Too Much Steam Or Milk Boiling
If your Gaggia Brera's steam wand is producing too much steam, or your milk looks like it is boiling, then you may need to make an adjustment to your frothing technique. Boiling milk, or milk that is getting too hot before frothing is completed is an indication that incorrect frothing technique is being used. Review this machine’s “Difficulty Frothing” article for more information.
If you have tried adjusting your technique and the wand still appears to be producing too much steam, then a steam test should be completed.
The Brera also utilizes a special nozzle attachment called a pannarello. The pannarello nozzle needs to be regularly cleaned and properly attached to the machine in order to function. This machine uses a 3-piece style of pannarello instead of the normal 6-piece style. The video below describes how to properly clean and maintain this three piece style of wand:
How to Correct Frothing Problems and Steam Test a Gaggia Brera Espresso Machine
Alternatively, you can try frothing on the machine without the pannarello attachment. The naked wand can also produce a tight microfoam, and is preferred by some users. The major disadvantage of frothing with the naked wand is that it reduces the length of the steam wand by several inches.
If the machine is within the specified steam test range, then the machine is producing the correct amount of steam and an adjustment to frothing technique is necessary. Using a carafe that is chilled in a freezer before frothing is helpful for keeping the milk cooler for longer, allowing for more time to froth before the milk begins to scald.