Ok so if Marco recommends 1-5% vs with respect to water then what would that translate to vs weight of flour? Thanks.
I wouldn't get hung up on that number. The reason why Marco recommended 1-5% starter with respect to the weight of water is because that is the way things are done in Naples. When they make the dough in Naples, they start with the water and then select the amounts of the other ingredients, including the starter (or commercial yeast, if used), with respect to the amount of water. In the U.S., we measure everything in a dough recipe, other than the flour, as a percent of the weight of the flour, not the water. Once you decide on which recipe to use, you can convert the 1-5% starter to a percent of the flour.
To give you a simple example, if you look at Craig's dough recipe at http://www.pizzamaking.com/forum/index.php/topic,20477.msg202047.html#msg202047
, he uses the Ischia culture at 1.3% of the formula flour (the U.S. method). With 1300 grams of flour, the amount of Ischia culture he uses is 16.9 grams (1.3% of 1300 grams). The water in Craig's recipe comes to 62.5% of 1300 grams, or 812.5 grams. At 16.9 grams, the percent of the Ischia culture with respect to the formula water is 16.9/812.5 = 2.08%. So, his Ischia culture as a percent of the formula water falls within Marco's range.