RE: Using a cooler and the walls sweating. Was the lid closed all the way or tight? What if you try cracking the lid with a spacer to allow the moisture to escape. Would that work? Amazing looking pies Omid. Did you take any pictures of the crumb? Can you do that next time you are there? Any guesses at their hydration level? Thank you for sharing your experience.
Dear Chau, your insatiable curiosity amazes and inspires me! I would not be surprised if one day in feature I come to learn that you, like Pasquale Makishima, have won the pizza championship in Naples. In regard to the Coleman cooler that I used long time ago, its lid was closed all the way. Cracking the lid with a spacer is definitely an option, which I implemented many times to increase the interior temperature. However, if I remember correctly, the iced-water bottles inside the cooler kept causing aggregation of moisture along the walls and the floor inside the cooler. I remember that sometimes the excessive sweating inside the proofing tray itself would annoyingly change my dough recipe in terms of the hydration percentage. Naturally, the sweat is contingent upon a number of factors: humidity levels, temperatures, and etc. in the room and inside the cooler. In respect to the Bruno pizzas, I neglected to take pictures of the crumbs, which were quite soft and fluffy, like a croissant. One piece that I saved, keeping it inside my refrigerator, is still maintaining its softness. I will take some crumb pictures next time. At last, in terms of the Bruno dough hydration level, my best educated guess would be equal to or over 60% or 61% but lower than 64%.
By the way, I recall reading somewhere that you were told the charred bubbles and/or spots on Neapolitan cornicione are signs of "over-fermentation". To my thinking, that defies the logic of fermentation, depending on how the term is defined. I am suspicious of an over-fermented dough engendering wholesome blisters within a 60-second bake in a Neapolitan oven. Please allow me to explain as far as my limited knowledge can guide me forward in this highly complex subject, which I had never consciously given it a whole lot of thought. And, the model that I will propound below probably won't be free of flaws. Hence, I would appreciate any efforts that would ameliorate or rule out the model.
The two principal chemical constituents of wheat flour are "starches" and "proteins". Basically, once a dough (composed of water, wheat flour, salt, and fermentative agent) is formed, the natural amylase enzyme of the flour is activated under proper conditions such as the right range of temperatures and hydrations. Once activated, the amylase enzyme commences to convert the starch content (the complex sugars) of the flour into simple sugars (such as dextrin and maltose), which are consumed and digested by the yeast cells in the process of fermentation. In fact, the simple sugars fuel the process of fermentation. To be more particular, the starch is composed of long carbonic chains of molecules. The amylase enzyme breaks down the molecular structure of these long chains into shorter chains, known as "dextrin" and "maltose" sugars. The maltose, consumed by the yeast, contributes to the process of fermentation, and the dextrin conduces the baking process. Hence, the amount of amylase enzyme present in flour is quite critical, while the conversion of starch into simple sugars plays a pivotal role in fermenting the dough and baking it into pizza crusts. Deficient amount of amylase in dough can lead to slow fermentation, whereas high amount of amylase can result in over-fermented dough that becomes stiff and gummy.
Now, what is the role of salt in relation to fermentation and charred bubbles? Salt seems to play an evasive role in the crust formation and coloration. Inasmuch as salt slows down the enzymatic processes (essentially decreasing the rate at which amylase converts the starch into simple sugars) and inasmuch as salt reduces the fungal activities (essentially diminishing the rate at which yeast cells consume and digest the simple sugars), by the time a pizzaiolo feels the dough balls have been fermented enough (before stretching them into dough discs) hopefully there are enough residual sugars
(unprocessed by the yeasts) left in the dough discs that can form those elusive bubbles on the cornicione! In a saltless dough, the yeast would rapidly deplete the sugars; hence, the dough would become bloodless and produces pale, albino crusts.
Based on the above premises, I hypothesize that a Neapolitan dough that contains adequate levels of the simple sugars
—in addition to containing certain hydration levels, density levels, and reposed glutinous tension levels, which are beyond the amount of time available to me to explore at the moment—is a necessary precondition for formation of the charred bubbles, spots, and/or dots on the cornicione
. When a dough disc is subject to intense heat in a Neapolitan oven, the residual sugars
that are left unprocessed in the cornicione become caramelized and more kinetic (mobile). Hence, they congregate together (like drops of water attracting each other) and turn, under the intense heat, into charred blisters, spots, and/or dots in various locations on the landscape of the cornicione and crust. (As the German philosopher Friedrich Nietzsche says, "Come, assist, complete, bring together what belongs together. . . !") An over-fermented dough may not have enough residual sugar left in it to turn into blissful blisters.
A couple of days ago, I did two ad hoc, not fully scientific, experiments that may shed some light on this issue. The first experiment involved baking 2 small dough discs made with the same exact recipes, portions, and techniques. (See the pictures below). The left dough disc was over-fermented at room temperature for 60 hours while the right dough disc was fermented at room temperature for 10 hours. Both dough discs were simultaneously exposed to 500° F for 5 minutes. Notice the over-fermented dough, in the picture below, did not brown much, perhaps because all the sugars were depleted by the yeasts during fermentation.
The second experiment involved making two piles of a mixture of dextrin and maltose (50/50), except the left pile contained few drops of distilled water. Both piles were simultaneously subjected to 500° F for 5 minutes. In that duration, the water quickly absorbed all the sugar particles in the left pile into one almost amorphous mass which began to boil in an agitated manner, while the particles of sugars in the right pile began to liquify, caramelize, and pull one another into a single, globular, tar-like mass. The smell of the smoke caused by the reaction had a certain resemblance to the smell of a charred pizza crust. Perhaps, this is a kind of reaction that underlies the leopard marks on a Neapolitan cornicione. Again, here I have completely ignored the roles of dough hydration, dough density, gluten networks that harbor water inside the dough, and air flow throughout the crust. Yet, it appears to me that the role of the simple sugars in dough might be of primary concern in formation of the charred bubbles. Have a great Labor Day weekend!