I have been using a sourdough starter that I grew about six weeks ago from bread flour, water and grapes per a recepie by Nancy Silverton. I've had some great success with the resultant breads. Each evening I feed the starter and each evening it has a healthy bubbly head with a thin layer of hooch and a nice rich aroma. However, ther last two evenings, it seems to be much less active, although still alive, and has developed a strong smell almost like paint. Does anyone know what happened? Is it dying? Is this normal? The only thing I can think of that's changed is it is cooler outside the last couple of days and the barametric pressure has probably changed. Thoughts?