1.
Avraham Sacks asks:
Shalom,
Why is it forbidden to bake all of the loaves if one loaf will certainly be unfit to be eaten on Y.T?
Thank you very much for your help,
Avraham
2.
The Kollel replies:
Dear Avraham,
It doesn't mean that if you bake all the loaves then with each loaf you did another Aveirah. It means that since one loaf is for sure forbidden, you're not allowed to bake all of them because of the one forbidden loaf.
All the best,
Reuven Weiner