The skill of drawing flowers in Italian coffee talk about the amount of steam in milking.

I often see this description in some materials: when making milk foam, as soon as the nozzle touches the milk noodles, all the steam valves will be opened. I don't quite agree with this (except for the two-stage steam valve, because there is no way to operate the steam volume, here I refer to the mainstream knob steam valve). In fact, there is no big problem with this view, but as barista beginners, there is no way to control the weight of the opponent, and the valve button is often screwed. Even for coffee lovers, I think it is best not to use this guiding ideology to operate the steam valve.

Back to the subject, let's talk about air pressure. After the air pressure is formed in the boiler, we open the steam valve, no matter how much it is opened, the steam is sprayed out at this pressure. It's just that the volume is a little small, not the pressure. I suggest that you only need to open the valve to the range where you can foam normally, there is no need to open it all.

If you accept this theory, the coffee maker valve in your store will live a long life. If I accept this point of view, I will talk about how to develop this professional habit.

For example, your coffee machine only needs to be twisted three times in the open direction (remember, three times, not three laps) to emit enough steam for foam, so please use this method to operate the steam valve of your coffee machine in the future. Open three times and close three times. Of course, if it takes two or four turns to get enough steam, follow the above method, and so on. In this way, the valve will no longer be closed too tightly or opened to the slippery wire. Congratulations on the longevity of your valve!

Conclusion: as long as the steam pressure is enough, the valve does not need to be opened to the maximum, there is no need to hit the milk foam with the maximum air volume.