They probably kneed it to make sure there isn't a problem that could cost them a lot of dough in compensation.
Thanks so far, for the useful and useless replies.
It's from a piece of Warburtons Toastie. There were two pieces that have had that in it. I've spoken to them and they want me to send it to them asap. I've still no idea what it is.
At yeast if you send it back to them they'll probably give you some vouchers for a few loaves.
My guess is it'll turn out to be something to do with the flour that didn't get milled properly, or more seriously it could be an indicator that something on one of the machines is broken (did they ask for the date/batch of the bread?) and if that's the case it's probably going to require them inspect all the machinery used for that batch.
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