Well … today is an (inadvertent) sourdough croissant experiment!
The variable I adjusted was proving time.
Basically I forgot I had them in bags proving and got buried in client calls. Two hours later I go “Oh no!”
Normally I take my croissants out of the fridge where I had left them covered in the morning, put them in proving bags for a couple of hours before baking.
Typically this is about 2.5 – 3 hours depending on my room ambient temperature.
Not this time!
I left them out over 5 hours!
They are certainly “proved”.
I baked at my normal 375°F (convection) 15 minutes.
Another small experiment was introduced because I forgot to remove the small pizza stone from my oven. Agggghhh!
First tray actually looks pretty good!
I baked the second tray and got similar results.
Eureka!!!
Evidently I haven’t been proving long enough!!
Wow! I am thankful that I had this (inadvertent) experiment today!
Baked By Bear Sourdough 
They look great! Impressive laminations!!
I constantly underestimate proofing time! Mainly because I want to dive in and eat!
I notice from your picture the inner coil of the croix in slumped towards the bottom. I remember being told this was from slightly over proofing. Personally I prefer over as under gives a very tight texture!
I might give the baking stone a go…
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