Seasoning Korean Namul with Olive Oil: A Practical Guide

Why Olive Oil in Namul?

Sesame oil occupies an almost irreplaceable role in the Korean kitchen. Blanched spinach, bellflower root, bean sprouts — a few drops at the end and the dish is complete. Over the past several years, however, attempts to work extra virgin olive oil into Korean cooking have become noticeably more common, both at home and in restaurants. According to consumption trend data from Korea's Korea Agro-Fisheries & Food Trade Corporation (aT), imports of extra virgin olive oil have grown steadily since 2018, with household use overtaking foodservice volumes.

The purpose of this guide is to examine whether that shift reflects a genuine culinary fit, not just a trend. Claiming that olive oil can fully replace sesame oil would be premature; so would dismissing it outright. What matters is a working set of criteria: which vegetables, at what stage of cooking, and in what quantity.

Sesame Oil and Olive Oil: What Sets Them Apart

The most obvious difference between the two is aroma. Sesame oil is dominated by the intense, roasted nuttiness of toasted sesame — even a small amount reshapes the character of an entire dish. Its smoke point sits at around 160 °C, which is why it is typically added at the very end rather than used as a cooking medium.

High-quality extra virgin olive oil (EVOO), by contrast, carries fresh, layered flavours — grass, almond, green apple. Its characteristic bitterness and peppery finish (pungency) are attributed to polyphenol compounds including oleocanthal. Research from Spain's Higher Council for Scientific Research (CSIC) has reported that higher oleocanthal content is associated with a more pronounced peppery aftertaste.

In terms of aroma intensity, olive oil is generally milder than sesame oil. That is both a limitation and an asset. In vegetable dishes where the goal is to let the ingredient speak for itself, olive oil's quieter flavour profile can actually be an advantage.

Which Namul Work Best — A Category-by-Category Guide

Grouping namul into three broad types provides a useful starting framework.

First, mild greens with a fresh, grassy character. Spinach, mallow, aster scaber, water parsley, and stir-fried zucchini fall into this group. Because the vegetable's own flavour is the centrepiece, the strong roasted note of sesame oil can sometimes mask it. Olive oil tends to sharpen the green freshness and natural sweetness of these vegetables instead. Blanching mallow and dressing it with only olive oil, salt, and garlic is an approach that sits close in spirit to the slow-cooked southern Italian vegetable tradition, even if the seasoning logic is arrived at from a completely different starting point.

Second, strong-scented mountain vegetables. Aralia shoots (두릅), fernbrake, wild sesame leaf, and shepherd's purse all have assertive, individual aromas that can clash with olive oil's bitterness. For this category, keeping sesame oil is a reasonable choice; if olive oil is used, pairing it with fermented condiments such as soy sauce or doenjang (fermented soybean paste) helps balance the overall flavour. A 1:1 blend of the two oils is also a workable middle ground.

Third, cooked vegetables (sukchae). Bean sprouts, mung bean sprouts, sweet potato stems, and braised eggplant belong here. Because these release significant moisture during cooking, too much oil of any kind makes the dish heavy and wet. Since olive oil is less viscous than sesame oil and spreads more quickly, starting at about 70–80% of your usual sesame oil quantity and adjusting upward is the recommended approach.

Timing Determines Flavour

Olive oil's aromatic compounds are sensitive to heat. Adding it during a stir-fry step drives off some of those volatile flavours, though it does help coat the vegetables and reduce moisture loss. Adding it after cooking, in the dressing stage, preserves as much of the oil's native aroma and polyphenols as possible.

For namul, the most effective method is to complete any stir-frying or blanching with water or a small amount of neutral oil, adjust the seasoning, and then drizzle extra virgin olive oil over the vegetables just before tossing. This is precisely the logic behind using olive oil as a finishing oil in Mediterranean cooking. Data reported by Italy's National Research Council (CNR) indicate that both temperature and heating time can affect bioactive compounds including oleocanthal, which supports the case for adding it at the end rather than during cooking.

Choosing the Right Olive Oil

For Korean vegetable dishes, a medium-intensity EVOO is generally the better fit. Early-harvest oils with pronounced bitterness and pungency can overwhelm mild vegetables like spinach or mallow. Softer, buttery or almond-forward styles tend to work more naturally alongside soy- and sesame-based seasonings.

By cultivar, Ojiblanca — with acidity around 0.16% and polyphenols above 600 mg/kg — is noted for a relatively balanced flavour profile that adapts well to Korean vegetable preparations. Sibarita, which also tends toward low acidity and a gentle flavour, is another option worth exploring. Whichever oil is chosen, keeping it away from light and air after opening is essential to maintaining the flavour it brings to the dish.

A Working Recipe: Spinach with Olive Oil

Blanch 200 g of spinach in salted boiling water for one minute, then refresh in cold water and squeeze out excess moisture. Season with half a teaspoon of minced garlic, one teaspoon of light soy sauce, and a pinch of salt. Drizzle one teaspoon (approximately 5 ml) of extra virgin olive oil over the spinach and toss gently. No sesame oil is needed — the oil's grassy notes support the spinach's natural sweetness. A scatter of toasted sesame seeds adds back a nutty note if that is preferred.

For more assertive namul like fernbrake or bellflower root, a 2:1 ratio of olive oil to sesame oil is a reasonable starting point. The two oils complement each other, and the result is more familiar than a full substitution while still shifting the flavour in a new direction.

Olive oil remains something of an outsider in Korean cooking, but approaching it as an ingredient to test against each vegetable — rather than a rule to follow — makes it possible to arrive at a set of criteria that genuinely works for the way you cook.