Help with the holes on between the crust and crumb

Toast

 

New sourdough bread baker . 4 loafs down.My first one was flat , the second one was a hockey puck , the third one was decent  and the fourth one has been the best of the lot .

For the 3rd and  4th bake i used the fullproofbaking basic sourdough baking (https://www.youtube.com/watch?v=HlJEjW-QSnQ)

This is what i did for this bake 4

Janie Mill  Red fife (WW)

70g

Janies Mill High protein flour

255g

Water

253g

Leavin

65g

Built 1:2:2

15g :30g :30g

9:30 PM previous night used on dough at 7:30 AM

(10 hour - Just collapsed)

Salt

7.5g

 

Bulk temperature 72 - 74

 

6:15 AM - Autolayse flour and water

7:45 AM - Add leavin

8:15 AM - Add salt

8:50 AM - table stretch and fold

9:20 AM - Lamination

10:13 AM - 1st stetch and fold

11:05 AM - 2nd strecth and fold

11:50 AM - 3rd stretch and fold

1:00 PM - preshape

1:20 PM - shape (boule)

1:45 - Fridge retard

 

I noticed that both in my 3rd and the 4 th bake  i have a big hole between my crust and crumb.

My 3rd bake was similar method only with 100% whole wheat  KAF.

 

Could this be over proofing or shaping technique and  why am i not getting open crumbs?

Bake 3 - 100% WW

 

Bake 4

I'm still working on the oven spring and ear .

The crumb is pretty good for WW, you are not going to get a white bread-type open crumb.  Bubbles comes from insufficient degassing and (may be) heavy-handed shaping.