Select google font in custom CSS

I'd like to select a Google font for my menu. The font is available in the Font Family Theme Options, but selecting it in custom CSS doesn't seem to work. Here's my Custom CSS: #branding ul.menu { font-size: 16px; font-family: "Yanone Kaffeesatz", sans serif; font-weight: bold; } If I select one of the standard fonts (e.g. "Comic Sans MS", cursive, sans-serif;) it works.