Adding butter to panettone dough all at once?

Most recipes I see for panettone (and really most enriched doughs) specify that butter must be added bit by bit, only when the last bit is fully incorporated.

But I recently got ahold of Thomas Chambelland’s Sourdough Panettone and Viennoiserie, and every recipe in that book asks to add the butter all at once and only mix for a few minutes! I have a Kitchenaid at home but the authors do say that planetary mixers are suitable, so I don’t know if that would be the difference.

I know there are many panettone experts on this forum—does anyone have insight into this discrepancy? I’ve been having a string of panettone failures and I’m looking for any possible avenue for improvement.

I would have to go back and check my copy later when I have time to be sure, but I'm fairly sure that the butter is added in three stages for most recipes, at least for the secondo impasto.

On mixing times, my experience was that - despite the official KitchenAid recommendations - "low" speed is 2 and "high" speed is 4. Depending on the size and hydration of the dough at any given stage in the process, it may also be helpful to use the paddle rather than the hook. The same general principles apply as for making high hydration ciabatta or pan de cristal.

Butter works against gluten development (a critical component in Panettone). Hence, why most instructions advise to add butter in stages. If you are making Panettone by hand then adding in stages is essential. If your mixer is great at gluten development then you can get away with adding it all at once - I do. However, I suspect most home mixers are designed to be generalists and suffer on gluten development front and would benefit from keeping to the advice to add in stages and wait for each patch to be fully incorporated.

The main difference I’ve seen with panettone recipes is whether the butter is added before the yolks or after the yolks. Most recipes now add about 1/3 of the yolks, then all of the butter, then the rest of the yolks. Adding a little yolk loosens the dough a bit and makes it easier for butter to incorporate (think of the dough like an emulsion).

The most important part of mixing is to really develop the gluten network before adding any enrichments. You have to mix it more than you think is necessary at that point. This will heat up the dough, particularly in a planetary mixer (I use a spiral). Don’t let the dough temp get much higher than 26C. Butter (if cold) can help bring down the dough temp. I slice sticks lengthwise, then feed them in while the mixer is running, one after another. Then mix until they are all incorporated.