I’ve felt I missed the mark slightly. But, also keep in mind that the guidelines are not rules set in stone.
What you actually taste in your glass is more important.

Other than that, you should definitely age the beer before definitively assessing the results.
After all, historically speaking, it’s not really “old ale” at all until it has 6-12 months of aging (or ideally, longer).

I’m definitely going to age the thing for a couple months, but I believe it will still taste way to dry for an old ale. If I deside to blend the beer I’ll do it just before kegging.