Not enough yeast in starter?
When my starter was 1 month old, I could make bread that had great oven spring and a lovely crumb. The taste was mildly sour.
My starter is now about 2.5 months old and it seems to have taken a turn for the worse. The bread I'm getting now has hardly any oven spring and is dense. The taste is more sour than 5 weeks ago, but it's not overly sour.
I fear that my starter doesn't have enough yeast anymore to raise bread sufficiently, but this is just speculation on my part. How do I fix my starter so that it can raise my bread again? I keep my starter at room temperature (around 67-70F). After it has peaked and just barely collapsed (which is about every 12-14 hours) I feed it 1:4:5 (10g S: 40g W : 50g AP Flour).
Thanks for any help.