First a little about milk frothing –
What we’re looking for is a thick, smooth, silky consistency, almost resembling thick paint, for that creamy texture in milk. This is achieved by a steady supply of steam which is easy when you’re using a commercial machine equipped with a large boiler capable of producing large amounts of steam. A combination of air and steam and some practice with swirling the milk around in the pitcher and some tamping from the bottom to burst larger bubbles will get you there.
The challenge and frustration is with the smaller espresso coffee makers for home use. The boilers are small (about 120ml capacity compared to 2 litres upwards for commercial machines) and they need to heat up water for espresso as well as to generate steam.
In comes the Panarello, a kind of cheat device to compensate the lack of steam power.
These Panarellos are designed such that a bit of air is infused along with the steam to assist the frothing process and to create a micro-foam. The Panarello could be a simple pipe sleeve inserted over the steam wand with a micro hole for air intake or the steam wand itself has a small component built in with an array of micro holes serving the same purpose.