Frying
Also called sautéing, shallow frying, stir-frying, deep frying
Quick answer
Cooking a spice in enough hot fat, for long enough, that the fat is a cooking medium rather than a carrier.
What it does to spices
Distinct from blooming, and the distinction is temperature and duration rather than equipment. Blooming is seconds in warm fat to dissolve aroma compounds into it; frying is minutes at a heat that browns, and it changes the spice rather than extracting from it. Whole spices fried in hot oil darken, swell and develop Maillard products that were not there before, which is why fried whole chillies taste nutty rather than merely hot. The failure mode is sharp and irreversible: sugars and pigments burn well below the temperature at which the spice itself is destroyed, so paprika, ground chilli and anything carrying dried fruit or peel scorch to bitterness in seconds while a whole cumin seed is still developing. The order of entry into the pan is therefore not a convenience — hard whole seeds first, then aromatics, then anything ground, then anything sweet.
What has been measured
Findings from studies and documented practice that concern this technique, each with the conditions it was made under and what it does not show.
Frying and blooming in fat · Depends on conditions Capsaicin, pungency
Chilli powder fried in oil for 10 min gave up its capsaicinoids to the oil to an extent that depended on temperature. The oil held 14.8 mg/kg after frying at 130 °C, 20.9 at 150 °C, 19.4 at 170 °C and 7.4 at 190 °C, which the authors calculate as 73.5, 103.9, 96.4 and 36.8 per cent of what the powder contained. At 130 °C the release was incomplete; at 190 °C only about a third was recovered, which the authors attribute to serious loss of capsaicinoids at that temperature.
Conditions: in oil or fat · 130, 150, 170 and 190 °C · 10 min · Chilli powder fried in four times its weight of oil; proton NMR
Hot oil does carry chilli heat efficiently, but not at any temperature: in this preparation oil that was too cool left heat behind in the powder, and oil at 190 °C returned little more than a third of it.
What this does not show: One chilli powder, one oil and a single frying time of 10 min; a tempering lasts seconds and a poured chilli oil cools as it meets the chilli. A recovery above 100 per cent shows the size of the measurement error.
Measured on the spice
Frying and blooming in fat · Depends on conditions Capsanthin, Capsanthin 5,6-epoxide, 13-Z carotenoid isomers, colour
Frying chilli powder in oil at 130 °C for 10 min transferred 97.0 per cent of its capsanthin and 93.2 per cent of its total carotenoids into the oil. At higher temperatures far less pigment survived: 37.1 per cent of the capsanthin at 150 °C, 23.1 at 170 °C and 14.9 at 190 °C. As the temperature rose, capsanthin 5,6-epoxide and 13-Z isomers increased, the red carotenoids were lost faster than the yellow, and browning products built up.
Conditions: in oil or fat · 130, 150, 170 and 190 °C · 10 min · Chilli powder fried in four times its weight of oil; proton NMR
The red of chilli moves into oil almost completely at a moderate frying temperature and is destroyed by a hot one. Pigment and pungency did not share an optimum in this study: the colour was best extracted at 130 °C, the heat at 150 to 170 °C.
What this does not show: One chilli powder and ten minutes of frying, much longer than a spice spends in a tempering. The study did not test temperatures below 130 °C, so it cannot say where extraction begins to fall off at the cool end.
Measured on the spice
Frying and blooming in fat · Converts Capsaicin, Vanillin
The vanillin content of chilli oil rose steadily with frying temperature from 130 to 190 °C. Vanillin is a known thermal breakdown product of capsaicin, and the authors take its rise as confirmation that higher temperature drives the degradation of capsaicin in the oil.
Conditions: in oil or fat · 130 to 190 °C · 10 min
What this does not show: Vanillin can form from other constituents of chilli as well, and the study did not trace it to capsaicin directly. The amounts are far too small to be assumed perceptible.
Measured on the spice
Frying and blooming in fat · Decreases Crocin, Tricrocin, Crocin-3, Crocetin, 13-cis-Crocetin, colour
Saffron heated in olive oil at 180 °C for 5 min lost about two thirds of its colour compounds: the total fell to 36 per cent of the uncooked level. Crocin dropped to 66 per cent and tricrocin to 26 per cent, while crocin-3 rose slightly and two compounds absent from raw saffron appeared, crocetin and its 13-cis isomer. The pattern is that of the sugars being split from the crocins, followed by partial isomerisation of the crocetin released.
Conditions: in oil or fat · 180 °C · 5 min · 0.08 g of Spanish saffron in 7.5 mL of olive oil
Saffron’s colour compounds are sugar esters that dissolve in water, and hot oil neither extracts them well nor spares them. The finding supports the usual practice of steeping saffron in liquid, and gives no support to frying it.
What this does not show: One saffron and one frying condition, hotter and longer than a spice usually spends in oil. Peak areas at a single wavelength, so breakdown products that do not absorb there are not counted.
Measured on the spice
Frying and blooming in fat · Decreases Diallyl disulfide, Monoterpenes, Methylpyrrole, Aldehydes from the heated oil, volatile oil
Garlic, Ginger, Sichuan pepper
What is smelled when spices hit hot oil is aroma leaving the pan. Stir-frying garlic released abundant diallyl disulfide into the air; stir-frying ginger and Sichuan pepper released abundant monoterpenes and related terpenoids; all of the spices tested gave off methylpyrrole, and the aldehydes emitted by the heated oil itself rose roughly tenfold once spices were added. A separate study of a test kitchen, in which 16 herbs and spices were shallow-fried in rapeseed oil and a chicken curry was cooked, found the same pattern by stage: aldehydes while the oil heated, monoterpenes while the spices fried.
Conditions: in oil or fat · Spices stir-fried in corn oil; emissions measured in the air by on-line mass spectrometry
Frying a spice in fat is not only an extraction into the oil. Part of the lightest aroma is driven off into the room in the same moment, which is one reason the time a spice spends in hot fat is kept short.
What this does not show: Both read in the abstract only, and both are air-quality studies: they measured what entered the air and not what stayed in the oil or the food, so the share lost cannot be stated. The first study names its Sichuan pepper as Zanthoxylum piperitum.
Measured on the spice
Frying and blooming in fat · Extracts Linalool, β-Myrcene, γ-Terpinene, Eucalyptol (1,8-cineole), Terpinen-4-ol, Linalyl acetate, Furfural, (E,E)-2,4-Heptadienal, volatile oil
In oil fried with Sichuan pepper, thirteen compounds were identified as the key contributors to aroma, and eleven of them came from the spice: terpenes and terpene alcohols including β-myrcene, γ-terpinene, eucalyptol, linalool, terpinen-4-ol and linalyl acetate, which carried the herbal, piney and citrus notes. Only two, (E,E)-2,4-heptadienal and furfural, were made in the frying, by oxidation of the oil and browning reactions; these carried the fatty and roasted notes.
Conditions: in oil or fat · Fried huajiao oil compared with raw and roasted Sichuan pepper and with heated rapeseed oil
A fried Sichuan pepper oil is chiefly the spice’s own aroma moved into fat, with a small roasted contribution from the heated oil. This is a different balance from chilli oil, where the pour makes much of the aroma.
What this does not show: Read in the abstract only, which gives no frying temperature or time. One oil and one preparation, and the tingling compounds were not part of the study.
Measured on the spice
Frying and blooming in fat · Depends on conditions 2-Methylpyrazine, (E)-2-Heptenal, 2-Methoxy-3-(1-methylethyl)pyrazine, volatile oil
Sichuan pepper, Star anise, Fennel seed, Bay leaf, Tsaoko, Ginger
In a rapeseed oil fried with a mixture of Sichuan peppercorn, chilli, ginger, green onion, star anise, fennel seed, tsaoko and bay leaf, the frying temperature strongly influenced which volatiles formed. Frying at 160 °C gave the most diverse set, spanning aldehydes, ketones, terpenes, esters and alcohols. Seventy-three compounds distinguished the oil fried at 150 °C from that fried at 160 °C but only thirty-nine separated 160 from 170 °C, which the authors read as high heat reducing complexity.
Conditions: in oil or fat · 150, 160 and 170 °C · 15 min at the temperature the authors selected · Rapeseed oil fried with a mixture of spices, chilli and green onion
What this does not show: Read in the abstract only. One formulation of ten ingredients fried together, so no change can be assigned to any single spice, and three temperatures only ten degrees apart.
Measured on the spice
Where it is used
The pairings that specifically call for this technique.
- Dried orange peel with sichuan pepper — The Sichuan pairing, and one where the chemistry is visible: Sichuan pepper carries limonene and the peel is largely limonene, so the two share a citrus register and reinforce each other rather than merely coexisting. In orange-peel beef the peel is fried until it darkens and the pepper follows, and the numbing and the bitterness together carry a dish that is otherwise sweet and hot.
- Black cardamom with dagad phool — The two smoky components of the Deccan masalas, and they arrive at the smoke by different routes: black cardamom is fire-dried and carries acquired smoke compounds, while dagad phool is a lichen whose earthiness reads as smoke without being any. Goda masala and the Chettinad mixtures use both, and a blend with one and not the other reads as thinner rather than as less smoky.
- Ají amarillo with chicken — Ají de gallina is the dish that defines the pairing: shredded poached chicken in a sauce of ají amarillo paste, bread, milk and nuts. The chilli supplies colour, body and a fruity warmth simultaneously, which is why the sauce needs no other seasoning to be recognisable.
- Daun salam with lemongrass — The two whole aromatics that go into an Indonesian pot together and stay there. Lemongrass supplies a citric lift that is identifiable in the finished dish; salam supplies a tea-like background that is not. Indonesian cooking layers whole aromatics deliberately and this is the base pair.
- Kashmiri chilli with turmeric — A colour partnership as much as a flavour one, and worth stating plainly because the colour is the point: Kashmiri chilli gives red and turmeric gives yellow, and the orange between them is the colour of most North Indian gravies. Both pigments are fat-soluble — capsanthin and curcumin — so both need blooming in oil rather than stirring into water, and both fade in light.
- Korarima with onion — Ethiopian cooking builds on an enormous quantity of onion cooked down dry before any fat is added, and berbere goes in against that base. The pairing is really about that method: korarima is aromatic enough to survive the long cooking that reduces the onion to sweetness, where more volatile spices would not.
- Fennel seed with fenugreek — Panch phoron is defined by its five seeds being used together and whole, so this is one of the few pairings where co-occurrence really is the claim. Fennel is sweet and anise-led, fenugreek bitter and maple-like, and the Bengali balance depends on the fenugreek being the smallest proportion of the five — it is the ingredient that ruins the mixture if measured by eye.
- Curry leaf with mustard seed — The defining pair of South Indian cooking, and the two ingredients of nearly every tadka: mustard seeds into hot oil until they pop, then curry leaves, which crackle and release their aroma in seconds. The order matters and the timing is short — this is a technique as much as a pairing, and it is the sound of a South Indian kitchen.
- Dried rose with turmeric — These coexist in Persian cooking rather than combine, and the distinction is the honest answer. Turmeric goes into the hot oil at the very start of a khoresh, where it loses its rawness and becomes a savoury base; rose is scattered at the end for aroma. They are in the same pot and never in the same moment, and a mixture that grinds them together to be used at one point tends to muddy both.
- Annatto with coriander seed — Annatto is used across the Caribbean and Latin America mainly for its colour — bixin, fat-soluble, bloomed in oil — and carries only a faint peppery earthiness of its own. Coriander seed supplies the aroma the dish would otherwise lack, which makes this a division of labour rather than a meeting of flavours.
- Galangal with ginger — Two rhizomes of the same family used together deliberately, which is the point worth making: Southeast Asian cooking treats them as different ingredients rather than as alternatives, and a paste containing both is not being redundant. Galangal is sharp, piney and almost medicinal; ginger is hot and sweet from gingerol. Substituting one for the other — the commonest assumption outside the region — removes a note rather than weakening one.
- Galangal with garlic — The foundation of every Indonesian and Malay spice paste: allium for savoury body, galangal for the resinous top note that identifies the region. Both are wet and both are ground raw and then fried, which is what turns a harsh paste into a sweet one — the pairing is as much about the technique as the ingredients.
- Galangal with onion — Indonesian shallots are the bulk of a spice paste and galangal is one of the aromatics they carry. The relationship is one of proportion — a great deal of shallot, a little galangal — and it is why the pastes taste sweet and deep rather than sharp: the allium is cooked down before anything else happens.
- Curry leaf with onion — Curry leaf goes into hot fat with shallot and gives its aroma up in seconds, and vadouvan is the preserved form of exactly that moment — the leaves are cooked with the alliums and dried alongside them, which keeps far more of the aroma than drying them separately does. Fresh leaves and fried shallot is one of the defining smells of South Indian cooking.
- Curry leaf with garlic — Both go into the same hot fat and both are aromatic rather than structural, which makes the timing the whole difficulty: garlic burns in about the time curry leaves need to crackle. South Indian practice adds the garlic first and the leaves last, in the final seconds, and a tempering with both is a small exercise in sequencing.
- Mustard seed with onion — Mustard seed popped in hot fat loses its pungency and turns nutty, and shallot cooked in the same fat turns sweet — two ingredients that both become milder and rounder through the same step. That is why they open so many South Indian dishes together and why vadouvan, which is that step preserved, contains both.
- Makrut lime leaf with onion — Asian shallot is the sweet bulk of a Thai paste and makrut is one of the aromatics it carries, which makes this the same base-and-aromatic relationship galangal and shallot have. The shallot is fried down until sweet; the makrut is what stops the result tasting merely of onion.
- Timur with potato — Boiled potato dressed with mustard oil, sesame, chilli and timur is one of the everyday Nepali achar dishes. Potato is a blank carrier, and the timur provides the lift that stops a cold dressed potato from tasting flat.
- Jimbu with lentils — Jimbu exists in the kitchen to finish dal. Fried in ghee and poured over black lentils, it gives the savoury allium depth that makes Thakali dal recognisable, and the dal would be flat without it in exactly the way an Indian dal is flat without its tadka.
- Jimbu with potato — Potato curries and simple fried potatoes in Nepal are often tempered with jimbu, whose onion-and-chive savour is a natural partner for potato in the way chives are in European cooking.
- Radhuni with lentils — Radhuni fried in mustard oil or ghee is a standard phoron for Bengali dals — masoor and moong especially — where its celery-and-parsley sharpness lifts a mild lentil without the heaviness of garlic.
- Radhuni with pumpkin — Bengali pumpkin and mixed-vegetable dishes are among those tempered with radhuni, where its sharp herbal note balances the pumpkin’s sweetness. The specific seed chosen varies by household; radhuni is one recognised choice rather than the rule.
- Curry leaf with kudampuli — The two defining aromatics of the Keralan fish curry: curry leaves fried in coconut oil at the start, kudampuli simmered through it. One brings aroma, the other acid and smoke, and the dish is recognisable from the pair.
- Jakhiya with potato — Jakhiya aloo — boiled potatoes tossed in mustard oil crackling with jakhiya and dried chilli — is the best-known Uttarakhandi dish built on the seed. The crunchy, nutty seeds give plain potato texture and a toasted flavour.
- Jakhiya with spinach — Greens in the Uttarakhand hills are commonly tempered with jakhiya; its toasty crunch contrasts with soft wilted leaves.
- Jakhiya with pumpkin — Pumpkin cooked in the hill style begins with a jakhiya tempering in mustard oil, which offsets the pumpkin’s sweetness with a nutty, faintly bitter note.
- Dawadawa with spinach — Efo riro, the Yoruba leaf stew, is defined by iru fried in palm oil with onion and pepper before the greens go in. Leaves are lean and grassy, and the fermented bean gives them the savoury backbone.
- Malvani masala with white fish — The coastal Malvani fish curry — masala, roasted coconut and kokum — and fish rubbed with masala and rice flour before frying are the core uses of the blend. Its pepper and chilli are pitched to stand up to fish and coconut.
- Persillade with potato — Pommes de terre sautées finished with persillade in the last seconds of cooking are a French standard; the hot fat softens the raw garlic just enough.
- Douchi with garlic — Douchi and garlic are chopped and fried together at the start of the dish in Cantonese cooking, for steamed spare ribs, for steamed fish and for the stir-fries sold in English as black bean sauce dishes. The fermented bean supplies salt and savouriness and the garlic the sharp top note.
- Douchi with tofu — Mapo tofu, the Sichuan dish of bean curd in a chilli and Sichuan pepper sauce, is commonly made with a spoonful of douchi fried in the oil beside the chilli bean paste. Tofu is bland and takes its seasoning from the sauce, and the fermented bean is one of the things that makes the sauce savoury.
Questions this page answers
- how to fry whole spices without burning them
- why do my spices burn in oil
- what order to add spices to hot oil
- frying spices in oil
- why does paprika go bitter in the pan