Cold sauces & condiments
Zhenjiang xiangcu (Chinkiang black vinegar)
镇江香醋 · A traditional Chinese black vinegar from Zhenjiang, Jiangsu, brewed from glutinous rice with wheat bran and a solid-state qu starter through sequential saccharification, alcoholic fermentation, and acetic acid fermentation, then aged. Recognized as a geographical-indication product with a minimum aging requirement of 180 days and a minimum total acidity of 4.5 g/100 mL.
The formula
100:20:6 glutinous rice : wheat bran : qu starter (by mass), +1% salt
Reference commercial recipe per source [1]: 5000 g glutinous rice, 6000 g water, 1000 g wheat bran, 300 g qu, 50 g salt. Standards (QB/T series, source [2]) govern saccharification, alcoholic fermentation, acetic fermentation, aging, blending, clarification and sterilization.
Identity
- GI-tagged black vinegar from Zhenjiang, Jiangsu; aged ≥180 days
- Total acidity ≥4.5 g/100 mL
- Solid-state fermentation using wheat bran as the acetic-acid culture bed
- Made primarily from glutinous rice (糯米), not brown rice or generic rice
- Distinctive deep brown-black color from slow Maillard-driven aging, often adjusted with caramel (糖色)
- Flavor profile: layered sweet-sour with maltol, umami and gentle smokiness — not sharp like distilled white vinegar
Ingredients
| Base | Glutinous rice (糯米) | Starch source; steamed and cooled before inoculation. Per source [1] 5000 g base batch. |
| Base | Wheat bran (麦麸) | Provides surface area and nutrients for Acetobacter acetic culture bed during solid-state acetic fermentation; ~20% of rice mass. |
| Culture | Qu starter (酒曲/大曲) — contains Saccharomyces cerevisiae and molds | Performs saccharification and alcoholic fermentation; ~6% of rice mass per source [1]. |
| Liquid | Water | Used for soaking rice, steaming, and dilution at the acetic-fermentation stage; ~120% of rice mass. |
| Seasoning | Sea salt | ~1% of rice mass; controls spoilage flora and shapes final flavor per source [1]. |
| Flavor | Caramel (糖色) for color adjustment | Optional; used at blending to lock in the standard deep mahogany appearance. |
Method
- 1Soak glutinous rice, steam to fully gelatinized sticky rice, cool to ~28–32 °C.Hydrates and gelatinizes starch so the qu can saccharify it efficiently.
- 2Mix cooled rice with wheat bran and crushed qu starter; perform alcoholic fermentation in two stages (前发酵 then 后发酵) under anaerobic/semi-anaerobic conditions, leaving a central well for limited oxygen ingress.Qu saccharifies starch to glucose; Saccharomyces cerevisiae converts sugars to ethanol; wheat bran textures the mash for later solid-state acetification.
- 3Open the ferment, stir periodically, and run acetic fermentation (醋酸发酵) with daily turning so Acetobacter (including A. pasteurianus) on the bran surface oxidizes ethanol to acetic acid.Repeated aeration renews oxygen for the aerobic acetic bacteria and distributes heat and microbes evenly.
- 4Add salt once the mash smells sharply acidic and ethanol is largely consumed; transfer to closed vessels for 醋醅陈酿 (peck aging) — solid-state aging at minimum 180 days.Salt selects for desired flora and slows further metabolism; long solid-state aging develops maltols, esters, amino acids, and dark color.
- 5Press/filter aged pek to extract mature vinegar; blend, clarify (澄清), pasteurize (灭菌), adjust to standard acidity with water, and dose caramel color if needed.Blending normalizes batch-to-batch acidity and color; pasteurization stabilizes the finished liquid.
- 6Bottle and (per current draft QB/T standard) optionally continue post-bottling aging.Further rounds flavor and locks in the sensory profile characteristic of Zhenjiang xiangcu.
Techniques that matter
Solid-state acetic fermentation (醋醅固态发酵)
The wheat bran acts as a carrier for the acetic-acid pellicle; this surface-culture method is the defining feature of Zhenjiang vinegar and gives it maltier, rounder notes than submerged-fermentation black vinegars.
Periodic turning/stirring (翻醅)
Refreshes oxygen for Acetobacter and prevents overheating/anaerobic pockets.
Long solid-state aging (醋醅陈酿 ≥180 days)
Drives Maillard reactions and ester formation that produce the characteristic aroma and dark color.
Variations & derivatives
Traditional solid-state (手工固态)Heritage Zhenjiang breweries
Multi-year aging, sun- and shade cycles; deepest malt complexity.
Modern hybrid processLarger commercial producers
Per draft QB/T standard (source [2]): controlled stainless stages + accelerated aging; consistent acidity ≥4.5 g/100 mL.
Shanxi aged vinegar (老陈醋) comparatorShanxi province
Uses sorghum and large-quan process; smokier and sharper; not a substitution because of different grain base.
Sichuan Baoning vinegar (保宁醋)Sichuan
Uses wheat, peas, rice etc. with herbal additives — medicinal-leaning, medicinally spiced.
Used in these dishes
Substitutions
- Zhenjiang xiangcu → Rice vinegar + dark soy sauce + pinch of sugar — Approximates color and sweet-tart edge but loses malt depth and umami.changes result
- Zhenjiang xiangcu → Japanese komezu (米酢) — Both rice-based but Japanese komezu is sharper, paler, and lacks Maillard-aged depth.changes result
- Zhenjiang xiangcu → Shanxi mature vinegar — Both are aged Chinese black vinegars, but Shanxi is sorghum-based, smokier, and more pungent.changes result
- Zhenjiang xiangcu → Balsamic vinegar of Modena — Similar color and viscosity, but balsamic is grape-based with fig/date sweetness; only an emergency pantry swap.changes result
Troubleshooting
Vinegar tastes thin or one-dimensionally sharp
Insufficient solid-state aging or weak Maillard development; mash too wet. → Extend 醋醅陈酿 past the 180-day minimum, reduce turning frequency, and ensure proper surface-to-moisture ratio.
Surface film or pink/white mold during acetic fermentation
Contamination from inadequate salt timing or wild microflora; low acidity before salting. → Add the prescribed salt (≈1% of rice mass) earlier once alcohol is depleted; sanitize tools; maintain proper mash aeration.
Final color too light / amber rather than mahogany
Insufficient Maillard browning and missing caramel step. → Extend aging or dose 糖色 (caramel) at the blending stage per the modern standard.
Sourness flattens palate in finished dish
Standard Zhenjiang xiangcu is more acidic (≥4.5 g/100 mL) than many cooks expect; using it 1:1 in recipes that assume milder vinegar overpowers the dish. → Use the Zhenjiang vinegar as a seasoning accent rather than bulk acid; balance with sugar, soy, or sesame oil.