Drives me mad 
I bought a loaf of bread today from the corner shop, dated BB 3 October. just opened it expecting a nice, white, soft loaf and no - I get a loaf of half-stale, weird stuff that smells vaguely bread-like and is full of so many holes it looks more like a sponge than a foodstuff. This seems to happen about 30% of the time I buy bread from the local shops.
I'm guessing they just add extra raising agent to reduce overall ingredient cost and then some bulking stuff to make sure it conforms to the required 800g, but WTH? It's not even a particularly bad brand, it's Kingsmill!