u/No-File-892

So I made a batch of apple pie and it's amazing but I've noticed that the apples have started turning tan. Is this just the alcohol being absorbed into the fruit or should I be worried about it going bad

I'm pretty new to distilling. and as of now I'm just using tap water. I know people say limestone springs make the best liquor but I'm wondering if anybody filters their water and if so what type of setup are you using?