Honest Gaza - having a thermoblock machine, I'm not sure if you can partially open the steam ... with my old sunbeam, it was either 'on' or 'off'. If you can vary the force of steam coming out, then Remus' advice is good, but I've decided to try and adjust my technique to the force of steam from my machine. Depending on what kind of foam you want, (you can practise this with a jug of water), try to find a position in the jug where the flow of steam into the milk forces the surface to roll over itself. When you achieve this (it can be harder than it sounds), larger foam bubbles are broken up and mixed in with the rest of the milk and you get a more ... consistent consistency (?!?) to your milk. If you get this down-pat, you'll end up with microfoam (no need to italicise that either), which is basically tight foam with bubbles so small you can't even see them. Then again, if you like a mountain of foam on your cappa that resembles Mt. Everest, I can point you in the direction of a cafe that employs a milk-frothing technique reminiscent of masturbation, and quite effective at producing said mountains of bubbly foam. As for me, I've never used a milk thermometer - I've trained my hand, and I'm consistent enough to suit myself. To my thinking, watching (1) the shot of espresso (gotta love the HX's/Dual Thermoblock's ability to simultanously pull shots and steam milk!), (2) the surface movement of the milk, (3) a thermometer, and (4) feeling the side of the jug, whilst having a hand free to turn off the steam and stop the shot is a bit far beyond me.
