The heart of milk foam
Latte art doesn't start with the espresso, but with the milk foam. Texture, temperature and the interaction of milk, coffee and water are crucial throughout the entire process - from the cold start to the finished caffè latte.
Whether the result is a heart, tulip or rosetta depends directly on how the milk foam develops: fine-pored, shiny and stable enough to combine cleanly with the espresso crema.