Just did a quick measure of the Isomac 2 hole tip, they are 1.5mm in diameter, I guess that is way too big lol

The 4-hole tip, with the orifices angled downward between 45 to 30 degrees ought to create a good swirling effect while steaming milk witha vertically oriented wand. The main issue with 4 port tips is balancing steam pressure and steam flow (volume). Having a larger boiler able to generate higher steam pressure will allow more leeway in using multihole steam tips with larger steam orifices (up to a point...that point being when the steam just blasts the milk and doesn't allow you to create that desireable paint-like microfoam)...

In any case, hole size is a critical parameter, along with the number of holes in the tip. They need to be matched with boiler steam capacity and pressure to function optimally for producing good microfoam. The holes can be too big or too small depending on the particular machine. It's hard to make general predictions given the great variability in machines.

I still think the Espro Toroid is worth looking at, especially if you wind up using a one or two hole steam wand helf vertically.

so...I got the 4 hole tip that was from a Bezzera BZ02 (4 x 1mm hole), and I am still struggling to get good microfoam on it.
The steam pattern seems to be more horizontal than downwards (I would guess 30 deg down from the horizontal plane?)
The major challenge at the two stages of steaming are as follow:

1. During stretching, I cannot seem to get the "just right" position for the paper tearing sound. it is either pulling no air (screech) or making huge bubbles......
2. During grooming, I still cannot find a spot to roll or swirl the milk effectively, so the big bubbles just stayed at the top while the bottom is just hot liquid milk.

Any advice?

strikeraj wrote:To my understanding, rather than angle of pitcher vs wand, it is more angle of milk surface vs wand. When the wand is at an angle to the surface of the milk, it will "push" the milk into a vortex. But if I am just tilting the pitcher, the wand is still perpendicular to the liquid itself, and pushing steam to the bottom of the pitcher.

Did I get something wrong in my thought process?

p.s. I did try tilting the pitcher and it was not giving me the nice microfoam as when I tilt the wand...

It makes sense both ways. Yes, if you can move the want to create a jet more horizontal to the surface it easily creates a swirl. With a vertical wand, if you tilt the pitcher forward, the vertical jets will deflect off of the ramped pitcher wall and create horizontal swirl as well. You could maybe focus on trying to get the deflection right.

Thinking about how it's all relative, I wonder if rocking the pitcher side to side while at the same time moving it horizontally around in a small (1 or 1.5 inch) radius centered on the vertical steam wand might do the trick. The 4-hole tip should help create a vortex if the holes are angled downward between 20 and 40 degrees from the horizontal plane.

I actually tried that this morning. Definitely created a better texture than before, But I still have a lot of big bubbles on the surface after milk is at temperature.
The difficultly I found is that I cannot find a position where the surface bubbles can get sucked into the milk without stretching the milk further.
I will see if I can take a video later today