How to Tell If Buttermilk Has Gone Bad. Once your buttermilk is chunky, and you can't pour it, or if it has visible mould, it's time to throw it out. Another sign is a strong sour odour
My husband has tried one. I'll wait and see.
That's the best way, try them on a willing guinea pig first. They look good.
If it looked and smelt fine, it should be ok.
I used buttermilk (it was in date) today to make a fruit loaf in the breadmaker but the texture is very close.
I'm sure bread is better made the traditional way in the oven.