Sweet Rice Wine (Jiuniang): The Measured Science, the Real History, and How to Make It Safely

Jiuniang (酒酿), also called laozao (醪糟), looks like a dessert and behaves like a brewery. Glutinous rice, a fistful of grey-white starter crumbled over it, two days in a warm cupboard — and you get something sweet, faintly alcoholic, faintly floral, that Chinese kitchens turn into breakfast, into a restorative broth, into the poaching liquid for the little rice balls known as 圆子 or 汤圆.

It is also one of the most casually mis-documented foods online. So this guide sticks to what has actually been measured: what the starter contains, what the alcohol content really is, the temperatures that separate success from a bin liner, and how long it keeps.

What 酒曲 actually is

Jiuqu is not a single organism and it is not yeast. It is a solid-state, spontaneously fermented starter grown on rice or wheat: a stable mixed culture of moulds, yeasts and bacteria. High-throughput sequencing of eight Chinese sweet-rice-wine starters found ten fungal and eleven bacterial genera, with Rhizopus, Aspergillus, Saccharomyces and Mucor dominant among fungi, and Weissella, Pediococcus and Lactobacillus dominant among bacteria. Bacteria in Chinese starters are frequently led by Bacillus.

That is the key contrast with Japanese koji: industrial koji-making favours a single monoculture species, Aspergillus oryzae. Qu — and its Korean and Japanese relatives nuruk and koji’s folk ancestors — are mixed cultures. The moulds do the saccharifying: metaproteomic work on baijiu jiuqu identified Rhizopus as secreting the most abundant glucoamylase. In plain terms, the mould eats the starch and makes sugar, and the yeast eats the sugar and makes alcohol. Both jobs happen in the same jar at the same time, which is why the flavour lands somewhere between syrup and wine.

Deep history, with the caveats

• c. 7000–6600 BCE — Jiahu, Henan. Residues in sixteen pottery vessels show a mixed fermented drink of rice, honey and hawthorn fruit or grape. Published in Nature in December 2004; it remains the earliest direct chemical evidence of a fermented beverage anywhere.
• c. 3400–2900 BCE — Mijiaya, Shaanxi. Two pits with pots, funnels and stoves; starch and phytolith residues of broomcorn millet, barley, Job’s tears and tubers, plus calcium oxalate (“beerstone”). Published in PNAS on 23 May 2016.
• c. 533–544 CE — 《齐民要术》. Jia Sixie’s treatise is the first comprehensive summary of qu-making, recording nine qu methods and more than forty brewing methods. Eight of the nine qu use wheat. Documented dosages: 神曲 at 2.5–5.5% of grain weight, 笨曲 at 14.3–16.6%.
• A caveat on the classic quote. The line “若作酒醴，尔惟曲蘖” (to make wine and sweet liquor, you need qu and nie) is usually cited to 《尚书·说命》 — but the transmitted chapters of that text are judged to be a later forgery. Treat the date of this line as unverified even though the term is genuinely ancient.

The chemistry, with real numbers

Glutinous rice is used because its starch is essentially all amylopectin — measured at roughly 98–100% of dry weight, with one study putting it at 99.70%. Amylopectin is highly branched and highly accessible to the mould’s enzymes, which is why the mash liquefies into syrup instead of staying grainy.

On alcohol content, here is what has actually been measured, because the internet will happily tell you anything from “non-alcoholic” to “as strong as wine”:

• A 2025 laboratory run at 30°C reached 33 °Brix total sugar, 0.34 g/100 g total acid, and 3.5% alcohol by volume at 43 hours, with Rhizopus delemar and R. microsporus dominant.
• An optimised run using 1.0% sweet jiuqu at 30°C for 48 hours produced 1.83% vol.
• A 2018 review gives a range for Chinese sweet rice wine of 0.5–14% vol.
• The draft national food-safety standard for 酒酿(醪糟), circulated for comment in January 2020, sets alcohol at ≤6.0% vol, solids ≥30%, and total acid ≤10 g/kg — and requires products above 0.5% vol to carry the warning “过量食用有害健康”.

So: home-made jiuniang typically sits in the low single digits of ABV, and it is not a non-alcoholic food. That matters for children, for pregnancy, and for anyone who assumes “sweet” means “safe.”

Making it: the parameters that decide success

• Oil-free and raw-water-free, end to end. Every vessel, spoon and your hands. Sanitise with boiling water or food-grade alcohol. This is the single most common cause of failure.
• Cool the steamed rice to about 30°C before pitching. Above roughly 40°C you kill the culture; below 25°C nothing starts.
• Ferment at 25–30°C. Above 35°C you favour contaminants over the culture you want.
• Read the surface. White mycelium is normal Rhizopus. Grey, black or green spots mean contamination — discard the whole batch. Do not scrape and keep.
• Stop it with cold. Refrigerate at 0–4°C when it tastes right. Fermentation slows but does not stop, so the jar will keep drifting drier and boozier.
• Timing guidance: acceptable jiuniang at 36 hours at a steady 30°C; amino acids peak around 72 hours with no further gain; do not push past 96 hours.

On keeping it: a Hunan enterprise standard filed with the provincial health commission gives 15 days at ambient and 30 days at 0–4°C for unpasteurised sweet rice wine, and 12 months for pasteurised product. If you made it at home, assume the shorter end.

Four regional styles worth knowing

• 东柳醪糟 (Dazhu, Sichuan). Glutinous rice with amylopectin ≥98%; the starter is made with 108 herbs. Eaten with rice balls or eggs, and canned for export.
• 孝感米酒 (Hubei). Long-grain glutinous rice from Zhuhu plus a local honeycomb-shaped starter; two styles, clear broth (清汤) and thick (糊汤). The canonical pairing is hot-dry noodles with thick rice wine.
• 黄桂稠酒 (Shaanxi). Glutinous rice from Qindu with osmanthus; fermented around 30°C for three days, and notably light at 0.5–1.5% vol. Served hot or cold.
• 客家娘酒 (Guangdong). A glutinous-rice huangjiu that is pressed and then 火炙 — the sealed jar is slow-heated over straw fire, which sterilises and caramelises it. It is the base of 鸡子酒, the confinement-period chicken dish.

The industry behind a home-scale food

• Dazhu County markets itself as “China’s laozao capital”: 200,000 mu of glutinous rice, 100,000 tonnes of grain, a full-chain output of ¥7 billion in 2024, with 8 leading processors and over 200 operators.
• Xiaogan reports 36 producers, over 200,000 tonnes of rice wine annually, and full-chain output of ¥6 billion in 2024, up 27.6% year on year.
• Heritage status exists, but at provincial level: 东柳醪糟 brewing technique on Dazhou’s first municipal list (2006-09-11) and Sichuan’s provincial list (2007); 孝感米酒 on Hubei’s fourth provincial list (2013); 客家娘酒 techniques on Guangdong’s third (2009) and fifth (2013) provincial lists.
• Geographical indications: 东柳醪糟 national GI protection (2011); 朱湖糯米 (2009); 孝感米酒 is Hubei’s first GI certification mark and appears in the China–EU GI agreement.

If you are buying it ready-made

• Read the ingredient list. Proper jiuniang contains glutinous rice, water and jiuqu. Sugar, thickener or “flavouring” means you are buying a dessert built to imitate it.
• Look for the alcohol figure. The draft national standard caps 酒酿 at 6.0% vol and requires solids of at least 30%. Products above 0.5% vol are supposed to carry the “过量食用有害健康” warning. If a label gives no alcohol figure at all, that is a gap, not a reassurance.
• Check the shelf life against the format. Unpasteurised product is short-dated by design — roughly 15 days ambient, 30 days chilled under one provincial standard. Twelve months means it was pasteurised, which kills the live culture and flattens the flavour.
• Buy it refrigerated and keep it refrigerated. Fermentation continues slowly in the cold; a jar left out will go sour and boozy.
• Judge it by the grain. Cooked glutinous rice should be distinct, soft but whole, sitting in cloudy liquid. Mush means over-fermented.

What we could not verify — please read before quoting numbers

• Nutrition per 100 g. A widely repeated figure of 100 kcal / 2.6 g protein / 0.2 g fat / 22.4 g carbohydrate is attributed to the Chinese food-composition tables, but we could not open the table, and a second source citing the same table gives 45 kcal / 1.7 g protein / 9.8 g carbohydrate. Xinhua puts commercial laozao at 100–130 kcal per 100 g. We are not publishing a single “official” number because the sources do not agree.
• Sugar content — reported as “almost always above 10% per 100 g, sometimes up to 37%.” Treat as indicative, not measured to a standard.
• Alcohol retained after cooking. No measured figure located. Do not assume boiling removes all of it.
• A national-level intangible-heritage listing. Every listing we found for a laozao or jiuniang technique is provincial or municipal, despite frequent claims of national status.
• National total output tonnage. Not found.

Sources

• McGovern et al., “Fermented beverages of pre- and proto-historic China”, PNAS, 2004-12-06 (Jiahu).
• Wang et al., PNAS, 2016-05-23 (Mijiaya).
Microbiology of Chinese jiuqu: ScienceDirect reviews, 2018; metaproteomics of baijiu jiuqu, PubMed, 2018.
• Amylopectin content of glutinous rice: MDPI 2025; ScienceDirect 2015.
• Fermentation runs: PMC11988636, 2025 (3.5% vol at 43 h); AGRIS, 2025 (1.83% vol).
• Draft national food-safety standard 酒酿(醪糟), cappma.org.cn, 2020-01-17.
• Hunan enterprise standard on shelf life, wjw.hunan.gov.cn, 2022.
• Food-safety and technique guidance, People’s Daily (peopleapp.com) and Xinhua.
• Industry scale: finance.sina.cn 2025-01-26 (Dazhu); xiaogan.gov.cn 2024-12-19 / 2025-09-19 (Xiaogan).