The white foamy type might be due to something else and not Pseudo but would not hurt to test. I also have the white foamy but along with it plenty of brownish colored plugs. The brownish colored is typical of Pseudo, But the white foamy is not typical. I have read of one other person who mentions it as well. Internet mentions causes to be COPD or Heart or GERD. My pulmo just dismisses it as air getting in during the nebulizing process or some such thing. But I think he is just not sure. The other person who mentioned having this said her Dr was not sure of the cause either. With so much volume you might at least get your heart checked and or gastro Dr.