I have an automatic milk frother similar to this one.

milk frother

The issue I'm having is that the milk froth that is produces is completely inconsistent.

I'm looking for microfoam consistency that you normally get with a flat white, like this.


But often I get really large bubbles that you get with a cappuccino, like this.

large bubbles

There doesn't seem to be any pattern between getting the microfoam vs. large bubbles:

  • The milk fat content (and usually brand) is consistent.
  • The milk temperature is the same (out of the same fridge).
  • The milk quantity that I put in the frother is the same (I pour it up to a specific line each time).
  • The frothing duration is the same (as far as I know) - it's all automated, but I don't stop it prematurely.

Any idea why I'm getting such unreliable results? I'd like to know how to get the microfoam each time I make a coffee, but it seems to be luck of the draw each time.

  • Hi, welcome to Coffee SE! Can you please add a link to the specific frother you use? This might allow us to provide more specific ideas.
    – R Mac
    Jun 21, 2021 at 17:37
  • @rmac - it is this model: nespresso.com/au/en/order/accessories/original/… Jun 22, 2021 at 10:58
  • Are you using fresh or UAT milk ?
    – Elfarto
    Jun 22, 2021 at 14:44
  • @Elfarto fresh 2% fat milk Jun 22, 2021 at 20:47
  • 1
    @LeopardSkinPillBoxHat can you add a comment to my answer explaining how it fixed your issue? I keep getting it downvoted somehow even when you have accepted it as the answer
    – Elfarto
    Jun 29, 2021 at 22:16

3 Answers 3


The short answer here is that that device is not up to the job.

Consider how microfoam is typically achieved in coffee shops compared to this device. Espresso shops use steam for a reason. Steam is a very effective mechanism for injecting both steam and air into milk while simultaneously agitating the milk.

Your device, on the other hand, heats the milk from the bottom and stirs it with a little paddle attached to a motor. The stirring action pulls air in and incorporates it into the milk via stirring.

The steam method is more effective at producing microfoam because you can control the amount of air injected. You have no control when using this device, so the device is designed to overcompensate. It uses a slow heating method and aggressive stirring to achieve a high degree of frothing because many people who use this type of frother are comparing it to a stick frother and not to a steam wand.


Welcome to the mystery that is coffee. I steam my milk. I have steamed about 5000 times since I bought this machine and I can’t get two in a row the same. Obviously I have yet to discover the secret. Advice?

Don’t overheat the milk. It changes the proteins

Big bubbles? Slam the container on the counter to burst them.

Swirl the container. This significantly stiffens the foam.


I have the same Aeroccino frother, I also use fresh 2% milk and my results are consistent with your first picture, can you try warming your milk on the microwave for about 15 seconds then running it through the Aeroccino and see if there is any difference ?

  • This helped me - warming up the milk seems to make the milk consistency much more consistent when I use the frother. Jun 29, 2021 at 22:44

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