Started a 5gal batch of cherry sunday. It now has a sour smell and no change in SG. Did not use a starter. Do I need to scrap this batch and start over or try pitching more yeast.
IF... And a big IF, your temp is right, (60 - 80) I wouldn't worry about a starter....Just rehydrate another packet of yeast and dump it right in there. It should take right off.
If you have the thing in a 45 Degree basement....Set it in the sink with some "bath warm" water over night...I've had to do this when I get in a hurry with Apfelwein and dont't let the juice warm up (I store supplies in a 38 degree basement.) and it's never failed.