Fermented Kohlrabi: The Unexpected Crunch in Chili Condiments
Fermented kohlrabi is an ingredient that can surprise anyone encountering it in a jar of Chinese chili oil or chili crisp for the first time. It isn't a chile, an allium, or a seasoning, yet it can make a substantial contribution to a condiment's flavor and texture.
The ingredient is particularly associated with Lao Gan Ma's Hot Chili Sauce, sometimes described in English as chili oil with peanuts, beancurd, and kohlrabi. The product's ingredient declaration identifies kohlrabi as fermented, while the finished condiment contains small pieces that contribute a distinctly different texture from the peanuts and fried soybean curd.
What Is Kohlrabi?
True kohlrabi is Brassica oleracea var. gongylodes, a member of the same species that includes cabbage, broccoli, kale, cauliflower, and Brussels sprouts.
Unlike cabbage, which forms a head, kohlrabi develops a swollen stem above ground. The vegetable is crisp, mildly sweet, and somewhat reminiscent of a cross between a broccoli stem and a turnip.
The name literally means “cabbage turnip” in German.
When fresh, kohlrabi is quite mild. Fermentation and preservation transform it into something much more intensely savory.
Fermented Kohlrabi in Chinese Condiments
There is an important terminology issue here.
Chinese preserved-vegetable terminology doesn't always translate neatly into English. Ingredients appearing on imported products may be translated as kohlrabi, preserved vegetable, turnip, radish, mustard vegetable, or dried vegetable, depending upon the original Chinese term and the translator.
For example, 大头菜 (dà tóu cài) can be rendered as “kohlrabi” in some product translations, while culinary terminology can use the same or similar names for other members of the cabbage/mustard family.
Consequently, “kohlrabi” on an English ingredient label should not automatically be interpreted as proof that the producer used the fresh Western vegetable sold under that name.
What Does Fermented Kohlrabi Taste Like?
Fermentation gives the vegetable a much more assertive personality.
Depending upon the process, it can contribute:
- Salty savoriness
- Mild acidity
- Earthiness
- Vegetal sweetness
- Fermented complexity
- A chewy or crisp texture
Unlike fried garlic or fried shallots, which provide a brittle crunch, preserved vegetable can provide a chewy-crisp contrast.
That distinction is particularly noticeable in chili oils containing large quantities of peanuts or fried soybean curd.
Its Role in Chili Crisp
Fermented kohlrabi is primarily a texture and savory-flavor ingredient.
It can perform several jobs simultaneously:
Texture: It provides a firm, chewy bite that survives processing better than many fresh vegetables.
Salt: Preservation often contributes substantial salinity.
Umami: Fermentation produces compounds that deepen savory flavor.
Vegetal character: It introduces a cabbage-like or root-vegetable note that prevents the condiment from tasting entirely like fried ingredients and oil.
Contrast: Its texture breaks up the monotony of brittle fried particles.
This last function is especially important.
A condiment composed entirely of oil, fried garlic, chile flakes, and nuts can be rich and crunchy, but the mouthfeel may become monotonous. A preserved vegetable adds another kind of bite.
Fermented Kohlrabi vs. Fresh Kohlrabi
The difference is dramatic.
Fresh kohlrabi is watery, crisp, mild, and refreshing. Fermented or preserved kohlrabi is concentrated, salty, savory, and much more intense.
The preservation process removes or reduces some of the fresh vegetable character while concentrating flavor and altering texture.
In an oil-based condiment, that concentrated character allows a relatively small amount to make an obvious contribution.
Fermentation and Flavor Development
Fermentation changes vegetables through the activity of microorganisms and the chemical reactions that occur during preservation.
Depending on the method, carbohydrates can be converted into acids and other compounds, while proteins and other components contribute additional flavor precursors.
The result is not simply “sour cabbage.” Traditional vegetable preservation can create a broad spectrum of salty, savory, fermented, and aromatic characteristics.
This is one reason preserved vegetables are so useful in Chinese cooking: they function as seasonings as much as vegetables.
Fermented Kohlrabi in Lao Gan Ma-Style Chili Oil
The Lao Gan Ma Hot Chili Sauce formulation provides a particularly good illustration.
Its combination of chile, peanuts, fried soybean curd, and fermented kohlrabi creates three very different textural experiences:
- Chile provides the pepper component.
- Peanuts provide hard, nutty crunch.
- Fried soybean curd provides brittle, fried chew/crunch.
- Kohlrabi provides a more vegetable-like, chewy texture.
That combination is much more texturally complicated than a conventional chili oil.
Our tasting notes on this style of Lao Gan Ma describe the kohlrabi as providing a contrasting chewy cabbage texture and vegetal flavor, while the fried soybean curd contributes additional crunch.
As Reviewers What Do We Look For?
When reviewing a chili condiment containing fermented kohlrabi, we consider:
- Texture: Is it crisp, chewy, leathery, or soft?
- Size: Are the pieces large enough to notice?
- Saltiness: Does the preserved vegetable make the condiment excessively salty?
- Fermentation: Is there an interesting savory depth, or simply a salty vegetable taste?
- Balance: Does the vegetable complement the chile and oil?
- Freshness: Does it retain some pleasant vegetable character?
A good product should make the kohlrabi feel intentional rather than like an odd inclusion.
The Bottom Line
Fermented kohlrabi demonstrates that chili crisp is not merely a mixture of chile and fried aromatics. Preserved vegetables can play an important role in creating texture, salt, savoriness, and complexity.
For the enthusiast, it is one of the more intriguing ingredients to encounter on a label—and one worth seeking out if you enjoy chili condiments with varied textures.