My last bout of bread making was experimenting with sourdough again. One of these days I’m just going to give up completely. The texture turns out right, it’s a beautiful looking loaf, but never very sour. I’ve had my starter for about 20 years now, I’ve even brought it 2000 Mi when we moved. It smells pungently sour and Bubbles away. But it never transfers to the bread very well.
My first try at sourdough I was a teen. I had the starter going, my dad came home from work, got under the house to find what animal had crawled in there and died. LOL, it was my starter he smelled.
Maybe this article will help or tell you why yours are not very sour.