Peel and crush the garlic, the entire head. Remove the crusts from the white bread, and place the crustless bread in a mixing bowl. Add the garlic along with the olive oil and vinegar. Let this soften for 1 hour. Beat with an electric mixer until all is smooth. Don't do this with a food processor as it will be too smooth. Add lemon juice, slowly add water while the mixer is running so you will have a thick and fluffy sauce.