Recognizing the Symptom
On the outside, everything looks done: the rim is browned, ideally even with leoparding, and the cheese has melted and taken on color. Inside, something is off.
- When you cut into it, the crumb feels wet, glassy, or sticky instead of light and airy. The dough tends to string rather than break cleanly when cut.
- Press test: pressing a fork or finger into the crust, it gives way without springing back, or feels wet/clammy.
- Bottom check: lifting the pizza, the underside is often noticeably pale or unevenly browned, even though the topping already looks done.
Gum line: Often a thin, dense, slightly glassy layer is visible right under the topping (sometimes called a “gum line”) – a zone that got neither oven spring nor browning. This shows up as raw dough under toppings, distinct from the browned surface above it.
Causes
Oven, Stone, or Steel Not Sufficiently Preheated
A baking stone or steel takes considerably longer to heat all the way through than the air inside the oven. The oven’s “preheat done” indicator only reflects air temperature – the stone or steel’s mass often lags far behind. If that thermal mass isn’t at target temperature when the pizza goes in, exactly the bottom heat that bakes the crust through is missing, while the topping and rim already take on color from the top heat.
Wrong Rack Position
If the pizza sits too high in the oven, top heat dominates: the topping and rim brown quickly, but the base gets too little direct heat from below and stays raw. Baking on a sufficiently preheated stone or steel that stores enough heat is usually not a problem here. It becomes an issue mainly when baking instead on an unpreheated sheet pan – then heat from below is missing entirely.
Dough Stretched Too Thick
The thicker the base, the more mass has to bake through in the short baking time. At the very short bake times of high baking temperatures (60–90 seconds at 450–500 °C / 840–930 °F), there simply isn’t enough time to bake the middle through, even though the surface already looks done.
Topping Too Heavy or Too Wet
A lot of topping, very wet sauce, or mozzarella that wasn’t drained bind part of the baking heat: energy first goes into heating and evaporating the moisture in the topping instead of into the dough underneath – so overall less heat reaches the base, and it bakes through less well. In the most extreme case, with a very wet, heavy topping and a very short bake time at the same time, there isn’t even enough heat to evaporate the moisture meaningfully – the dough stays completely raw under the topping while the rim around it still browns.
Dough Too Cold (Straight From the Fridge)
If a cold dough ball is shaped and baked straight from the fridge without coming up to room temperature first, it cools the stone or steel down more when it goes in and itself needs longer to bake through – while the surface already takes on color from the oven heat.
Wrong Stretching Technique (Rolling Pin Instead of Hands)
Rolling the dough out with a rolling pin instead of shaping it with your fingers from the center to the rim completely presses out the fermentation gas held in the dough. This makes the dough denser and more compact than with the Neapolitan hand technique, which makes even baking through harder still. That’s exactly why the Neapolitan technique explicitly calls for shaping the base with fingers only, not rolling it out with a pin.
Hydration Too High for the Chosen Baking Temperature
At very hot, short bakes (e.g. 450–500 °C / 840–930 °F, 60–90 seconds), the water in the dough barely has time to evaporate. If hydration is clearly higher than what matches the baking temperature, the outside chars before the excess water inside has been able to evaporate – the result: dark/browned outside, raw or doughy inside. This typically affects cases where too-high hydration is used for very high, short baking temperatures – under these baking conditions the dough tolerates noticeably less water than at lower temperatures with a longer bake time (e.g. 280–350 °C / 535–660 °F, 8–12 minutes).
Found your cause but still unsure what to do?
Solution: Step by Step
Preheat for at least 30 minutes, better 45–60 minutes, at maximum oven temperature – not just until the oven’s “ready” indicator goes off, since that reflects air temperature, not the thermal mass of the stone or steel. If you have one, check the surface temperature with an infrared thermometer.
Place a well-preheated stone or steel higher up in the oven, and an unpreheated sheet pan lower down instead – that way, in both cases, enough heat reaches the base before the topping burns on top.
When shaping, aim for a base thickness that matches your baking temperature and oven type, and isn’t too thick – the shorter the bake time, the thinner the base should be.
Drain mozzarella well before topping, don’t use tomato sauce that’s too runny, and keep the overall amount of topping moderate.
Let it come up to temperature briefly before baking, instead of shaping and baking it straight from the cold.
If hydration doesn’t match the baking temperature, either lower the hydration or lower the baking temperature and extend the bake time accordingly. The gives you concrete values for your flour.
Distinction From “Over-Proofing” and “Chewy/Tough”
Over-proofing describes a dough that has lost its structure over a long time through enzymatic breakdown: it collapses, browns poorly, and is wet/sticky throughout – the cause lies in how the dough was handled before baking. Chewy or tough dough concerns a dough that is correctly and fully baked, but whose crumb stays tough to chew – a texture issue that shows up after a successful bake. Raw, undercooked dough despite a pizza that looks done is different from both: here the pizza looks done on the outside (browned, possibly with leoparding), but the base is actually still raw or wet inside – the cause lies mainly in heat transfer during baking (preheating, rack position, dough thickness, topping) and in hydration that doesn’t match the baking temperature, not in the fermentation beforehand.
