Gingelly, Groundnut or Refined: Picking the Right Cooking Oil

A shelf of cooking oils can look interchangeable if you're just reading labels quickly, but gingelly oil, groundnut oil and a plain refined oil genuinely taste different, and Tamil cooking traditionally uses each for different purposes rather than treating them as one interchangeable "cooking oil."

Gingelly oil: the traditional pickling and tempering oil

Gingelly oil (cold-pressed sesame oil, sometimes called nallennai) has a strong, distinctive, slightly nutty flavour that comes through clearly in whatever it's used in — which is exactly why it's the traditional choice for pickling. Pickle and thokku recipes that call for oil almost always mean gingelly specifically, since its flavour is part of the finished condiment rather than a neutral cooking medium. It's also commonly used for tempering (thalippu) in traditional cooking, and for a few specific dishes — like certain versions of puliyodharai (tamarind rice) — where the gingelly flavour is considered essential to the dish rather than optional.

Groundnut oil: a milder, everyday cooking oil

Groundnut (peanut) oil has a milder flavour than gingelly, with just a faint nuttiness, and is traditionally used more broadly for everyday cooking — frying, sautéing vegetables, and general stovetop use where you want the oil to support the dish rather than dominate its flavour. It's a common choice specifically for deep-frying items like bajji and vada in households that prefer it to a plain refined oil, for the flavour it lends rather than for any other property.

Refined oil: the neutral, all-purpose choice

A plain refined vegetable oil (sunflower, or a blended "gold" refined oil) is essentially flavourless, which makes it the default choice when a recipe wants the oil to stay in the background — everyday sautéing, general frying, and any dish where you don't want the oil itself contributing a taste. It's the most commonly stocked, general-purpose option precisely because of that neutrality.

A quick matching guide

• Pickling, thokku, and traditional puliyodharai — gingelly oil, for the flavour it contributes.
• Everyday tempering, frying bajji or vada with a flavour preference — groundnut oil.
• General cooking where a neutral flavour is wanted — plain refined oil.
• Store all cooking oils in a cool, dark place, away from direct heat or sunlight, which can cause oil to turn rancid faster.

Why some dishes specify smoking point, not just flavour

Beyond flavour, oils also behave differently at high heat, which is part of why deep-frying and light sautéing sometimes call for different oils in the same kitchen. Refined oils generally tolerate higher, more sustained heat before they start to smoke, which is one reason they're a common choice for deep-frying bajji or vada in bulk, even in households that prefer groundnut oil's flavour for everyday cooking. Gingelly oil is used less for deep-frying and more for finishing or lower-heat tempering, where its stronger flavour is the point rather than a side effect of the cooking method.

All three are in the oil category, in a range of pack sizes from 500ml to 1 litre. If a recipe specifically calls for gingelly or groundnut oil by name, it's usually for the flavour, not interchangeably with whatever neutral oil happens to be in the kitchen. Express delivery in about 60 minutes if the pickling batch is ready to go and the gingelly oil bottle is empty.