I boiled off to much

So I got a new BK which is much wider than my old one, and my suspicion came true when I got my brew into the fermenter and discovered that I only ended with a little over 4 gallons on a 5 gallon batch.

My OG post boil ended up at 1.058 instead of the 1.050 I was aiming for so I think my efficiency was close..

What should I do: Top off to 5 gallons with distilled water or just leave it and drink fewer gallons of more concentrated beer?!

I'd top off to hit my target OG. Do whatever you like! Might end up with a tastier beer if you leave it au natural...

I have bottles of spring water available when I come up short on volume, but my OG is high. I try to stay true to the recipe as far as OG/FG. But, either way, your gonna be fine.

If it's my own recipe that I'm brewing for the first time, I may just leave it since I didn't know exactly how it was going to turn out anyway. If I have a pretty good idea of what I'm shooting for or if I'm trying to replicate a trusted recipe, I'll adjust to hit my intended gravity. There are various calculators available to give you the correct amount of top-off water for dilution.

What? Water down good beer!!! Leave it alone. If you want watered down beer, go get a Bud! Make adjustments the next time you brew it.

Beersmith's dilution tool says to add .7 gallons to get an OG of 1.050.