1
$\begingroup$

If I fill a glass jar with water, vegetable oil, and dish soap, then mix it until the oil is completely emulsified, will the mixture stay emulsified indefinitely?

Assuming the dish soap and oil are chemically stable and do not degrade or otherwise change over time, if I left the jar on a shelf for years, would it remain emulsified? If I heated the jar up (but not enough to boil or decompose anything), or froze it, or shook it, or put it in a centrifuge, would it stay emulsified?

Improve this question
$\endgroup$
7
  • $\begingroup$ I'm gonna go with yes. $\endgroup$
    – Todd Minehardt
    Commented Sep 23, 2021 at 21:38
  • $\begingroup$ No, it won't remain stable. You cannot have any arbitrary ratio for a stable emulsion. Recall the types of emulsions oil in water vs. water in oil. If you notice, dishwashing soap has dozens of other additives to stabilize the dishwashing liquid and prevent phase separation. Nobody can make a prediction what will happen after boiling heating. $\endgroup$
    – ACR
    Commented Sep 23, 2021 at 23:31
  • $\begingroup$ It would be nice, if you could add some context. What is the background of this query? $\endgroup$
    – ACR
    Commented Sep 23, 2021 at 23:32
  • $\begingroup$ Mostly I am curious. There was a comment chain on reddit about washing oily things with soap and someone asked if the oil would become unemulsified. The context seemed to be about pouring grease/oil down the drain being bad vs cleaning up oily dishes being good. That made me wonder, under what conditions if any (applicable to drains and sewers) would emulsified cooking oil become not emulsified. $\endgroup$
    – Ethan Reesor
    Commented Sep 23, 2021 at 23:54
  • $\begingroup$ Ethan, Oil/grease solidification in sewers is a completely different case. Sewage water does not contain enough detergency to keep oil separated and also think of other junk (very complex biology and chemistry there). Also think of precipitation of fatty acids/soaps via calcium and magnesium ions. I lived in a very cold country and it was prohibited to discard cooking oil down the sink. $\endgroup$
    – ACR
    Commented Sep 24, 2021 at 1:37

0

Reset to default

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Browse other questions tagged or ask your own question.