Difference Between Milk for Lattes and Cappuccinos
The difference is all about how much air is introduced. Remember when pouring either latte milk or a cappuccino milk drink; start with an espresso with a good crema layer. Pour milk in the center, breaking the espresso crema layer as little as possible.
Little air is introduced at the start of steaming. When the pitcher starts to get warm the steam tip is then lowered slightly and the milk is rolled using steam power to mix the air throughout the milk producing very fine micro foam.
When steaming, your latte milk should about double in volume; but you can vary this depending on how you like it. When finished steaming, good latte milk resembles wet latex paint in a can.
Latte milk settles less so most all of it mixes completely with the espresso. At the end of the pour a small layer of slightly airier milk will float on top of the crema layer and that’s what can be used for those beautiful latte art designs.
The air is continuously added by keeping the steam tip near the surface of the milk as it expands in the pitcher.
When steaming, your cappuccino milk should about triple in volume; but you can vary this depending on how you like it. When finished steaming, cappuccino milk will be airy and stiffer to the point of holding a momentary peak when poured.
Cappuccino milk quickly settles a bit so less airy milk mixes with espresso and the airier milk foam sits on top of the espresso’s crema layer. For both types, the milk should always be rolling in the pitcher. This helps to break and evenly incorporate the air bubbles.
Heating stops when the milk reaches 140 to 160 degrees but at around 140 you get the sweetest flavor. Beyond 160 degrees milk quickly begins to lose its flavor; destroying any sweetness which is added by steaming. If the milk gets beyond 165 degrees it begins to scald.