What is BCB? BCB is a non-consumable formula that has been engineered to closely replicate the texture of milk to finally allow baristas and latte artists of all levels to practice at their heart’s content without the guilt of wasting a single drop of milk. How does it work? Use the dropper to squeeze a 0.25ml shot of BCB into 180ml (6oz) of cold water and forth as if it were milk. Simple as that! How many practice lattes can I make with one bottle? A single 30ml (1oz) bottle can replace up to 20L milk and make up to 100 practice lattes!