Try this at your next meal. Pinch your nose shut, put a spoonful of something you like in your mouth, and chew. Then let go. The moment air moves again, the flavour arrives.  

Most of us assume flavour happens on the tongue. It mostly doesn't. The tongue registers five things: sweet, sour, salty, bitter and umami. Useful for staying alive, but a short list. Everything else you think you are tasting, the roastiness of coffee, the difference between a strawberry and a raspberry, is being read by your nose. 

When you chew, volatile organic compounds in food vaporise and travel up through the back of your throat into your nasal passage. Scientists call this retronasal olfaction, and when physical food rests on your tongue, your brain effortlessly blends these scent signals with basic taste impressions, creating what we call flavour. Without an intact sense of smell, an onion and an apple taste remarkably similar, both registering merely as crisp, moist, and mildly sweet. Aroma is what gives food its soul. 

The nose gets there first 

The first job of your nose happens before food even touches your mouth at all. Walk past a bakery and your mouth waters. That is not a figure of speech. It is the cephalic phase response, a set of reflexes triggered by the thought, sight and smell of food. Saliva rises, the stomach starts secreting acid, the pancreas releases a little insulin, all before the first bite. 

This is why restaurants and senior care homes pay attention to whether kitchen smells actually reach the people meant to eat. Among older adults especially, a dulled sense of smell is one of the more reliable warning signs for poor appetite and weight loss. Plenty of people learned the same thing during COVID. When smell went, the desire to eat went with it. 

What this means in the kitchen 

Roasted sesame oil is the workhorse of this category. It is rarely used for frying, and a teaspoon stirred into noodles or spooned over steamed fish does more than any amount of it added early. Raw sesame smells of very little. Almost everything we recognise as sesame comes out of the roast, which drives the Maillard reaction (a heat triggered process that creates browned, toasty, complex flavours)  behind compounds like 2-furfurylthiol which provides the core roasted sesame aroma.  

Chinese sesame millers worked this out long before anyone named the molecules. Coaxing fragrance from sesame seed demands exact precision. Under-roasting leaves the seed raw and bland, while over-roasting scorches it and introduces bitterness.  

Closing that gap is roughly what Arawana, the consumer brand of Wilmar's subsidiary Yihai Kerry Arawana, set out to do with its Finely Ground Sesame Oil. Its roaster gently heats each seed at a controlled temperature for longer, bringing the entire batch to its aromatic peak together rather than leaving a mix of raw and scorched seeds. The mill then grinds them finely without the friction heat that causes fragrance to dissipate. Seven parts roasting and three parts grinding is the rule of thumb, and only the first run of oil is bottled. 

All of which is worth remembering the next time you are deciding how to enhance your cooking. The tongue will register the salt and the sweetness either way. Nearly everything else is a decision about smell.