Before I did this- I made a solution of sanitizer with Star San to sanitize the pump, bottle, and tubing.
I did this from memory as I made Star San sanitizer about a month ago. But I realized after the fact that I used way too much Star San for the amount of water I had. (It was excessive). Before racking the mead, I emptied the Star San solution the best I could from everything but the siphon, bottle, and piping still had some for sure.
Is my mead likely safe to drink? (There is white foam on the top and I don’t know if it’s from racking or foam from Star San)
With the total lack of detail in your post, I wouldn’t even hazard to guess whether or not it’s safe to drink.
In the scenario you describe, the best solution would have been to rinse everything well, mix some StarSan at the proper dilution and use it to sanitize the bottle and equipment again.
Do you have a way of estimating how much Star San and how much water was used? Star San is pretty safe in terms of just the foam at “regular” strength. Indeed, stories of suck back on a cold crash used to be posted quite regularly here. A small bit will not hurt you, but caution is always encouraged.
Short answer is yes it is safe. None of the ingredients in StarSan are poisonous and then there is the dosage thing on top of that. The main ingredient in StarSan is phosphoric acid, you’ll probably get a higher dose drinking Classic Coke. The other active ingredient is dodecylbenzenesulfonate acid, also non-toxic.
I doubt it will impact flavor either unless it was a completely ape$h1+ dose.