I've been trying to figure out my issues with panettone baking, not enough oven rise. I believe it is quite misleading to blame a lot of the problems on the starter, I believe this is not the issue most people have. I might've figured out the problem from a little hint from a pro-baker: panettone loves a spiral mixer. I do not have one. I do have strong flour, correct temperatures and fermentation, a nice windowpane, smooth and glossy second impasto. However, passing the windowpane test only tells you that gluten exists and can stretch. Panettone needs something else, elastic recovery. My dough stretches beautifully great extensibility… but relaxes immediately. This seems the smoking gun. In my worst attempts, second impasto looked correct (to me), but baked like a cake. This tells me gas expands inside a fat-starch matrix, not gluten. My gluten is too plastic, not too weak. Because I have a stand-mixer it is very difficult to properly emulsify, the gluten network is over-plasticized by fat/yolk. Giorilli's formula that I've been following is also quite heavy on fat.
The question is what can I do to solve this, because somehow it appears to be possible to make decent panettone with a stand-mixer? I've read a suggestion about saving some water from the first impasto and adding it in the end. But this will almost certainly make elasticity worse, not better. Water added after fat does not integrate into gluten, it increases extensibility without rebuilding elasticity.
I'd appreciate any tips on how to successfully incorporate the yolks and butter with a stand-mixer.
But I have successfully made Pannetone in my Kitchen Aide stand mixer. I used a tip from "The Bread Baker's Apprentice" that said to do the first mix (with the dough hook) until you hear a slapping sound and the dough cleans the bottom of the bowl, and then add the yolks and butter slowly smash butter with your fingers so it is about the same consistency as the dough - put in very slowly waiting until each chunk is incorporated, and then wait until the mixer makes that telltale slapping sound again.
It has worked for me. Good luck!