I brewed and subsequently bottled 2 batches of beer together, following much the same process for cleaning/sanitizing and brewing throughout. When bottling, I bulk primed both batches with a sugar solution split between them.
Having bottled both batches, one has come out fine with all bottles carbonated, but the other has about half the bottles with no activity.
I suspect the yeast might have died in that latter batch, or an oxygenation problem, but am seeking clarification and suggestions. The flat beer smells and tastes ok, it just hasn't carbonated.