A brief statement on milk temperature.

In short, it should be no more than 65C for optimal taste and texture. The Specialty Coffee Association’s (SCA) protocol states that when milk exceeds this temperature, its flavour profile undergoes significant changes. Overheating milk can lead to the denaturation of proteins and caramelization of lactose (sugars), resulting in a burnt or scorched taste. This alteration masks the milk’s natural sweetness, detracting from the desired balance and complexity of flavours.

In addition to flavour alterations, overheated milk tends to lose its desired velvety consistency, becoming overly thin and lacking in creaminess. Further overheating (closer to boiling point) can often lead to the formation of larger, uneven bubbles in the milk foam (think dry frothy cappuccino as opposed to the smooth latte you ordered), resulting in a less appealing visual presentation and less satisfying drinking experience. However, if you are at a coffee shop and these factors don’t bother you and you want it piping hot, please ask for it extra hot and the server should willingly give you a coffee above 75C.

How to steam perfect latte milk.

Steaming milk involves heating and adding air to the milk to create a creamy, velvety texture. Begin with cold milk in a clean pitcher and purge the steam wand to remove any residual water.Position the steam wand just below the surface of the milk, aiming for a slightly off-centre position to create a whirlpool effect.

Use whichever hand is best for you to hold the pitcher, turn the steam wand on full-power with your free hand and return the free hand to the pitcher, so that you have two hands for stability and so that you can feel the temperature of the pitcher. Once you have completed steaming milk, try not to move the pitcher, as you will disturb the milk/add unwanted air, but use your free hand to turn off the steam wand as quickly as possible (to avoid overheating). 

To keep things simple, here at Kin Coffee, we steam the milk to the same consistency for Latte, Flat White, Cortado and Piccolo, as well as Hot Chocolate, Chai Latte… The list goes on! When steaming, expect the milk to grow or “stretch” in volume by approximately 20% to 30%. Listen for a “paper tearing noise” indicating proper aeration and texturing towards the start of the process.

We find that with this type of milk, keeping the steam wand in more or less the same position works well, due to the increase in volume keeping the steam wand lower in the milk once it has been suitably aerated and then spinning/mixing the bubbles to create microfoam, characterised by a fine, velvety texture and creamy consistency… Your milk should look like wet glossy white paint!

The “C” word and how to gauge temp.

So with Cappuccino, you want to add more air at the start, with total “stretching” of about 40% to 50%. The steam wand should still be positioned just below the surface of the milk, but more air is introduced by gradually lowering the pitcher it as the milk expands.

HOWEVER (this is very important) once you’ve added air at the start and it expands by about 40%, raise the pitcher back up slightly to submerge the steam wand, which will then halt stretching and whip the air around to create a consistently thicker, denser foam suitable for a cappuccino, which you’ll also be able to pour latte art with!

This is also the sort of milk we’d use for a Babyccino (albeit cooled down with cold milk) and for a macchiato.

Regarding temperature, it’s wise to invest in a thermometer so that you can monitor where you’re at, however we use the “too hot to handle” rule… periodically touch the outside of the pitcher with your hand. When the pitcher becomes too hot to handle comfortably, typically around 65°C, it indicates that the milk has reached the desired temperature and should be promptly removed from the steam wand to avoid overheating. This method allows for a tactile approach to achieving the ideal milk temperature for coffee beverages without relying solely on a thermometer. However, everyone’s touch senses vary and subsequently you can use a thermometer to feel how hot 65C feels – For “extra hot” take your hand away and steam for another 5 seconds or so, until you hear a deeper churning sound.

Safety sidenote : 65C is not hot enough to cause burns upon contact with the skin. However, prolonged exposure to temperatures above this range can cause skin irritation or minor burns. It’s essential to exercise caution and avoid prolonged contact with hot surfaces or liquids, especially when steaming milk or working with steam wands, to prevent the risk of injury. Always prioritise safety and use appropriate protective measures when handling hot objects or liquids in the kitchen.

Latte art (separate blog to come)

Latte art works by using the contrast between espresso and steamed milk to create visually appealing designs on the surface of a latte or other espresso-based drinks. As the steamed milk is poured from a high position (allowing it to sink beneath the crema), it creates a canvas for the barista to manipulate. Once the cup is a little fuller, lower the pitcher and continue pouring until you see a small mound of milk foam form on the surface.

By controlling the angle of the pitcher and making subtle movements with their wrist, the barista can guide the flow of milk to form various patterns and designs, such as hearts, rosettas, or tulips. The key is to pour the milk evenly and steadily, allowing the contrasting colours of the espresso and milk to interact and create intricate shapes on the coffee’s surface. With practice and skill, baristas can produce stunning works of art that enhance the coffee-drinking experience for customers… TO BE CONTINUED!