Vol. XV · Dry Heat Plate 9 of 11deep-frying, batter, breading, tempura, double frying, chips, oil temperature, draining, karaage, 炸HT

Deep-Frying at Home.

Chips fried once are either pale and limp or brown and hollow. Fried twice — once to cook, once to crisp — they are both crisp and fluffy.

Each fried food has its temperature. Delicate things with a thin coating — tempura, fish — fry hot and fast, 170–180 °C, so the coating crisps before the inside overcooks. Thick or raw-centred things — chicken pieces, whole potatoes — fry cooler, 150–165 °C, or in two stages, so the inside cooks before the outside darkens. A thermometer clipped to the pot is the most useful frying tool (IX.7).

Coatings do two jobs: they shield the food from the oil, so it steams gently inside its shell, and they become the crust. A dusting of flour or starch (Japanese karaage, Chinese 干炸) gives a thin, crisp crust; a batter of flour and liquid (tempura, fish and chips) gives a puffy one, crisper with cold liquid, little mixing and some starch or baking powder; a breading of flour, egg and crumbs (schnitzel, tonkatsu) gives a crunchy shell. And the double fry — a first, cooler fry to cook through, a rest, a second hot fry to crisp — is the secret of chips, Korean fried chicken and many Chinese dishes (复炸). The workshop compares single and double frying for chips.

Below: chips (10 mm) fried once at the temperature and time you choose, against the classic double fry, 150 °C for 6 minutes, a 20-minute rest and 190 °C for 2.5 minutes (thermal bench): crust depth, browning and water lost.

What you will learn
Workshop
Thermal bench: potato, 10 mm slab, from 20 °C. Crust: depth of the layer dried above 100 °C. Browning on the course teaching scale; water lost as a share of weight. Typical oil temperatures from common practice: tempura and fish 170–180 °C, chicken 160–170 °C, chips 150 °C then 185–190 °C.

Cook it, rest it, crisp it

In this model a single fry at 175 °C for 7 minutes gives a crust of about 3.2 mm and browning of 0.57; the double fry gives a crust of 2.6 mm and browning of 0.67. The real advantage of the double fry is control: the first, cooler stage cooks the inside to a fluffy, gelatinised mash (VII.1) without colour; the rest lets steam escape and the surface dry and firm; the short, hot second stage crisps and browns the shell without overcooking what is inside. Chips can be blanched in the first stage hours ahead and finished just before serving.

Practical frying. Dry the food; coat it just before frying; lower it in gently, away from you; fry in batches no more than a tenth of the oil's weight (IX.7); keep the temperature in range; lift out when the bubbling slows and the colour is right; drain on a rack (paper under food traps steam and softens it); season while hot; serve at once. For tempura, mix ice-cold water into flour with a few strokes of chopsticks — lumps are fine — and fry within minutes.

At the stove

Make two small batches of chips from the same potato: one fried once at 175 °C until golden, one fried at 150 °C for 6 minutes, rested 20 minutes, then fried at 190 °C for 2 minutes. Taste after five minutes: the double-fried batch stays crisp longer.

Heston Blumenthal's triple-cooked chip of the 1990s — simmered, fried at 130 °C, then at 190 °C — refines a much older habit: in Belgium frites have long been fried twice.

Terms

Batter
A liquid coating of flour and water or other liquid.
Breading
A coating of flour, egg and crumbs.
Double frying
A cooler fry to cook through, then a hot fry to crisp.
Karaage
Japanese fried chicken dusted in starch.
Match oil temperature to the food, the coating to the crust wanted, and double-fry thick foods: cook through cooler, crisp hotter. Drain on a rack.

Sources

  1. A teaching value chosen for the course: the right order of magnitude and shape, not a measurement of a particular food.
  2. H. McGee, On Food and Cooking: The Science and Lore of the Kitchen, 2nd ed., Scribner, 2004.