In a deep bowl, measure our the rye flour. Make a well in the centre. Dissolve the yeast in the water & add to the bowl. Add salt, oil & vinegar. Stir vigorously. Add the white flour. Knead well till the dough is pliable. Form into a round bread. Use a brush to oil the surface & set in a 23 cm round pan. Allow to double in size. Preheat oven to 180ÂșC & bake for 1 hour 15 minutes.