I do appreciate the replies and thoughts on it. I guess I cold have done a larger photo. I only asked because from looking at other BIAB threads asking the same question it seemed SLIGHTLY course.
Now for the info you've all been waiting for. This was my first BIAB ever and it was for a 1 gallon batch so I mashed in 2 gallons of water and got the following efficiencies from Brewer's Friend using my equipment profile:
Ending Kettle: 92% 33.5 ppg
Brew House: 80% 29 ppg
I did rinse the grains with 2 cups of wort after the mash out while suspended above the kettle, I also squeezed the grain bag for a minute. Is this pretty good?
I'm puzzled
How did you lose 12 percentage points from end kettle to fermentor. Something seems awry
What was the grain-bill?
What was the OG?
What was the volume in the fermentor?
These will give you your BH efficiency.
With any crush, doesn't matter what system you use, BIAB or otherwise, you want the grains milled as finely as you can without causing any reductions in lautering efficiency.
Crush too fine using a braid or false bottom as a manifold and lautering efficiency can be reduced. Similarly crushing too fine in a grist with a lot of husk-lesss grain like wheat or rye can have similar consequences.
If you crush finer, all else being equal it will take less time to achieve maximal conversion efficiency.
The question as to why BIAB' ers crush so fine, which seems to be a source of angst for some in the thread is because the manifold (the bag) is un-blockable owing to its massive surface area relative to a false bottom or braided hose. It is therefore much more suited to a finer milling.
The appropriate question should be why aren't you milling finer if using an un-blockable manifold.
Grain being crushed too finely is often cited as source of tannins and astringency. This is not the case in my experience. Temperatures in excess of 170F and a pH in excess of ~6.0 are needed to achieve this.
On another note. OP sparging with wort is entirely ineffective as the concentration gradient of sugars between the wort soaked grain and your sparging liquid is zero. No sugar will move as this would disobey the fundamental laws of physics.
It would be like dyeing a white t-shirt in a water/dye mix and then using more dye/water mix to try to rinse out the soaked in dye from the t-shirt getting it back to white.
If you are bothering to sparge, sparge with water not wort of the same gravity.