The simplest way to prepare the egg medium (for egg tempera)

Here's the simplest (and most amateurish) but efficient :) way to prepare your egg medium:

You will need:

An Egg yolk, equal quantity of vinegar, a plastic mesh strainer, two  glasses, and a container to store the liquid

Put the egg yolk and then the equivalent amount of vinegar in the plastic glass (with a couple of droplets of water) mix them well and afterwards  transfer them in the other glass, through the plastic mesh strainer in order to filter the yolk sack.

Finally, store in a plastic container with a  nose tip  so it would be easy to use. It can stay in refrigerator (when not used) and may last even a week.