Pizza base burnt but toppings undercooked

What you're seeing

You pull the pizza out on time and the top looks half-finished — cheese glossy but not melted into the sauce, pepperoni still flat, no colour on the rim. Flip it and the underside is dark brown going on black, with bitter, scorched patches where it sat flattest. The cornicione is the giveaway: pale on top, scorched underneath, on the same piece of dough. Nor is it a timing accident — it happens on the first pizza and on the fourth.

The short answer

Your oven floor and your oven roof are cooking at different speeds, and the floor is winning. Move the slab up towards the roof, bring the grill element into the bake so the top gets radiant heat to match, and if your dough carries sugar or oil, take it out. You are balancing two heat sources, not lowering one.

Why it happens

A pizza is cooked by two different mechanisms at once

The base cooks by conduction — direct contact with a hot slab, quick and relentless. The toppings cook by radiation and hot air from above, far gentler. A wood-fired oven balances the two because the dome is genuinely as hot as the floor; a 60–90 second Neapolitan bake at 430–480 °C (800–900 °F) works precisely because both sides are extreme.

A domestic oven is not balanced. If your steel sits at 320 °C (610 °F) because it has been soaking above the bottom element while the roof radiates at the set 250 °C (480 °F), the underside finishes in roughly half the time the top needs. Neither number is wrong on its own — the ratio between them is the problem.

The slab is in the wrong place

The bottom rack is the worst position in most home ovens. It sits in the path of the lower element, so the slab takes radiant heat from below all through the preheat and keeps overshooting the air temperature. Meanwhile the pizza is as far as possible from the roof, where the useful top heat lives.

Move the same slab to the upper-middle rack — 15–20 cm from the roof — and two things change at once. The floor stops being blasted from underneath and settles closer to the set temperature, and the toppings sit close enough for radiant heat to do something. The grill element for the last two minutes then pushes the top past the base rather than the other way round. A baking steel is especially prone to this, because the high conductivity that fixes a soggy base will burn one if you park it on the oven floor.

Sugar and oil brown long before starch does

Plain dough browns through the Maillard reaction and starch dextrinisation, which need a surface well above 150 °C (300 °F) and take time. Sugar caramelises faster and lower, and malted flours behave the same way because their enzymes release extra simple sugars.

That is why a New York or pan dough carries 1–2% sugar and a little oil: it buys colour in a cool home oven. Put the same dough on a 350 °C (660 °F) floor and the sugars burn bitter before the cheese melts. A true Neapolitan formula — flour, water, salt, yeast and nothing else, on a soft 00 flour — is built for a very hot floor and a very short bake, and the Neapolitan settings carry no sugar at all. Match the formula to the surface temperature.

Bench flour on the underside

A heavy dusting of plain flour burns almost instantly on a hot slab and tastes acrid even when the dough beneath it is fine. Coarse semolina tolerates far more heat, and you need much less of it.

Fix it now

1. Move the slab up. Upper-middle rack, 15–20 cm below the roof, and preheat there a full 45–60 minutes so it stabilises in its new position.
2. Measure the floor before you launch. Point an infrared thermometer at the centre of the slab — at a dark, seasoned patch, never bright metal. Polished steel reflects infrared instead of emitting it, so a gun fixed at 0.95 emissivity can read tens of degrees low, telling you the floor is safe when it is the thing burning your base. Matte cordierite reads honestly. For a dough with sugar or oil you want 250–290 °C (480–555 °F); for a lean Neapolitan dough you can run as hot as the oven will give you.
3. Bring in the top heat. Grill element for the last 90 seconds to 2 minutes, watching continuously. A combined grill-and-fan setting is better still — moving air spreads the radiant heat across the pizza.
4. Cut a hot floor down between pizzas. Oven off for 5 minutes with the door shut, or move the pizza to the rack above the slab for the second half of the bake.
5. Drop the sugar and the oil for tonight. A hot floor wants a lean dough; if it is already mixed, bake on a tray on the rack rather than the slab and finish under the grill.
6. Switch to semolina under the pizza, and brush the slab between bakes. Burnt flour is a real share of the bitterness people blame on the dough.
7. Bake something forgiving while you dial it in. A marinara has no cheese to wait for, so a fast base is no problem.

Prevent it next time

• Keep the slab upper-middle and leave it there. Bottom-rack baking is the single most common cause of a burnt underside in a domestic oven.
• Own a surface temperature reading. Oven dials describe air. The number that decides your base is the one on the slab, and it can be 60 °C from what the display claims.
• Match dough formula to floor temperature. Sugar and oil below 290 °C (555 °F); lean dough above it. This is one decision, made when you mix.
• Use the grill as part of the bake, not as a rescue. Planning the last 90 seconds under the element gives an even pizza; reaching for it after the base has burnt gives a burnt pizza with melted cheese.
• Learn the underside check. Lift the edge with a peel at halfway. If the base is dark at 90 seconds, move it up a rack rather than hoping the top catches up.
• Watch for the opposite failure too. Overcorrect and you end up with a pale, floppy base — the target is both surfaces finishing together, not a cool floor.