by David R. on Fri Sep 03, 2010 12:23 am
The Gaggia Twin's second "boiler" is really a thermoblock, as was common in home machines of an earlier era (for both steaming and brewing). The relatively small thermoblocks of home machines cannot transfer heat to the water at an extremely high rate, so the force of the steam will be weaker than on a boiler machine (though I think the newer machines do better than the old Krups and even Rotel). What you gain in return for this is longer duration (the thermoblock should be able to crank out steam far far longer than your Color's boiler could manage) and of course lack of impact on the brew boiler.
While steaming a large pitcher of milk with a fairly weak steam output is possible, it takes lots of practice, and is not ideal. I occasional choose a steam tip for my big machine which intentionally brings the steam power down to such levels, but only when I am steaming a small amount, such as 4-5oz of milk in a small milk pitcher.
I'm not sure what would be best for you in your case. The machine looks to be operating correctly. You might see some improvement if you can replace the steam wand to one without the plastic jet, but to be honest I think what you really need to do is adjust your steam ritual, for example use a smaller pitcher, steam until it is full, then do another pitcher if that is not enough milk.
David R.