Take the 2-minute tour ×
Seasoned Advice is a question and answer site for professional and amateur chefs. It's 100% free, no registration required.

When I poach eggs, an off-white foam/scum forms on the surface of the water and sometimes attaches itself to the egg. Does anybody know what causes it, and how I can avoid it?

EDIT: I use malt vinegar rather than white vinegar, which I think discolours the foam/scum and makes it look more unpleasant, so I think I'll change to white vinegar.

share|improve this question
add comment

4 Answers 4

The scum is similar to that which forms on stock; it is made of proteins which have detached from the larger protein matrix in the egg, forming a secondary protein matrix on the surface of the water. I know of no way to avoid it, but there is absolutely nothing wrong with it. If your concern is cosmetic, I wouldn't worry; it largely disappears as the bubbles pop. If you really want to get rid of it, give your poached eggs a quick rinse under warm water before drying and plating.

share|improve this answer
add comment

A few tricks I've seen used in restaurants:

  • Add a bit of vinegar to the water (supposed to cut scum, keeps egg together better)
  • Increase the surface area of the pan (many restaurants use a large rectangular pan for poaching)
  • Use more water (reduce the ratio of protein bits to water)
  • Slide the eggs in more carefully and use fresher eggs (less protein separates)
share|improve this answer
add comment
up vote 1 down vote accepted

After much experimentation, I have found that the keys to avoiding the off-white foam/scum are:

  1. Use eggs that are as fresh as possible, as this greatly reduces the amount of scum.
  2. Use white vinegar instead of malt vinegar, as this avoids discolouring the scum, which makes it more visible.
share|improve this answer
add comment

Instead of poaching, you could try steaming. It is less 'aggressive' but you should calculate about 20% more time for the same result.

Also, you could push a needle trough the shell at the flat of the egg. There is a small air chamber there and the pressure can escape without shedding egg-white. Be careful to not push the needle too far in, as you'll rupture the membrane...

With a fresh egg, the chamber is better defined, so you'll have less trouble there.

share|improve this answer
add comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.