Why so much yeast in this Panettone recipe?
I want to do this bread this afternoon, but I'm surprised it uses 3 packages of yeast and 3 cups of flour.
There is no mention of a problem in the comments, but I've never seen so much yeast used before.
I think it's the quick rises. Both are just half an hour to 45 mins. Peter Rinehart's pannetone is daunting and you have to start a week or two in advance, unless you have the right yeast but it uses much less, despite the fat and sugar because yeast reproduces in that time. IMO, it makes a better bread, though far more time consuming.
#1 So it rises fast and big.
#2 because yeast can be sugar intolerant (there is sweet dough specific yeast available, FWIW)
#3 1 and 2 are co-dependent. An extended rise time due to sleepy yeast and/or sugar and fat hindered rising (or purposeful retarding) changes the character of the dough, and especially so with sweet doughs.
Not sure i understand the exact chemistry, but breads with a large quantity of eggs, sugar and/or fat, such as a panettone or brioche require more yeast to rise than lean breads. One reason is that fat (from the eggs in panettone) coats the proteins in the flour and keeps them from bonding with water to form gluten, which is what traps the CO2 from the yeast to make bread rise. High sugar content has a similar effect on gluten formation .
Note that very lean breads (e.g., french baguette) are very airy and are made using relatively little yeast and a long fermentation. The (relatively) high amount of both fat and sugar in panettone may also inhibit the metabolism of the yeast and reduce its production of CO2, so you get a double whammy.