Autor gives her a side-eye. He's incredibly precise about his own baking, so to go with a pinch here and an unspecified-measurement-that-fits-in-the-fist there just drives him bonkers. He juices more than enough grapefruit and then measure them out carefully into a bowl--four tablespoons exactly.

"Here," he says, carrying the bowl to her, on ceremony. "Your grapefruit juice."