Thanks for the added information, my bread machine book says to add vinegar, but not why and I will cut back on the oil, as I have been far too generous with it.
Good post, thanks for sharing your knowledge.
In other breads you can also add milk or buttermilk both need to be scalded first (heat just below boiling) this kills enzymes in the milk that reduce yeast activity. Scald even pasturized milk.
When using buttermilk do not use more of it than half the liquid called for in the recipe. Makes the bread tender with a finer texture, helps the bread last longer and adds a nice taste.
You can add up to 1/4 cup of mashed potatoes per loaf. Makes the bread lighter and gives a finer texture.