Ever tried separating egg yolk under time pressure? What was your succes rate?
Ever tried separating more than 10 eggs without getting bored?

This instructable will show you how to make a device that separates egg yolk from egg white. It is based on the principle that egg yolk has a larger density than egg white. Once the egg plunges into the separator, egg white will come oozing out leaving egg yolk behind.

NOTE 1: Sometimes the egg white may contain some yolk. If your recepy requires pure egg white, it might be ruined. The device is a great yolk separator but sometimes a poor egg white separator.

NOTE 2: Whilst writing this instructable someone pointed out that a similar device is already for sale in specialised shops. However, since mine is nicer and for free, I decided to publish anyway!

Step 1: What Do You Need?

You will need a cup that meets the following specification:

1. Stainless steel or plastic (food grade) for hygenic reasons.
2. Fairly wide top (opening) as you have to pour the egg into the cup. If it is to narrow, you'll end up spilling part of the egg. An opening of 6 cm works fine.
3. The height of the cup should be so that it can easily contain an entire egg.

4. A fine saw to cut stainless steel.
5. Optional: an iron vile.

Straingely enough, the shape of a large egg seems ideal.

Step 2: Making the Device

From experience, an average egg yolk is about 30 ml (depends on the size and class of egg).

Take a conical or spherical stainless steel cup. In my case I used an egg timer (how appropriate) that didn't work anymore.

Get the top of and fill it with 30 ml of water to mark the cutting line. If your eggs are larger / smaller, adjust this volume.

Mark the 30 ml line, take an iron saw and make a cut about 3,5 cm long and 0,5 cm wide. Make sure that the edge is not rough (vile / sand optionally).

Step 3: How It Is Operated.

You will have to be able to open an egg with one hand as most cooks can...

With one hand break the egg on the edge of a cup (this requires a bit of skill) and let the entire egg plunge into the separator. You will notice that once the egg is dropped into the separator, the egg yolk will sink to the bottom beneath the cut and remains unharmed. Especiallly since the egg yolk is contained in a skin which makes it sink as a "homogeneous ball".
Meanwhile, the egg white will immediately start to overflow through the cut.

Now gently make circular motions with your wrist to rotate the egg white towards the cut. After spinning it about 3 times, most of the white is out.

In fact the principle of this device is the same as separating yolk in the traditional way: the egg white is cut over the edge of the remaining egg shell.
However this device works faster as it works in 1 step.