Mix the flour, salt, sugar, aniseed, and yeast in a large bowl. In a separate jug combine the grape must or grape juice with the warm milk, melted butter, and eggs.
Pour the wet mixture into the dry ingredients and knead until you have a smooth, elastic dough. This should take about ten minutes if kneading by hand or about five minutes in a stand mixer with a dough hook.
Place the dough in a greased bowl, cover with a cloth, and allow it to rise in a warm place until doubled in size. This will take about an hour.
Once risen, knock down the dough and divide it into small pieces. Shape each piece into a ball and pack them snugly into a greased loaf tin or baking dish.
Cover the tin and let the shaped dough rise again until doubled in size, about thirty to forty minutes.
Bake the mosbolletjies in a preheated oven at 180°C for about thirty to forty minutes, or until golden brown on top and baked through.
Serve warm with butter, or allow them to cool completely if you plan to cut and dry them into rusks.