[Eibach]

Hey everyone i just had a question. So i bought a keg from someone that had been untaped untill i got it. Me and my friend put it in ice for a couple hours then taped it. We have had it not on ice for about a week and a half now, and it started to taste sour, so we just emptyed it out.

I had two questions. Is it bad to leave it outside for the time being, even if it is empty?? we used an air tap. btw

and will there be bacteria groth inside the keg?? and if so is there anyway to clean it out???