Pickles & ferment bases
kimchi base
김치 양념 · A fermented paste of gochugaru, fish sauce or saeujeot, sweet rice flour paste, and aromatics that seasons napa cabbage or other vegetables for kimchi. It is the foundational paste from which all Korean kimchi preparations are built, functioning simultaneously as flavoring, brine, and lacto-fermentation medium. The base is mixed with salted, wilted cabbage (or other vegetables), packed, and left to ferment.
The formula
4:1:1 gochugaru : liquid umami : sweet rice flour paste by weight
Single batch (~200 g paste) seasons ~1 kg salted, drained napa cabbage (one standard baechu-kimchi head). Scale by vegetable weight. Example: 100 g coarse gochugaru + 25 ml fish sauce (or 20 g saeujeot) + 25 g sweet rice flour paste (cooked from 5 g flour + 25 ml water). Add 15–20 g garlic paste and 3–5 g grated ginger as aromatics.
Identity
- Gochugaru (coarse Korean chili flakes) provides color, spice, and capsaicin-bound flavor compounds unique to sun-dried, smoked Korean chilis
- Fish sauce or saeujeot supplies free amino acids (glutamate, IMP) for umami and sodium chloride for lacto fermentation selectivity
- Sweet rice flour paste creates a viscous carrier that adheres the paste to vegetable surfaces and feeds lactic acid bacteria with accessible sugars
- Garlic and ginger are non-negotiable aromatics — garlic contributes allicin and sulfur compounds; ginger provides gingerols and antimicrobial support
- Lacto-fermentation is the defining process: salt-tolerant LAB (Leuconostoc, Lactobacillus) dominate over spoilage organisms, producing lactic acid and lowering pH to ~3.5–4
Ingredients
| Base | Gochugaru (coarse Korean chili flakes) | Use coarse-ground (suncheon or similar) for texture and better adhesion. Fine-ground increases paste density and reduces the characteristic chewy texture. Suncheon is traditional for its slightly smoky, clean heat. |
| Liquid | Fish sauce (myeolchi aekjeot) or saeujeot (salted shrimp) | Fish sauce is most common in commercial and home baechu-kimchi. Sajeot (salted krill) is traditional in some coastal regions. Both provide sodium chloride, free amino acids, and moisture for the paste. |
| Binder | Sweet rice flour (chapssaltgaru) paste | Sweet rice flour whisked into boiling water (approximately 1:5 ratio) and cooked until translucent and smooth, 3–5 minutes. The amylopectin-rich starch gelatinizes at 65–69°C, creating a thick, adhesive paste that feeds LAB and holds the base together. |
| Aromatics | Garlic (minced to paste) | Approximately 15–20% of gochugaru weight by classical proportion. Allium sativum alliin + alliinase react on mincing to produce allicin compounds that mellow during fermentation. |
| Aromatics | Fresh ginger (grated) | Approximately 3–5% of gochugaru weight. Provides zingerone and shogaol; aids digestion and contributes antimicrobial properties that support controlled fermentation. |
| Seasoning | Fine sea salt (for vegetable salting, separate from base) | Not part of the paste itself, but the base is applied to salted vegetables. Salt concentration in the final vegetable (2–3% w/w) is critical for controlled lacto-fermentation. |
Method
- 1Cook the sweet rice flour paste: whisk sweet rice flour into cold water (1:4–5 ratio), bring to a boil over medium heat while stirring constantly until translucent and slightly thickened, 3–5 minutes. Cool completely to room temperature.Gelatinization of sweet rice starch (high amylopectin) creates a smooth, viscous paste that feeds LAB, improves adhesion to vegetable surfaces, and produces the characteristic sticky, chewy texture in finished kimchi. Uncooked flour risks uneven fermentation and a raw starch taste.
- 2Combine cooled rice paste with gochugaru in a large bowl. Add fish sauce (or diluted saeujeot brine) and mix thoroughly with a spoon or gloved hand until chili flakes are evenly saturated and the paste is uniformly thick without dry pockets.Fish sauce provides soluble umami compounds that penetrate the gochugaru particles and migrate into the vegetable during marinating. The viscosity of the rice paste should coat the chili flakes without making the mixture soupy.
- 3Fold in minced garlic and grated ginger. Mix until fully incorporated. The base should smell sharp, savory, and faintly sweet from the rice paste.Garlic allicin develops within minutes of mincing through the alliinase reaction; ginger's proteolytic and antimicrobial compounds integrate during mixing. These aromatics are essential to kimchi's character and must be evenly distributed throughout the paste.
- 4Taste the base. It should be intensely savory, moderately spicy, and slightly sweet. Adjust with a pinch more fish sauce for umami depth or a small amount of gochugaru for heat. Do not add liquid.The base is concentrated — it will mellow once applied to salted, watery cabbage. Correct seasoning of the paste ensures a balanced finished kimchi after dilution and fermentation.
- 5Use immediately to dress prepared, salted, and drained napa cabbage leaves or Korean radish. Pack tightly into an airtight or water-seal fermentation vessel to expel air. Ferment at room temperature for 24–72 hours before refrigeration.Salting and wilting the vegetable (typically 2–4 hours with coarse salt, then rinsing and draining) reduces internal water activity, allowing LAB in the base to dominate. Tight packing creates anaerobic conditions. Room temperature fermentation kick-starts LAB activity; refrigeration slows it for long, cold aging.
Techniques that matter
Lacto-fermentation
Salt-tolerant lactic acid bacteria (Leuconostoc mesenteroides, Lactobacillus plantarum) dominate over gram-negative spoilage bacteria when salt concentration (2–3%) and anaerobic conditions are controlled. They convert plant sugars to lactic acid, lowering pH from ~6 to ~3.5–4, which preserves the kimchi and develops sour, complex flavor over days to weeks.
Rice flour paste (starch gelatinization)
Sweet rice flour starch (high amylopectin, low amylose) gelatinizes at 65–69°C, producing a thick, adhesive paste that increases viscosity of the liquid phase, feeds LAB with accessible sugars, and gives finished kimchi its characteristic sticky, glossy texture.
Water activity control via salting
Applying 2–3% salt to the vegetable draws out water by osmosis, lowering water activity (aw) to ~0.95–0.97. This creates selective conditions where LAB thrive while spoilage bacteria and molds are inhibited.
Anaerobic fermentation
Packing kimchi tightly expels oxygen; LAB are facultative anaerobes that produce CO2 (visible as bubbles within hours to days). In sealed or water-seal vessels (onggi), this creates a CO2-rich, low-oxygen headspace that prevents aerobic mold and yeast growth on the surface.
Variations & derivatives
Baechu-kimchi base (napa cabbage)Nationwide Korea
The archetype. Applied to salted, halved or quartered napa cabbage. May include 2–3 inner cabbage leaves stuffed with extra paste. Most commonly made with myeolchi aekjeot (anchovy fish sauce).
Kaktugi base (radish kimchi)Korea
Same paste applied to salted, cubed Korean radish (mu). Typically more fish sauce relative to gochugaru for the denser root vegetable. Often includes chives (buchu) folded in.
Ggakdugi base (cubed radish, dry kimchi)Korea
A drier application — radish is salted, then paste is rubbed on rather than mixed with liquid. Ferments faster due to less brine accumulation.
Yangbaechu-kimchi (young radish leaf kimchi)Korea
Uses young radish leaves and tops instead of napa cabbage. The base is mixed with slightly less gochugaru to accommodate the more delicate leaf texture.
Bokkeum-kimchi base (stir-fry kimchi)Korea
Made slightly thicker with more rice paste and less liquid. Intended for kimchi jjigae and bokkeumbap, where the base melts into the broth rather than adhering to a vegetable surface.
Saewoo-kimchi base (shrimp kimchi)Korea
Replaces fish sauce with saeujeot (salted fermented shrimp) or kimbul, giving a more overtly marine, funky character. Common in coastal provinces.
Used in these dishes
Substitutions
- Fish sauce (myeolchi aekjeot) → Saeujeot (salted fermented shrimp) or vegan fish sauce — Saeujeot gives a more marine, umami-dense result; reduce quantity by ~20–30% as it is saltier and more intensely flavored. Vegan fish sauce (soy sauce + seaweed) works for plant-based versions but fermentation character and depth differ noticeably.changes result
- Sweet rice flour (chapssaltgaru) → Wheat flour, cornstarch, or tapioca starch — Wheat flour produces a gummier texture; cornstarch and tapioca lack the slight chew that sweet rice flour provides. Sweet rice flour is the classical choice for good reason. Arrowroot is acceptable for gluten-free preparations but may produce a slightly different texture.changes result
- Gochugaru (Korean chili flakes) → Aleppo pepper + paprika blend or cayenne + smoked paprika — Neither replicates the specific capsaicin-bound flavor compounds, sun-drying character, or颗粒 size of gochugaru. The result will taste Western rather than authentically Korean. Use only in genuine necessity; the base will lack characteristic depth and color.changes result
Troubleshooting
Base is too thin or soupy and slides off the cabbage
Too much liquid from fish sauce or insufficient rice paste. Rice paste may not have been cooked long enough to fully gelatinize. → Cook rice flour paste until visibly translucent and coating a spoon. If too thin, add a small amount of additional cooked sweet rice flour paste. Reduce fish sauce quantity or use saeujeot, which is denser.
Kimchi ferments too quickly — turns sour within 24 hours, mushy texture
Fermentation temperature too warm (above 24°C / 75°F); excessive salt draw-out creating too much brine; too much residual sugar from rice paste. → Ferment at 16–20°C (60–68°F) for the first 24–48 hours. Ensure cabbage is well-drained after salting and rinsing. Reduce rice flour paste quantity slightly for warmer climates.
Soft, mushy cabbage instead of crunchy
Over-salting or over-wilting the cabbage before applying base; excessive brine accumulation during fermentation; fermentation temperature too warm for too long. → Salt cabbage for 2–4 hours maximum, rinse briefly, and drain thoroughly. The cabbage should remain firm and slightly pliable, not limp. Refrigerate as soon as desired sourness is reached.
Base tastes harsh with raw garlic flavor dominating, lacks depth
Garlic not properly minced to a fine paste; insufficient fermentation time; rice paste not cooked enough to gelatinize and neutralize raw starch flavor. → Mince garlic to a fine paste using a mortar, grater, or food processor. Ensure rice paste is fully cooked (boiled until translucent, not just warmed). Allow fermentation to proceed at least 2 days at room temperature before tasting.