I have never had good luck with sourdough starters. When I lived in "Nearly Canada, North Dakota" my starters never developed any sour taste. I think it was just too cold in our home, even when I placed on our hot water heater. Then again, I only tried them in the winter.
Now I live in "Nearly Mexico, Arizona". Our home is a constant 74 degrees. This time I'm trying a rye and water starter with the 3 step method of 2 oz rye/2 oz spring water for 48 hours, 2 oz rye 4 oz spring water 18 hours, 4 ounces wheat flour, 4 ounces spring water.