Tony,
That's a good question but one that may be difficult to answer because of personal preferences. What I would be interested in knowing is what our members have been using in their cold fermented NY style doughs where the salt is above about 2%. I picked that number because it falls in line with the amount of salt often used in bread doughs. For example, see the King Arthur piece on salt at
http://www.kingarthurflour.com/professional/salt.html. Also, when I checked the dough recipes in Professor Calvel's book
The Taste of Bread, the predominant salt value for a basic, non-specialty French bread was 2%. There were a few recipes at 1.8% and one that was at 2.2-2.3%, but the latter amount was for a bread recipe (involving the intensive mixing method) that Prof. Calvel did not recommend.
As another frame of reference, one might consider the salt levels used in acrobatic doughs. For such doughs, the salt can get to close to 4%. One example, at 3.91% salt, is the dough recipe at the PMQ Think Tank Recipe bank at
http://www.pmq.com/Recipe-Bank/index.php/name/Acrobatic-Training-Dough/record/57732/. That is a recipe that Tony Gemignani apparently used at one time. Acrobatic doughs are not intended for consumption.
In terms of what our members have used for the NY style dough, you already noted the 2.5% salt level used by Glutenboy. At
http://www.pizzamaking.com/forum/index.php/topic,10714.msg95352.html#msg95352, you will see that LaPizzaBrutta used a NY style dough recipe with 3.42% salt. tdeane (Terry) says that he uses anywhere from 2.5-3%. A related point that you should keep in mind is that at high salt levels, the salt can slow down the fermentation process. As a result, if you are not careful with your timing, you can end up with an underfermented dough at the time you plan to use the dough. As you can see under the section "Osmotic Pressure" at
http://www.theartisan.net/dough_development.htm, salt exerts an inhibitory effect on yeast activity once it gets above 1.5%. Remember also that Glutenboy's dough can last for several days (e.g, up to about 8 days) and LaPizzaBrutta's dough was a 15-day old dough. So, salt's effect is not limited to its taste effect in the crust. It has many other effects.
Bob1 also raises an important point. In addition to looking at the salt at the dough level, you should also consider how much salt is used in the sauce and also the cheeses and toppings, especially meat toppings like pepperoni and sausage that contain high salt levels.
Please let us know what amount of salt you elect to use and with what results.
Peter
