Grandma's Egg Liqueur

Rinse bottles and, if used, the funnel thoroughly with hot water and let them drain well.

Bring the whole milk with the vanilla sugar to a boil in a pot and then let it cool briefly.

Beat the egg yolks with the sugar in a bowl until pale and creamy, until the sugar is completely dissolved.

Slowly pour the warm milk into the egg yolk–sugar mixture in a thin stream while stirring constantly.

Finally stir in the rectified spirit until everything is evenly combined.

Pour the egg liqueur into the prepared bottles, close them tightly and store in the refrigerator.