Yet another beginner proofing question

I protest! It IS right! You are making basically very good bread that needs a couple of changes to "take it to the next level". There's far too much basically bad bread eaten everywhere all the time. Your good-but-could-still-be-improved bread is already ten times better than what millions of people end up eating.

why not use all of it?   :)

How long does the levain take to peak?  Using it at peak?

A different score may get you a higher loaf.  

i am a sourdough newbie, too.  I was taught to do a second shaping.  Pre-shape once then bench rest covered for 30 minutes; Repeat the Pre-shape and bench rest;  then Shape the dough to create more surface tension and place topside down into a floured banneton; proof in the refrigerator until doubled and passes the poke test then invert into a Dutch oven to bake.  My bake instructions say to bake covered at 500 degrees Fahrenheit then remove the lid and reduce temperature to 450.  I do not know the temperature in Celsius.  I also preheat my oven and my Dutch oven together then wait an adiitinal 30 minutes after the oven has reached temperature to make sure their are no cold spots.  Dacor recommends this long preheating of their ovens.  I used to not wait.  Now, I do wait (sometimes 40 minutes) but my baking is more uniform.  Also, I had to have my ovens recalibrated.  One was off 25 degrees and the other 10 degrees.  Now, my baking meets most of the recipe oven times.  Hope this helps but take it with a grain of salt, I am new to baking bread.  

You wrote "I add the salt and levain after the hour..."

What actually happens when you do this?  I assume there is some mixing.  By hand?  Stand mixer?  For how long?  It is possible that you could develop a little more gluten at the beginning.  I found that I was not working the dough enough (I mix by hand), and when I finally did begin doing that, my dough had the necessary gluten network to support more oven spring.  (By the way, there are some excellent videos on Trevor J. Wilson's website, which is breadwerx.)

You also wrote "Then I do turns every half hour for 2 hours and let it bulk for 2 more hours"

What is the temperature in your kitchen?  I live in Connecticut, and during this time of year I cannot expect a complete bulk fermentation in my kitchen in only four hours.  Are you watching the clock and not the dough?  You should look for signs of good fermentation.  Those will include expansion of the dough, visible bubbles along the sides and bottom of the container, perhaps even bubbles visible from the top view, a dough that feels poofy and pillow-like.  If you are relying on the clock to measure your bulk fermentation, stop doing so.  I also found that I was not letting the bulk fermentation go long enough during the winter months.

I agree with the above comments that you are on the right track and will likely find that you are not that far from the results that you are hoping for.  Keep asking questions.  Happy baking.

Ted

under proofed.  What does the dough look like after the bulk fermentation?  Has it risen a lot? A little? about what %age?   It's important to wait for the dough to do it's thing and not rush it.

Also, your hydration is pretty high.... like 78% I think.  What's it like to work with? Sticky? 

hester

p.s. that wasn't a small novel, not even a short story.  The more we know the more we can help.

With a stone, you probably need a lot of extra preheating. If you don't heat the stone up for a lot of extra time, it may actually be a disadvantage to have it.

Try to get your proofing environment up above 85 - 88F. You could use an incandescent light bulb for this.