Steam Milk Like a Pro
From &The Great Coffee Book&
© 1999, Pages 96-98
Timothy J. Castle and Joan Nielsen, Ten Speed Press
The milk steaming process should heat the milk to 150 degrees F, which certainly is warm, but cool enough for most people to begin gingerly sipping their beverage. (A burnt tongue is often the result of oversteaming.) Steaming milk does more than heat the milk-it adds body and changes the texture. When milk is steamed, the foam, or the air that has been added to the milk to give it its additional volume, is incorporated throughout the entire volume of milk, If the steamed milk is used right away, the foam will still be incorporated throughout the entire volume of the drink as well. Once the milk has been steamed, if it is allowed to sit, the foam will rise to the top. The longer the milk is allowed to sit, the "drier" the foam becomes, taking on an airy consistency reminiscent of meringue.
For traditional Italian cappuccinos and macchiatos, the milk is not allowed to separate. In the new American classics, such as lattes and mochas, the milk is required to separate slightly before it is used. Because of this separation, these are considered "layered" drinks, with espresso at the bottom, steamed milk in the middle, and foam at the top.
Regardless of its size, the pitcher should only be filled to one-third of its capacity. Because the milk is heated up to 150'F, and the sides of the pitcher will get very hot, a handle is necessary to hold the pitcher. Stainless-steel pitchers work best. The following are some tips for steaming milk:
* Always "bleed" or "burp" the steam arm, turning it on for a couple of seconds and then off, before and after steaming the milk. This dislodges any milk that is caught in the steam arm from previous steaming.
* Place the tip of the steam arm just below the surface of the milk. Slowly turn on the steam. Place the hand that is not holding the handle of pitcher on the opposite side of the pitcher, in order to steady it.
* As soon as the steam is applied to the milk, watch for the milk to swirl, or form a whirlpool, at the surface. This is the most critical aspect of steaming milk, with the whirlpool serving as a visual clue that you're achieving the proper consistency. (The tip of the steam arm, in relation to its depth in the milk, determines whether a whirlpool forms.) Your ears will also provide clues. If you hear a high-pitched noise, the tip of the steam arm may be too close to the bottom or the sides of the pitcher and no foam will form. If you hear a bubbling sound, then the tip of the steam arm is not far enough below the surface of the milk. The steam is not aerating the milk, and large, unstable bubbles with dry or airy foam will result.
* You'll know the milk is ready when the side of the pitcher becomes too hot to keep your hand on it. In order to preserve the best consistency of the steamed milk and to make sure the inside of the steam arm remains clean, turn the steam down to a gentle whisper as you remove the steam arm from the milk. The steam must be turned down (almost off) before the pitcher of milk is removed or milk will splatter everywhere. (And you'll never make that mistake again!)
* For lattes and mochas, the pitcher of milk should sit undisturbed for about ten to twenty seconds to allow some separation to occur. For cappuccinos and macchiatos, pour the milk immediately.
* For those who really want to get technical: Some kitchen or restaurant supply stores sell thermometers that clip inside milk steaming pitchers.