I found a dark bug, not a worm, in a bag of “bug-free” flour (with an excellent hechsher!). I opened the bag today and it was properly sealed. I didn’t find any holes in the bag.
I already started the dough with 4 cups of flour and the second time I poured the flour into the cup, I noticed the bug.
What should I do with the started dough, and what can I do with the rest of the flour?
If the bag was not very old, and the flour looked overall good, meaning no holes in the flour, no crumby, web like substance in or around the flour. This indicates the bug you found was an exception, as we are dealing with pre checked flour.
The dough you prepared may be used, if possible the rest of the flour should be sifted before use. If more bugs [3 or more total] are found this would prohibit the dough as well.