I wondered at the time whether the NYC slice joints used fresh mozzarella cheese. scott r said yes (that was back in 2006). What scott r said was confirmed by JasonZA.
The coal places (aka 'elite') all use fior di latte (fresh mozz), with one or two offering the option of fresh or aged. Joe's offers a fresh option, but the aged slices outsell the fresh ones by a factor of about 100 to 1. Coal is associated with fresh, while slices are associated with aged. Fresh mozz really doesn't work well on a typical 4-7 minute NY style slice because the longer baking time tends to be hard on it and it curdles. Best uses fresh with a 4 minute bake, and they use a fior di latte with seemingly good stability, but, imo, it could be considerably better with an aged Grande or a Grande clone.
Paulo, steel has no place in a broilerless oven. It speeds up the rate at which the bottom of the pizza bakes. This is great when you can match this breakneck speed on the top with the use of a broiler, but, without the broiler, you're going to have incredibly pale tops and charred bottoms. Both Best and Joe's have plenty of top color- color which you're not presently getting.
1/4" plate will do nothing to resolve this heat imbalance. A gas oven without a broiler in the main compartment is, by far, the hardest configuration to get great NY style pizza out of. I haven't timed a Joe's pie recently, although I'm pretty sure it's less than 7 minutes. I have timed Best's, though, and they're at 4. I promise you that you will never achieve a balanced 4 minute bake with steel in an oven without a broiler- and, believe me, you want to hit that Best bake time.
Because of your exposure to this forum, you're in a unique position to produce a pizza that's better
than Joe's and Best. Best is a flavor-deprived same day ferment, but with a fast bake that produces a great puffy texture, while Joe's has a slightly longer bake time and somewhat careless doughmaking techniques, both of which rob the dough from treasured oven spring, but, at the same time, Joe's produces pretty good flavor with their longer ferment.
Both of these outfits are dropping the ball somewhere. If you want a world class NY slice, your goal should be to piece together the best of both worlds- Best's oven thermodynamics (a 4 minute bake), Joe's multi day ferment along with your own conscientious approach to proper fermentation and gluten development.
Matching Best's 4 minute bake, though- a balanced
4 minute bake with good color on the top and not too much char underneath, matching that with your oven isn't going to be easy. A lot of people have tried and failed. At a minimum, you want a lower conductivity hearth material such as fibrament or unglazed quarry tiles. That won't get you to 4 minutes, but it should get you to a balanced 7 minute bake at your oven's peak temp. To hit 4, you want to do something like this:http://www.pizzamaking.com/forum/index.php/topic,21503.msg217026.html#msg217026
Re; your flour choice. Fermentation produces gluten. The longer the fermentation, the greater the gluten development (to a point). Very high gluten (13.5%+) flours can produce tender crumbs with same day ferments, but... fermentation produces flavor, so same day ferments tend to be flavorless. If you want flavor AND less propensity for toughness, you want multi day ferments with a slightly lower protein flour. For NY, 12.7-13.2% is ideal. Harinas Elizondo seems like a quality miller- they should have something 13ish. That's what you should be using.
Re; sauce. For the style of pizza you're making, imported Italian tomatoes are a waste of time. They just don't have the intensity of flavor to stand up to extended bake times. Mexico is renowned for their tomatoes. You should be able to track down a local tomato that puts Italian tomatoes to shame. Get a can of every brand of local tomato that your wholesaler carries and taste test each until you find the best. The goal should be a crushed tomato that's sweet yet tart, thick/not watery and robustly flavored.