Temperature and texture are essential to the finished quality of a latte, cappuccino, or other milk-based espresso beverages. Steaming pitchers of velvety milk with fine bubbles and the right foam-to-milk balance takes practice, but it's well worth the effort. Follow the steps below for perfectly textured milk every time.
To start, SUBMERGE THE STEAM WAND
Fill a stainless steel pitcher about halfway with cold milk. Holding the handle with your left hand, submerge the tip of the steam wand of your espresso machine just beneath the surface of the milk. Use your other hand to turn the steam on at full strength, then hold the other side of the pitcher for stability and temperature control. You should hear a slight squeal from the submerged steam wand.
Aerate the milk to STRETCH & TEXTURIZE
Carefully lower the pitcher so the tip of the steam wand peaks over the surface of the milk and gasps at the air above. You should hear a gentle frothy hiss. If the noise is too loud and the milk starts to spray, the milksurface is too far away from the tip of the steam wand and the bubbles created will be too large and frothy, rather than fine and silky. Slowly shift the angle between the surface of the milk and the steam wand to create a whirlpool effect.
Try to resist the urge to jiggle or swirl the pitcher as you aerate the milk. Hold the pitcher steady and texturize until the volume of milk has almost doubled and the side of the pitcher starts to warm.
Complete the HEATING PROCESS
Once the texture of the milk appears thick and glossy, lower the steam wand into the milk until it is entirely beneath the surface once more. For lattes, the temperature of the milk at this point should be about 100-120°F; for foamier cappuccinos, it should be about 135-140°F.
Keep the whirlpool going until you can no longer hold your hand against the side of the pitcher for more than one second. The milk should now be about 150-160°F. This is when milk is the sweetest. If you steam the milk for any longer, the taste will deteriorate as the milk scalds. Turn the steam wand off, remove it from the pitcher, and give it a good wipe with a clean cloth.
Finish with THE POUR
Once you've texturized and heated the milk, try not to let it sit for too long, or the milk and foam will separate. Gently tap the bottom of the pitcher on the counter to disperse any larger bubbles. Use a spoon to gently skim any undesirable froth from the surface of the milk. Give it a little swirl before preparing to pour the milk into your cup of espresso.
Very slowly, with the spout of the pitcher close to the espresso in the cup, allow the milk to slowly roll out of the pitcher. Continue the pour in a gentle continuous motion, drawing the pitcher away from the cup. If you're pouring latte art, bring the spout of the pitcher close to the center of the cup again as you near the end of the milk.