The Food Lab: Better Home Cooking Through Science

But take a look at your poached egg problems, then ask
yourself a couple of questions. When do your poached eggs
work? That answer is easy: when the eggs are fresh. The
older an egg gets, the weaker the membrane that surrounds
the white becomes, and the more likely it is that your egg
will spread when it hits the water. This leads us to our first
rule of poached eggs: use very fresh eggs.
What exacerbates the possibility of the white falling
apart? Agitation. The more the egg shakes and shimmies,
the more likely it is it’ll separate. It’s standard practice to
poach eggs in simmering water, but we already know that
eggs will coagulate even at a subsimmer, so there’s no
reason to keep the water anywhere near a boil. Bring it up to
a boil, then turn the heat off when you add the eggs.
But what if you’ve got fresh eggs and a subsimmering pot