Shaping without degassing

Short answer

The gas that inflates the rim in the oven is already in the dough ball, so shaping should move it to the edge rather than squeeze it out. Press the centre flat with your fingertips, leave a border alone, and stretch by hand; save the rolling pin for styles meant to be thin and even.

Why the rim depends on shaping

During fermentation the dough fills with small gas bubbles. In a hot oven those bubbles expand and the water in the dough turns to steam, which is what makes the rim (the cornicione, in Neapolitan terms) puff. If the gas is pressed out during shaping, there is much less to expand, and the rim bakes flat and dense regardless of how good the dough was.

Shaping is therefore not just about getting a round of the right size. For styles with a raised edge, it is about deciding where the gas goes: out of the centre, which should be thin, and into a border that is left alone.

Opening a ball by hand

Start with the ball on a floured surface, smooth side down if you want that side to be the top. Press the centre with the flat of your fingertips, working outwards in a spiral or with a few firm presses, and stop short of the edge so a border of roughly a finger's width or two is never pressed. That untouched ring is the future rim.

Once the centre is flattened, lift and stretch: drape the dough over the backs of your hands or knuckles and let gravity do part of the work, rotating as you go, or stretch it on the bench while one hand anchors the middle. Stretch the centre, not the border. Turning the dough frequently keeps it even and helps avoid a thin spot that tears.

Temperature, relaxation and tearing

Dough straight from the fridge is firmer and less extensible, so it tends to resist, spring back and tear instead of stretching. Most cold-fermented balls handle better after time at room temperature — how long depends on the ball and the kitchen, but often an hour or more. Dough that keeps shrinking back is usually under-rested rather than faulty: cover it and give it ten or fifteen minutes before trying again.

Tearing during stretching often points to a thin spot from uneven pressure, dough that is still cold, dough that is under- or over-fermented, or a flour too weak for the stretch being asked of it. A small hole can usually be pinched closed; repeated tearing is worth diagnosing rather than forcing.

When a rolling pin is the right tool

A rolling pin flattens the whole dough evenly, rim included, and presses out most of the gas. That is a fault for a Neapolitan or New York pizza, but it is the intended result for styles that want a thin, even, cracker-like or flat-edged base, such as Chicago tavern style or St Louis. Some pan styles are pressed into the pan by hand instead, and are not stretched in the usual sense at all.

If you do use a pin for a style that should have a rim, roll only the centre and leave the edge unrolled, and accept that the result will be a little less airy than hand stretching.

Common misconceptions

“Professional pizza is shaped by tossing, so tossing is what makes the rim.”

Tossing is one way to stretch dough and can be useful, but the rim depends on leaving the border unpressed. Plenty of excellent pizza is opened entirely on the bench.

“Rolling pins are always wrong for pizza.”

They are wrong for rim-led styles and right for thin, even, cracker-style bases such as tavern style and St Louis.

“If dough tears, it needs more kneading.”

Cold dough, insufficient rest, uneven stretching and fermentation timing are more common causes than under-kneading.

What this page cannot tell you

Shaping cannot rescue a dough that is badly under- or over-fermented, nor create a rim in an oven that is not hot enough to inflate one. The border width and rest times given here are rough guides, not measurements.

Related

Evidence

• Modernist Pizza — The Cooking Lab
• The Pizza Bible — Ten Speed Press
• The Pizza Lab (column) — Serious Eats