Week 12 Bake: The bread you cook on a surface

The last bench session — pita, naan, roti and tortilla off a dry hot surface, and the steam that lifts a bread with no yeast in it

10 May 2027

Eleven weeks of getting dough into an oven, and this one does without. A flatbread is cooked on a surface: heat conducted into one face at a time, at temperatures a domestic oven cannot reach, for times measured in seconds. The tin, the stone, the steam in a closed box, the hour of proving — today you find out how much of that apparatus was ever load-bearing.

Before the session#

Everyone makes pita and roti. Then pick one of naan or corn tortilla; between the two of you on a bench, do both and swap.

Mix the pita dough at home the day before. Per person: 300 g bakers’ flour, 180 g water, 6 g salt, 3 g instant yeast, 15 g olive oil — 60% hydration, 2% salt, 1% yeast, 5% oil. Ten minutes of mixing to a smooth dough, finish at 24 °C, bulk ninety minutes, then divide into six pieces of about 80 g and round them. Bring them covered on a floured tray. They will sit four hours at room temperature or overnight at 4 °C.

Buy atta for the roti. It is stone-milled wholemeal wheat, ground much finer than the wholemeal in a supermarket baking aisle and a great deal thirstier — it takes 65 to 70% water where a coarse wholemeal at the same figure stays gritty and tears when you roll it. If you are doing tortillas, buy masa harina, and check the bag says nixtamalizado. Cornflour and polenta are not substitutes; one is pure starch and the other is the wrong grind, and neither will hold together. For naan, full-fat plain yoghurt and ghee or a neutral oil.

Kit: a rolling pin, tongs, and a dry heavy pan — cast iron, carbon steel or a baking steel. Thin non-stick will lose fifty degrees the moment a cold disc lands on it, and there are no fifty degrees to spare this week.

Read the week 12 lecture first. The bench work is fast and mostly irreversible, and there is no time to work out what is happening while it happens.

In the session#

Three hours. Heat the surface first; everything else waits on it.

A baking steel in a 250 °C oven needs forty minutes. A cast-iron pan on the largest burner needs ten. Test it by flicking water across the face: the drops should skitter and disappear, not sit and simmer. Simmering means you are below about 200 °C and the pita will fail.

Pita. Roll one ball at a time. Work from the centre outwards, quarter-turn between passes, to 20 cm across and 3 mm thick, and run a finger over four points around the disc before you stop — an even thickness is the entire exercise. Onto the steel it goes bare, no oil, no tray.

Here is what happens next. Both faces of the disc reach 100 °C within about twenty seconds and set into thin skins while the middle is still cool, wet dough. Then the water in that middle boils. Steam occupies roughly 1600 times the volume of the water it came from, it is produced faster than it can escape through two set skins, and it forces them apart. Two to four minutes and the pita is a balloon that collapses into a pocket as it cools. In a pan rather than an oven, set the first face for thirty seconds, flip, and the lift comes on the second side.

Three ways it goes wrong, and you will see all three on the bench today. Rolled unevenly, the thin half sets first and the steam vents sideways through the half still soft: half a pocket and a dense lip. Rolled too thick, the centre never reaches 100 °C before the outside is cooked. On a cool surface the disc dries from the outside in and browns without ever inflating, and you have made a cracker. None of those three is a fault in the recipe.

Roti. 200 g atta, 130 g water, 4 g salt. No yeast, no starter, no baking powder, nothing. Knead five minutes and rest thirty, and the rest is not negotiable: the bran needs the time to take up water, and the gluten needs it to relax enough that a 2 mm disc stays 2 mm instead of springing back to 3. Divide into six, roll each to 16 cm.

Tawa dry and hot, around 230 °C. Thirty seconds on the first side until pale spots show, flip, forty seconds on the second while you press the edges with a folded cloth, then lift it with tongs straight onto the open flame. It balloons in three or four seconds. That is the pita mechanism again with nothing fermenting anywhere in the dough — steam is the only leavening this bread has ever had. Roll one at 4 mm as a control. It will brown, it will cook through, and it will lie flat, because there is too much dough between the faces for the middle to reach boiling before the skins are done.

Naan. On the bench: 300 g plain flour, 120 g full-fat yoghurt, 60 g water, 15 g ghee, 6 g salt, 5 g sugar, 3 g instant yeast. That is week 9’s argument in a flat shape — fat coats the gluten strands and shortens them, so the bread tears tender instead of chewing. The yoghurt brings acid as well as fat: near pH 4.5 it slackens the gluten, and its lactose and milk protein brown faster and darker than a lean dough would. Bulk ninety minutes, divide into five, roll into teardrops about 5 mm thick.

A tandoor runs at 400 to 480 °C. The naan is slapped onto the clay wall, sticks because its underside is wet, and comes off in sixty to ninety seconds blistered and charred in patches. We have no tandoor, so: pan as hot as it goes, brush one face of the naan with water, lay it wet-side down so it grips, lid on for a minute until the top is domed with bubbles, then turn the whole pan upside down over the burner and let the flame catch those bubbles for twenty seconds.

Tortilla. Corn first: 200 g masa harina, 260 g warm water, 3 g salt, mixed and rested ten minutes. Flatten a ball under your palm — if the edge cracks the dough is dry, and 10 g of water at a time will fix it. Press to 2 mm between two sheets of plastic. Comal at about 200 °C: fifty seconds, flip, forty seconds, flip again, and on that third turn it should puff.

Nothing in that dough is gluten and nothing ever was. What holds it together is nixtamalisation. The maize is simmered and then steeped in a calcium hydroxide solution at around pH 12, which dissolves the pericarp, partly gelatinises the starch and lets the wet grain grind into a cohesive masa. The same alkaline cook frees the grain’s niacin, which in untreated maize is bound up as niacytin and passes straight through you, and it lifts the calcium and the available amino acids as well. Maize crossed the Atlantic in the sixteenth century without the alkaline cook attached to it, and pellagra followed.

The flour tortilla makes the opposite case: 300 g plain flour, 50 g lard or shortening, 180 g warm water, 6 g salt. Rub the fat in, mix, rest thirty minutes, roll to 2 mm, forty seconds a side. This one has gluten, and the fat is there to keep it short. That is why a flour tortilla folds cold without cracking and a corn one, held up by gelatinised starch alone, snaps.

Afterwards#

Stack them in a clean tea towel as they come off the heat. The trapped steam keeps the skins pliable; a pita cooled naked on a rack goes rigid within the hour and will not open.

Worth a look back, because today undoes most of it. Week 1 built a gluten network and weeks 2 to 5 mainly argued about how much water to put in it. Week 6 swapped one yeast strain for a population. Week 7 took the gluten away entirely and left you holding a pentosan gel that only acid could protect. Week 8 boiled a gelatinised skin onto the outside, week 9 coated the strands in fat and egg, week 10 laminated butter between them, week 11 replaced the biology with a chemical reaction that starts the moment it gets wet. This morning’s roti has none of that — no culture, no yeast, no fat, no tin, no oven — and it still inflates. Structure comes from whatever is available. The only question worth asking of a dough is which thing is holding it up: gluten, pentosans, gelatinised starch, steam or a leavening salt. Answer that and the decisions about temperature, hydration and time mostly answer themselves.

Log the surface temperature, the seconds per side and whether each bread inflated. Then read bake-off 3: the showpiece, which is due on Friday 28 May, a fortnight after teaching ends. Twelve weeks of logs are the material you build it from.