My sourdough suddenly changed
I started a sourdough like over a month ago (started with flour, orange juice, raisins and water, got activity in 4 days, then since then refeshing with equal weight of beead flour and water). It was pretty alive, and did a couple of good breads with it. When i used to refresh it, it gained activity within 45 min, grew in volume, got air bubles trapped and even overflowed sometimes.
Then like a week ago, the activity was slower, and even when active, the bubles are smaller and escaping, rather than lifting the sourdough. Even though am using the same ratio of water to flour in refreshment, the sourdough always feels more liquid... It also smells more acid i guess.
Did not yet try to do a new bread with it, but am afraid of the result.
What happened? Was it contaminated with undesirable bacteria? Is it god or bad? Anyway to fix it if needed?