As ZONERS we use egg whites and not egg yolks.
The problem is that separating egg white from egg yolk using the cracked egg shell in half and
transferring the egg yolk back and forth between the two halves is not always easy
and even being careful, sometimes ends up with yolk in the whites.
My dad sent me a link to a video that is an amazing way to easily separate egg yolk from egg white.
However, we are not supposed to post other links that lead you away from this website.
So, I will have to try and describe the method, instead.
The video link is in Chinese, but it is so easy to understand visually, it should be easy to describe.
The text roughly translates: Handy! How cleverly separated egg yolk:
Crack the egg and empty the entire egg (yolk and white) with yolk unbroken into a small bowl.
Grab an empty water bottle and gently squeeze it.
Put the lip of the water bottle over the center of and touching but not breaking the egg yolk.
(This does not work if the yolk is broken.)
Ease off the water bottle and let the suction pull the egg yolk into the neck of the bottle.
Gently squeeze the water bottle over a second bowl to push the egg yolk out, again unbroken.
Wha-La - easily separated unbroken egg yolks from their whites.