The Right Oil for the Job
Smoke points, flavour and when to use what
A kitchen stocked with a single cooking oil is a kitchen with one tool for every job. Different oils have different smoke points, different flavour profiles and different appropriate uses. Using the right oil is not fussiness — it is the difference between a dish that tastes right and one that doesn't.
The domestic kitchen typically contains one bottle of olive oil and perhaps a spray of some neutral cooking oil. This is enough to get by — but it is not enough to cook well, because different fats and oils have meaningfully different properties: smoke points, flavour profiles, thermal stability and appropriate uses.
Understanding the basics of cooking oils removes a significant source of unnoticed failure from the kitchen. Oil chosen wrongly for the application can produce bitterness, off-flavours, or simply fail to perform the function it was selected for.
The smoke point
The smoke point is the temperature at which a fat begins to visibly smoke, indicating that it has begun to break down and produce acrolein — a bitter, acrid compound that contributes off-flavours to the finished dish. Cooking above the smoke point consistently is a reliable source of unidentified bitterness.
Smoke points are not fixed — they vary with the quality and freshness of the oil, its storage conditions and the presence of particles (such as the milk solids in unrefined butter, which burn readily). The figures below are approximate.
**Extra virgin olive oil**: approximately 180–200°C. Despite the widespread claim that it cannot be used for cooking, EVOO is perfectly adequate for most pan-frying and roasting below 200°C. Its polyphenol content provides some stability against oxidation. Use it for sautéeing, roasting vegetables and low-heat cooking.
**Refined olive oil / light olive oil**: 220–240°C. The refining process removes the volatile compounds that lower the smoke point, making it more heat-stable and far more neutral in flavour.
**Groundnut (peanut) oil**: 230–240°C. High smoke point, clean flavour. The traditional oil for deep-frying in many Asian cuisines and for stir-fries requiring very high heat.
**Rapeseed oil (canola)**: 200–230°C. The most common neutral cooking oil in British cooking. High in monounsaturated fat, mild in flavour, affordable and adequate for almost all cooking needs.
**Sunflower oil**: 220–230°C. Very neutral, high smoke point. Good for deep-frying. The flavour is clean but entirely uninteresting — appropriate when oil flavour should be invisible.
**Sesame oil (toasted)**: 170°C. This is not a cooking oil — it is a condiment. Its intensely nutty, roasted flavour degrades rapidly above 170°C. It should be added at the end of cooking, as a flavouring, not used as the primary cooking fat.
**Butter (clarified)**: 250°C. Clarifying butter removes the milk solids, eliminating the main source of burning. Ghee (Indian clarified butter) can be used for high-heat cooking without the browning limitation of regular butter.
**Butter (unclarified)**: approximately 150°C. The milk solids begin to brown around 120°C (useful for noisette butter) and burn around 150°C. For high-heat searing with butter flavour: combine with a neutral oil.
**Coconut oil**: 175–200°C (refined). Approximately 90% saturated fat, which makes it very stable. The unrefined version has a pronounced coconut flavour.
When flavour matters
Oil choice matters most in preparations where the oil is prominent in the finished dish: salad dressings, drizzling over finished plates, dipping bread, quick sautés where the oil is not fully integrated.
Extra virgin olive oil — particularly a good single-estate oil — has genuine flavour: fruity, peppery, herbal. Using it on a finished grilled fish or a dressed salad contributes something worth having. Using it in a batter or a cake where it will be surrounded by other flavours is a waste of the premium.
For dishes where the oil is a purely functional medium — deep-frying, stir-frying, any high-heat application — use a neutral oil with a high smoke point. The flavour of the oil will not survive into the finished dish in any meaningful way, so paying for quality olive oil is pointless.
The practical minimums
A kitchen needs at minimum two oils: a neutral, high-smoke-point oil for cooking (rapeseed or groundnut), and a good extra virgin olive oil for dressings, finishing and low-heat cooking.
A third addition worth considering: toasted sesame oil for finishing East Asian preparations; it is irreplaceable.
Everything else is a refinement on these basics.
Rancidity
All oils oxidise over time and exposure to heat, light and air. Rancid oil has a stale, crayon-like smell and a bitter, unpleasant flavour that contaminates whatever it is used in. This is a more common source of off-flavour in home cooking than is usually acknowledged.
Buy oils in quantities you will use within 3–6 months. Store in cool, dark conditions. Smell the oil before using it. The nose does not lie.