If you go by what the company says, "Don't fear the foam" and let the container be in contact with some form of the fluid for 1 minute before use. Its not supposed to affect your beer as long as you pour all the liquid out. That being said I don't like using star san for sanitizing bottles, only kegs and fermenters. I have used star san on bottles(22oz) before with not noticing any taste or priming issue but I prefer cleaning bottles then cooking the bottles in the oven for an hour at 350 then covering the top with foil and letting them cool slowly. Then all I have to do is pull the foil off and fill instead of filling the bottle with star san, pouring out the bottle and having the foam be pushed out and go everywhere..