7.2 Latte Art Faults
When your designs fall short, it will usually be because of technical faults in your milk pitcher manoeuvres that leave you with blurred, faded, or asymmetric images. To help troubleshoot your designs, we have assembled the following descriptors:
If you pour from above the recommended 10-cm height from the surface, your flow of milk can be interrupted. Milk approaches terminal velocity as it falls, and its flow accelerates with its distance from the spout. Therefore, you can have a steady flow rate which works well at a 10-cm, height, but if you raise your spout to 20 cm above the surface, the stream of milk can become broken, causing splashes on the surface and unwanted bubbles in the cup. If you need to increase your flow rate to produce the windmill effect, for example, you must increase the flow rate as you increase your pouring height.
As mentioned in Lesson 4.2, snail trails can mar your latte art design. Even when you pour from a filling height of 10 cm, if you guide the stream of milk through a section of the surface of the milk which is just a brown background, you will see a faint white residue left in the wake of the pour. A common mistake made is when a barista pours orbiting circles around the outside of the cup much too close to the surface (e.g., less than 5 cm). This practice leaves faded stripes around the outside of a pattern, reducing the contrast of a design. The vortexing filling technique will help you reduce this effect during the first half of the pour.
You might notice snail trails forming because of overshoot, when you are employing the cutting technique. Getting more control of the ‘off switch’ (lowering your elbow) will reduce this occurrence.
When you are learning the rosetta, heart, or tulip design, a faded ‘mushroom cloud’ may form at the base of your pattern.