Professor Calvel set the 2.5% outer limit for fresh yeast for basic French bread. In just about all of the basic French bread dough recipes in his book, he calls for less than 2% fresh yeast. The only time he goes to 2.5% is for the straight dough method with intensive mixing, which he said he did not recommend. Professor Calvel also has several recipes in his book for specialty breads that go as high as 4% fresh yeast, but these seem to be for breads where it is desired to achieve short production times, typically under three hours. We would call those doughs "emergency" or short-term doughs if they were to be used to make pizzas. I did not find any dough recipes that call for cold fermentation of the final doughs although Professor Calvel allowed for cold fermentation of prefermented doughs. There is only one recipe in the book for pizza, and that is for a pissaladiere
, which is basically bread dough (using a preferment in this case) that is used to make the pizza.
The question of similarity between bread dough and pizza dough has come up on several occasions on the forum and I think that most will agree that there are many similarities. Of course, there are some differences, such as knead times and degree of gluten development, fermentation protocol (e.g., room temperature vs. cold fermentation), form factor (flat for pizza and much greater height for breads, other than flat breads), and special baking steps (such as using steam when baking breads). However, at the science level, there are many common factors shared by bread and pizza doughs. To what extent the differences are affected by fresh yeast and the amounts used, and the nature and duration of fermentation, I have no idea. However, I know that for certain pizza doughs that are to be made in a short period, such as Chicago deep-dish doughs and cracker-style doughs, it is quite common to use considerably more yeast, in whatever form, than for most other doughs. Since these doughs are often run through commercial sheeters or rollers, the gases are forced out of the skins but what remains is the flavor profile of the yeast, with a dominant yeast flavor in the final product that is distinguishable from the flavors contributed by byproducts of fermentation. Some people like that type of flavor, but others often do not.
The debate about the use of fresh yeast versus the other forms of yeast (IDY and ADY) has been with us for as long as all three forms of yeast have coexisted. Cook's Illustrated says that fresh yeast produces more gas than the other forms of yeast. However, as I noted in Reply 1 at http://www.pizzamaking.com/forum/index.php/topic,5894.msg50515/topicseen.html#msg50515
, when the AIB, where Tom Lehmann works, ran tests using the three different forms of yeast, they could not detect the difference in the final products. I suspect that they used cold fermentation rather than room temperature fermentation since that is more common for the professionals that AIB tends to serve most.