Too many cooks may spoil the broth, but it only takes one to burn it.

Julia Child
Julia Child (1912-2004) American chef and writer
(Attributed)

Referring to the Women's Suffrage Movement, as quoted by Madeleine Bingham, Something's Burning: The Bad Cook's Guide (1968) [unverified]. Sometimes said to be in the Introduction to her Julia Child's Kitchen, (1975), but not found there.