I've been making a lot of green smoothies (using a Vitamix), and they have a tendency to end up with about 2 inches of undrinkable froth/foam at the top. It seems a higher percentage of veggies vs fruit makes it worse, and spinach is particularly bad.

2 questions:

What causes this? (my wife suspects it has to do with the fiber not breaking down -- which seems plausible, but it's just a guess)

And what can we do to prevent it? Is there anything we can add to get them to more fully integrate?

A sample recipe, if it helps:

  • 1-2 handfuls spinach
  • 1 apple
  • 1" piece ginger
  • 1 persian cucumber
  • 1 stalk celery
  • juice of 1 lemon
  • Forgive me that I ask to too old a question, but what Vitamix model do you use?
    – Blaszard
    Commented Nov 26, 2015 at 11:37
  • No problem -- it's a vitamix 5200 (standard series). Scruffy's answer works perfectly for me, keep it slow and look for the air bubbling out (watch the video from his link below for a better example). Commented Dec 4, 2015 at 20:24

5 Answers 5


As Catohound already mentioned, it's a symptom of using a high speed blender. You may find this technique useful.

Tcrn the blender to its lowest setting and then slowly ramp it up until the top of the liquid just starts to circulate (usually around speed 4 or 5 on a Vitamix). As you run it at this low speed, you will see bubbles coming out in the center.

My wife and I do this with our Vitamix and it generally gives good results.

  • 3
    This would be a better answer if you summarized the technique rather than just linking to it.
    – KatieK
    Commented Nov 8, 2013 at 23:31
  • All right. I updated my answer with a relevant quote from the link.
    – Scruffy
    Commented Nov 9, 2013 at 20:58
  • The video from that link is especially helpful for seeing the technique (and, tried it this morning and got nearly the same result, and a much better smoothie). Accepted. Commented Nov 10, 2013 at 17:11
  • Glad I could help! Enjoy your smoothie. :)
    – Scruffy
    Commented Nov 10, 2013 at 21:12

I don't know how to solve it once it's happened, but it's caused by the high speed of your blender. I use an Oster blender and never have froth in my green smoothies, so maybe trying a different blender will prevent it. If you juice greens they get frothy, so it's not the fibre NOT breaking down - maybe the opposite. Pulsing the blender a few times at the end might get rid of some of the froth. I always pulse a few times at the end to get some of the incorporated air out of my smoothies. High speed blenders incorporate a lot more air than my blender does, though. Not sure if that'll cut it for you.


Add a tablespoon or two of chia seeds - they magically eliminate the froth.

  • Really? Chia seeds?
    – Jolenealaska
    Commented Jul 3, 2014 at 6:39
  • 3
    Add before or after blending? Commented Jul 3, 2014 at 17:35

Two major sources of foam are (1) air whipped into bubbles, and (2) insoluble fiber.

To help with #1, after blending everything the way you normally do, turn the blender to a lower speed setting for a few seconds to allow bubbles to coalesce and burst. Article with video.

For problem #2, you can

  • Reduce the sources of insoluble fiber (leaves, peels, apples)

  • Add some soluble fiber sources for a creamier mouthfeel (bananas, mangoes)

  • Add some oil to pop some of the bubbles. Ideally a healthful oil such as flaxseed oil or coconut oil, but if you don't want to impart any flavor regular neutral cooking oil will work. DO NOT use extra virgin olive oil because it will turn very bitter in a blender.

This article goes into more detail.


After blending, turn the mixer to low and add a few drops of canola oil. It will knock out the froth and replace it with a more "liquidy" product.

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