Barista Interviews

Stretching and Texturing Milk

Stretching and Texturing Milk

When frothing milk you are doing 2 things to it: stretching - creating froth; texturing/swirling - heating milk.

  1. Start with cold milk in a jug. Never fill it more than halfway because it will expand when heated.
  2. Release some steam form the steam wand, before and after you texture milk. If using a domestic machine, then you must turn on the steam until the liquid water is expelled and only steam emerges.
  3. Lift the milk jug at an angle until the steam wand is 2mm under the milk's surface. Turn on the steam and hold very still while the milk stretches (fig. 1). For a flat white, around 1 second, for a latte, about 2 seconds and around 4 seconds for a cappuccino. Each machine has different pressure, so these times will vary.
  4. Now, lift the jug so that the milk stops stretching (fig. 2). While the steam wand is under the surface, it is heating and swirling the milk. Make sure that the wand does not touch the sides, and that you hold the jug at angle so that it will swirl and heat properly (fig. 3).
  5. When you have a nice swirl happening, hold the jug as still as you can. Use one hand on the handle and the other on the jug (fig. 4).
  6. When the jug is physically too hot to hold, turn off the steam. Keep in mind that women generally have a greater heat tolerance. If you're using a thermometer, stop when it reaches 50 or 55°C, because the temperature reading will continue to rise by around 10 degrees.
  7. Firmly tap the milk jug onto the counter so that you get rid of any big bubbles in your foam.
  8. Pour the milk as soon as you can into your prepared shot. Try to pour evenly and consistently. The first coffee will have more foam than the next, so bear it in mind when you're making milk for more than one. Stretching the milk for 3-4 seconds, for example, will be approximately right for a cappuccino and a flat white if you fill one at a time. You can make 2 lattes from the same milk if you half fill the first, fill the second and then finish the first.

Remember that these times are guides, and you will have to experiment to find what works best. Always stretch your milk first if you're seeking creamy micro foam froth!

Why?

Creating the big bubbles at the beginning will allow you time to swirl the milk in the jug so that the big bubbles hit each other and reduce themselves to smaller bubbles. The more time you have to swirl the milk, the denser the foam. Therefore it's best to start off with fresh, cold milk.

Milk is at its best at approximately 60°C. Its boiling point is at 70-72°C. When milk is heated the sugar content in the milk is also heated up and it caramelises. When it gets hotter than 65°C, the sugar and fat content gets burnt off, making the coffee seem milkier and less sweet.