Racked most of my home-made wine night before last and learned a lesson - - - DON'T use 'fresh' tap water to top-off after racking. The Fluoride etc can kill the fermentation. I managed to save mine by leaving the air-locks off overnight to allow the bad stuff to dissipate while I was allowing new yeast to get started in warm, sugar water. After adding the new yeast to the wine, hey all started up again. I was sure worried for awhile that I had ruined about 10 gal of wine. Won't do that again.