How to deal with mold on pickle? I made a pickle by placing cucumber in a solution of water+vinegar+salt, and left it for 3 weeks. When I opened it, it was covered with white mold all over the solution.


Can I skim the mold from the solution and use the pickle? Does it go inside the solution and cucumbers?
What is the reason for the formation of mold, and how can I avoid it in the future?
Can it be kahm yeast? If yes, how can I tell it from mold?
If your solution grew mold, it would indicate that either the container wasn't sufficiently sterilized before sealing or (probably and) the solution wasn't sufficiently acidic. This can usually be ensured by following a recipe that is known to be good, which should have factors like acidity and water activity accounted for.

As for kahm yeast, it seems that this occurs more frequently on cultured vegetables which would spend some of their time in a less acidic environment (while the culture develops and acidifies). I suppose you could culture it and test it, but when in doubt I'd just toss it.