" Céu Azul ", a metanfetamina que Walter e Jesse fazem é na verdade um doce de rock azul:
Blue Sky props consist of crystallized sugar and are essentially pieces of blue rock candy manufactured by the candy store "The Candy Lady" of Albuquerque.
Veja algumas informações na página da loja de doces sobre a história:
Albuquerque’s infamous The Candy Lady in Old Town was approached by the Breaking Bad’s prop department to produce an edible show prop for first Season. After some thought Debbie the Owner of the Candy Lady came up with a crushed white rock crystal candy for them. Breaking bad continued to purchase the “Breaking Bad Candy” prop in White for filming the second season. It wasn’t until the candy was featured on The David Letterman show, did Debbie decide to offer it to the public. The rest is history in the making for Walter White’s Blue Sky. (also known as Big Blue, Blue Magic, and Fring’s Blue)
Você pode até comprar um pouco dela se quiser ter um "céu azul" oficial.