Breads of India.
A tandoor wall at 450 °C radiates heat several times as fiercely as an oven at 250 °C. A naan that needs five minutes at home cooks there in about one.
Most Indian breads are unleavened and cooked on a tava, the slightly concave iron griddle (XXVI.5). Roti or chapati is whole-wheat atta, water and a little salt, kneaded soft, rested, rolled thin and cooked on a dry hot tava, then held over the flame (phulka) until it balloons with steam. Paratha is the same dough rolled out, brushed with ghee, folded or coiled into layers — square, triangular or the spiral lachha paratha — rolled again and shallow-fried, so that the fat between the layers makes them flaky (XXV.6). Stuffed parathas enclose spiced potato, radish or paneer. Puri is a small round fried in hot oil until it puffs into a ball; bhatura its larger, slightly leavened cousin.
Naan comes from the tandoor, a clay oven heated by a charcoal or wood fire at its base until its walls reach 400–480 °C. The soft dough — flour, yogurt, a little yeast or baking powder, milk — is stretched into a teardrop and slapped against the inside wall, where it sticks; the wall cooks one side by contact while the opposite wall radiates on the other, and in a minute or two it is puffed, blistered and charred in spots, then pulled off with a hook. Radiant heat grows with the fourth power of absolute temperature (II.4), so the hotter wall delivers far more heat than a home oven. The workshop compares the heat.
Below: the radiant heat flux from a wall at the temperature you choose onto a bread surface at 100 °C (Stefan–Boltzmann law, exact for a black body), with convection added (teaching), and the time to cook a naan through (teaching energy of about 3 MJ per square metre, heated from both sides).
- Make roti and puff it.
- Layer a paratha.
- Explain the tandoor's heat.
- Cook naan at home.
Fourth power: the tandoor's secret
A tandoor wall at 450 °C delivers about 23.2 kW per square metre to the bread, an oven wall at 250 °C only 6.9 — about 3.4 times less — because radiation rises with the fourth power of the absolute temperature. In the teaching estimate a naan cooks in about 65 seconds in the tandoor and 3.6 minutes in a 250 °C oven: the right order, and the reason a home naan is paler and drier. The fastest way to come close at home is the hottest surface you have, near a strong grill.
Roti (8): mix 250 g atta with about 170 g warm water and a pinch of salt into a soft dough, knead 5 minutes, rest 30. Roll balls of 50 g into 15 cm rounds; cook on a hot dry tava until bubbles appear, turn, cook until spotted, then hold over a gas flame with tongs until it puffs; brush with ghee. Naan at home (6): mix 300 g flour, 1 tsp yeast, 1 tsp sugar, ½ tsp baking powder, 1 tsp salt, 100 g yogurt, 100 mL warm milk and 2 tbsp oil; knead soft, rise an hour; shape into teardrops, brush the top with water and press nigella seeds on; cook on a smoking-hot cast-iron pan, wet side down, until bubbled, then turn the pan over a gas flame or put it under the hottest grill until the top chars in spots; brush with butter.
Cook one naan in a 250 °C oven on a tray and another on a smoking-hot pan finished under the grill. Compare the time and the char.
Terms
- Tava
- A shallow iron griddle for roti and paratha.
- Phulka
- A roti puffed over an open flame.
- Paratha
- A layered, ghee-brushed, pan-fried flatbread.
- Tandoor
- A clay oven whose hot walls cook naan.
Sources
- A teaching value chosen for the course: the right order of magnitude and shape, not a measurement of a particular food.
- K. T. Achaya, Indian Food: A Historical Companion, Oxford University Press, 1994; and A Historical Dictionary of Indian Food, 1998.