Water versus yeast in dough

Most if not all of my sourdough breads turned out rather dense. Some actually were dense to the point of being almost impossible to chew, and even the softest was only marginally fluffier than pumpernickel. I developed two alternative theories as to why that would be:

1. My sourdough just isn't that good at raising the dough. After all, sourdough is based on wild yeast which may not be as good making bubbles than a yeast bread in the lab for the expressed purpose of producing lots of bubbles.
2. I am not using enough water. My low water dough works and feels like play-doh which is great. But it may be the yeast paying the prize for my non-stick dough by not having enough water to develop.

Subsequently I made a bread with extra water and it was my fluffiest bread yet. I therefore concluded that theory (1) was bad and theory (2) was good. Of course, that's not entirely valid: (2) is good, but (1) could be good also. As a matter of fact, it could be that water content plays some role but the yeast plays an even bigger role. I was aware of my logical leap at the time of the conclusion already, and it has bothered me ever since.

So this weekend I decided to launch the control experiment, by first making another batch of the dry dough:

• Mix the sourdough starter with four cups of flour and two cups of water. Allow the starter to ferment that dough until the dough is thoroughly bubbly.
• Add another four cups of flour and four teaspoons of salt, work everything into my typical non-stick dough.

This is the dough that I used to make my first breads from, like the cannon ball and the turtle. This time I split the dough into two halves. One half I left as it was (my control experiment), to the other I added a pack of instant yeast, the kind that doesn't need to be started out with warm water. I thoroughly worked the instant yeast into its allotment of the dough.

From that point on, I once again treated both batches the same:

• Knead the dough thoroughly then let it sit over night so the dough can rise as much as it wants to.
• Knead the dough one more time, form the bread loaves, and put them into their oiled forms.
• Bake the loaves while periodically spraying them with water until they appear to be done, half an hour at 400°F in each case.

Here is the result:

Yes, me too. There is no discernible difference at all. Both are the size of a large dinner roll. But make no mistake they each have the weight a small loaf of bread is supposed to have, about 10 ounces.

And it wasn't just a fluke because I made three loaves each. If there is any difference at all it is not in the size of the loaves. Rather, the "sourdough plus yeast" bread has a few more cracks. I could speculate as to why that would be but I won't.

What we can now pretty much take for granted is the following: My dough is too dry and that's  the limiting factor right now. Nothing else will make a difference unless I use more water in my dough first.

We do not know yet whether sourdough is just as powerful fermenter than baker's yeast. It could be that baker's yeast performs better once the water constraint is removed. Which would make another neat experiment- after I am done eating those six high-density loaves resulting from this experiment, that is ---