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.