Ask any barista what the key to making a great coffee is and they’ll tell you it’s a good shot and perfectly steamed milk.
What Is Steamed Milk?
Steamed milk is the end result of milk being exposed to high pressured steam from an espresso machine. It is made by introducing steam gradually into milk until the natural fats within it expand to create ‘micro-foam’, a layer of very small milk bubbles. The end result is a smooth, silkily beverage perfect for espresso based drinks. The idea sounds simple enough, but in practise it requires a gentle touch and sound technique.
How To Steam Milk
(1) Fill The Jug With Milk
The first step is filling your jug with milk. This may sound like a obvious step, but it’s actually quite important to get the right amount of milk in your jug, not only to produce the best steamed milk but also for milk conservation. Fill the milk half way up the jug until the surface of the milk hits the lower nudge or ‘v’ of the jug spout.
(2) Milk Stretching
The second step is called ‘stretching’ and is when you turn the steam on and have the nozzle of the steam wand below the surface of the milk to make a hissing sound. This processes creates micro-foam by letting air gently into the milk.
The key is to have the nozzle just a fraction under the surface of the milk in order to create foam while making the milk spin in a whirlpool motion. I find that the milk stretching stage lasts about 5 seconds as you only need to introduce a little bit of air into the milk. Once you create enough foam for your coffee — more for a cappuccino less for a latte — you move onto the third stage.
(3) Milk Spinning/Whirlpool
The third stage is called ‘spinning’ and is when you submerge the steam wand nozzle another fraction below the milk — literally half a centimetre (1/5th of an inch) — and continue to spin the milk in a whirlpool motion. You should hear no hissing sound, other than the occasional leftover bubble being eaten up by the steam wand. This spinning process mixes the micro foam with the milk in order to ‘polish’ the milk. The key to spinning the milk is to tilt the jug a little to get the perfect whirlpool. You’ll need to find the sweet-spot which is a little off-centre and try to keep it there from start to finish.
Keep spinning the milk until the jug becomes too hot to touch or around 60 degrees celsius (140 fahrenheit) then turn off the steam and wipe your steam wand with a wet, clean cloth. However I find for latte art it’s best to have the milk a little cooler around 50 degrees celsius (122 fahrenheit).
(4) Rest and Polish
Once the milk is made give the jug one solid THUMP on the counter to disperse any big bubbles and then leave it to sit whilst you put the espresso shots on. Then, before pouring, swirl the milk around the jug to polish the milk and to make sure the milk and micro-foam is together. The more shiny the milk the better, but don’t be too rough otherwise you’ll make new bubbles. You want the milk to look like wet paint.
When the milk is well-spun, the foam will pour out of the jug first because it sits near the top. You want to pour the milk into the coffee at a steady pace. The key is to pour the milk along side your cup by resting the spout of the jug on the top of your cup.
If you used a big jug you will want to distribute the foam between the different coffees. The general rule is to pour cappuccinos first, hot chocolates second, lattes third and flat whites last. Another handy tip is to ‘split’ your milk by pouring half of your milk into a smaller jug, this lets you have more control of how much foam you add to your milk-based espresso drinks.