I also add vinegar and a little olive oil. The vinegar not only helps the yeast but it helps the bread resist getting moldy. To much oil in the dough will make the crumb - from a lack of knowing the correct term - course and crumbly. I use no more than a Tbsp of oil in 6 cups of flour dough.
I use to have problems forming the final loaf (after the first rise). I always ended up with creases and cracks in the final baked bread. I was using to much oil when coating the dough for the first rise. I was handeling the dough to much at this point, folding it over and kneading slightly and the oil on the surface of the risen dough acts as a barrier and does not let the dough come together in the final rise - causing the creases. I now use a cooking spray very sparingly on the bowl and then use a paper towel to wipe it into a very thin coating on the bowl and just a spritz on the top of the dough.
After the first rise I just take the bowl turn it upside down, and thump it down on the counter top and let the dough fall to the counter - this is my punch down. I gently turn the mass of dough over so the smooth side is on top and let it sit for a min. or two. At this point I handle the dough as little as possible. If I am going to bake it in a bread pan I just put my open hands on each side of the dough and slowly bring my hands together to get the dough to the width of the pan - same for the length. Gently place the dough in the pan and let it rise.
If I am making a French bread I put my hands on the side and while bringing them together gently stretch the dough to the length I want. Cover and let rise for the second time.
Place in a 425 F oven 15-20 min.
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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.
Red Devil posted some good information about breadmaking that might be of interest to you. Post 423.