As I understand it, there are external and internal variables associated with the coffee making process. I'll explain: Internal - Things under your control: Steam pressure, brew temperature, brew pressure, grind size, dosing quantity, etc. External - Things outside your control: Atmospheric conditions, milk variables (batch to batch variability), these things you have to tune your coffee-making process to overcome. Looking back, I made an error in judgement about partially opening the valve. The only thing you can really do is speed up your texturing technique to account for the rapid heating of the milk.
