Racked Fresh Batch of Stout onto about 1 gallon of star san

and I wasn't even drinking, just not thinking. This was a chocolate milk stout and I lost track of what I was doing and before I knew it I had already run about 2.5 gallons of my stout through my cooler and into the carboy only to realize I never emptied the gallon or so of star san out. I guess this will be a neat little experiment. F.

I feel ya, I racked my apfelwein on a quart of S/S...I could have pulled my hair out.I noticed when the apfelwein almost got to the top of keg.
Posted the Nightmare...Here

https://www.homebrewtalk.com/f35/kegging-nightmare-part-1-a-340975/

I'd bet good money that you'll have no problems whatsoever. There are posts on this site and other forums about racking 2.5 gallons of wort onto 2.5 gallons of star-san solution with no ill effects. Slightly more acidic beer maybe, but probably no problem at all.

I just did this same exact thing with a cherry chocolate stout about three hours ago. thankfully I was filling from the bottom of the keg. This cause the beer to somewhat mix at first but then the lighter colored starsan began to rise on top of the racking beer. After finishing racking I just racked the lighter liquid, about a quart, from the top of the keg. I'm hoping this works, and starsan is safe to drink at diluted levels. If this is my last post, however, I was horribly wrong...

You guys are talking diluted Starsan no doubt.

Well I finally tapped my keg of chocolate milk stout. It was not ruined. Flavors a bit muted but certainly enjoyable.