I've got a starter going with equal parts organic whole wheat flour and water. For a week, it was fed daily, then went into the fridge in a sealed jar, and fed every 3 days.
When I fed it yesterday, I noticed a sharp odor from it, and the jar 'popped' when I opened it up. I expected some popping, but the smell is different than it was before. Before, it smelled like flour and water, now it smells a bit sharp. I don't know if this is normal or not.
Is this what I should expect?