I used butter, not shortening, to make these, and replaced half the flour with whole wheat. They were lovely, although a little soft and crumbly. I got 24 medium sized muffins from this recipe, and they were baked in 25 minutes. I made half without and half with rosewater. Both were very good, although I think I prefer them without. Blueberries have a tendancy to sink to the bottom of baked goods. To avoid this, save out one third of them, and gently spoon them over the batter once it is in the pans. They will still sink but they won't make it down quite so far.