Kimchi gets its red color from gochugaru, a type of Korean chili flake made from sun-dried and crushed Korean red peppers. These pepper flakes are mixed into the seasoning paste that coats the cabbage and vegetables, staining everything a vivid red-orange during the salting and fermentation process. Without gochugaru, kimchi isn’t red at all.
Gochugaru: The Source of the Color
Gochugaru is not the same thing as the generic chili powder or red pepper flakes you’d find in a Western grocery store. It’s made exclusively from Korean chili peppers that are sun-dried and then crushed into coarse flakes or a fine powder. The key difference in processing is that the seeds are meticulously removed before grinding. This creates a bright, uniform red color without the white or yellow specks that show up in regular red pepper flakes where seeds are left in.
Removing the seeds also eliminates bitter flavors, which is why gochugaru tastes noticeably different from standard chili flakes. It has a complex, slightly sweet, and smoky flavor with mild to moderate heat. When this vivid red powder gets mixed with garlic, ginger, fish sauce, and other seasonings to form the kimchi paste, it saturates the cabbage and radish with deep color that only intensifies as everything melds together.
The Pigment Behind the Red
The actual molecule responsible for the red color is capsanthin, a carotenoid pigment found in high concentrations in red chili peppers. Capsanthin is the dominant pigment in red peppers, making up roughly 46% of the total carotenoid content. It belongs to the same family of compounds that makes tomatoes red and carrots orange, but capsanthin produces a particularly deep, striking red.
A related compound called capsorubin also contributes, though in smaller amounts. Both capsanthin and capsorubin are powerful antioxidants, which is part of why red peppers (and by extension, kimchi made with them) carry some nutritional value beyond just flavor and color. The accumulation of capsanthin during ripening is the main reason chili peppers turn red on the plant in the first place. When those ripe peppers are dried and ground into gochugaru, the pigment carries through into everything the flakes touch.
Why Some Kimchi Isn’t Red
Not all kimchi is red. Baek-kimchi, which translates literally to “white kimchi,” skips gochugaru entirely. Instead of chili flakes, it’s seasoned with ingredients like Korean pear, garlic, ginger, chestnuts, jujubes, and pine nuts. The result is a pale, almost translucent fermented cabbage with a mild, clean flavor. This proves the point clearly: the cabbage, garlic, ginger, and fermentation process contribute zero red color on their own. Every bit of that red comes from the pepper flakes.
There are also varieties of kimchi made with less gochugaru that appear lighter orange rather than deep red, and some regional styles that use different ratios of ingredients. The intensity of the red depends on how much gochugaru goes into the paste and how finely it’s ground. A coarser flake tends to create a speckled look, while finely ground gochugaru produces a more uniform, saturated coating.
How Chili Peppers Became Part of Kimchi
Kimchi existed long before it was red. Chili peppers originated in the Americas and were introduced to Korea by Portuguese traders, via Japan, in the late 16th century. Before that, kimchi was closer to what we’d now call white kimchi, fermented with salt, garlic, and other aromatics but no chili heat or red color. The adoption of chili peppers transformed the dish into the version most people recognize today. It’s a relatively recent addition in the context of kimchi’s long history as a staple of Korean cuisine.
What Affects Color Intensity
If you’ve noticed that some batches of kimchi are brighter red than others, several factors play a role. The quality and freshness of the gochugaru matters most. Freshly ground flakes from recently dried peppers will be noticeably more vibrant than older gochugaru that has been sitting in a pantry for months, since the carotenoid pigments gradually break down with exposure to light and air.
The ratio of gochugaru to other paste ingredients also shifts the color. Recipes heavier on garlic, rice flour paste, or fish sauce relative to the chili flakes will look lighter. Some cooks add a small amount of sweet rice flour porridge to the paste, which dilutes the red slightly but helps the seasoning cling to the cabbage leaves more evenly. Over time during fermentation, the color can mellow somewhat as the acidity rises and the ingredients continue to break down, which is why very old, deeply fermented kimchi sometimes appears more brownish-red compared to a freshly made batch.