I'm using Andrea Tortora's recipe, which I've used successfully for a handful of bakes over the years. Until recently, I wasn't familiar with lievito madre and so I typically just used a 100% sourdough starter when the recipe calls for fresh yeast. I've also only used King Arthur bread flour for this recipe.
When I learned about LM, I decided to make one and use it in the recipe. I've also started using King Arthur Lancelot flour since it is stronger than the bread flour I typically use. For the LM, I've been consuming everything I can find on this site related to panettone, LM, and mwilson. I also picked up a copy of Sourdough Panettone and Viennoiserie. I am all in, and my interest / obsession with panettone goes back way before I started baking maybe a decade ago.
Since making these 2 changes, I've had a very specific issue with my dough.
3 refreshes of the LM go well and triple in less than 4 hours. It tastes like apples without a hint of sourness, but I've never checked the ph or anything. First dough comes together nicely, though admittedly takes me well over an hour in my KA Professional. Windowpane on this dough is beautiful.
Dough bulk ferments at about 80 - 85 F for 10-12 hours. I start mixing the second dough after the first triples.
The second dough is where the issue is. Everything goes well up until I add the butter. Even the adding the butter goes well until I add the last bit of it, at which point the dough completely falls apart. No gluten to speak of. It's like cookie dough.
I realize it's probably over mixed. I've tried this recipe with LM and King Arthur Lancelot flour twice and both times had the same exact problem. I will say that the first time, I was very aggressive with my mixing speed and did not control the temp of the dough well. This time was different - I never went above 2 on my kitchen aid and I kept an ice pack against the bowl to keep the temp down,yet neither of these adjustments fixed my problem.
Failing at this is exhausting. I keep my LM in the fridge and begin strengthening it 3 days before making the first dough, with 3x refreshments per day and bound overnight storage at about 60 F. It's a long process to then fail right at the end!
Any ideas what the problem might be? The 3 changes are LM and a new flour. I'm guessing one of the two is the culprit.