Final answer:
When steaming milk, large soapy bubbles indicate an issue with the steaming technique, usually corrected by adjusting the steam wand position and monitoring milk temperature for a fine microfoam.
Step-by-step explanation:
If steaming milk and you are getting big, soapy bubbles, the adjustment needed typically involves the steaming technique. When the aim is to create a fine, uniform microfoam, rather than large bubbles, one should focus on the position of the steam wand in the milk.
Ideally, the wand should be just below the surface at the beginning to incorporate air and then submerged deeper to create a vortex which evenly heats and mixes the milk. If the wand is too high, it will blow large bubbles into the milk, leading to the soapy texture.
Additionally, the temperature should be closely monitored; overheating the milk can also contribute to poor foam quality.