Perilla cultivation for seed oil is a Korean and Northeastern Chinese tradition; perilla oil is particularly associated with Gangwon province highland cuisine where the cool climate favours perilla seed cultivation
Deul-gireum (들기름, perilla oil) is pressed from the seeds of Perilla frutescens (Korean perilla, 들깨 — not to be confused with shiso) and represents one of the most distinctive cooking fats in Korean cuisine — rich in omega-3 alpha-linolenic acid, with an intensely nutty, somewhat assertive flavour markedly different from sesame oil. Perilla oil is used both as a cooking fat (for stir-frying leafy vegetables) and as a finishing flavour (added to namul at the end). Its flavour is more robust and assertive than sesame oil and is particularly valued in Gangwon province highland cuisine where perilla seed cultivation is traditional.
Perilla oil's assertive, nutty-slightly-pungent character makes it the flavour that defines Gangwon mountain cuisine's character — where Seoul cooking finishes with sesame oil, the highlands finish with deul-gireum, and the difference is immediately recognisable.
{"Perilla oil burns at a lower smoke point than sesame oil — use at low to medium heat; high heat produces bitter, acrid off-flavours from the omega-3 fatty acid oxidation","As a finishing oil: add after cooking is complete, never to the heat — the volatile aroma compounds that define perilla oil's character are destroyed by extended heat","For namul: perilla oil + salt is the traditional Gangwon province seasoning for mountain greens (산나물), providing flavour where sesame oil would be considered too 'city'","Use fresh — perilla oil oxidises rapidly; once opened, use within 3 months and store refrigerated; oxidised perilla oil produces unpleasant fishy-rancid notes"}
Small-batch stone-milled perilla oil from Gangwon producers has a depth and complexity that commercially extracted perilla oil cannot match. The traditional stone milling process preserves more volatile aroma compounds than mechanical pressing under heat. Perilla oil with guk-ganjang over blanched mountain greens (취나물, Aster scaber namul) is the quintessential Gangwon province flavor pairing.
{"Substituting sesame oil — the two oils are not interchangeable; perilla oil has a different fatty acid profile and a more assertive, pungent character; recipes that specify perilla oil produce different results with sesame","Storing at room temperature after opening — the high omega-3 content oxidises rapidly at room temperature; refrigeration after opening is essential"}