How to make tempera for writing byzantine icons

The board is prepared as underpainting (look here how to do it).
Now I sketch. Sometimes first on paper, and sometimes immediately on board. With a pencil, gently, main outlines. For example like this:

The White Angel - sketch on a board for an icon of the Resurrection

Patterns of icons do not come, of course, from my imagination. An icon is a theology inside the image, so I am modeled on the old masters, not to introduce theological untruth.

I write icons with yolk tempera (egg tempera), like our ancestors. I make the tempera by myself, mixing mineral, loose dyes with yolk of and egg and white wine. I buy the dyes in shops for artists.

Making a binder from egg yolk and white, dry wine

I separate yolk from the protein and then puncture the membrane of the yolk with a knife. The interior of the yolk I pour into a jar. The same thing I do with a few next yolks. Then I add white wine in a ratio of 1: 1 (the same wine as the yolk) or 1: 2 (2 times more wine than egg yolk), or something in between these options.

Binder for paints can also be done by mixing egg yolk with vinegar half and half, and then adding 2 parts of water.

Loose dyes I mix with the binder on a pallet, adding different amounts depending on the needs. There is not any strict rule. I paint putting several or even dozens of translucent, thin layers. From time to time I cover an icon only with a binder. Ready icon I put off for 3 - 6 months to completely dry. After this time, I cover it with varnish.

Ready Icon of the Resurrection