Warm flour slightly in a large bowl. Mix yeast with 3/4 cup of the warm water and brown sugar. Combine flour, powdered milk and salt then rub in the margarine. Lightly stir in liquid yeast mixture then put in a warm place to rise, about 30 minutes.
Turn out dough out onto a lightly greased bench then knead well. Add more flour or water if necessary. Set in a lightly greased bowl until doubled in size, about 90 minutes.
Knock down the risen dough, then divide dough into to two greased and floured tins. Allow to rise for 30 minutes more, in a warm place. Bake at 230 degrees C for 10 minutes, then reduce heat to 200 degrees C then bake until loaf is cooked though, 20-30 minutes.