Jiuniang is a sweet, soup- or pudding-like dish in Chinese cuisine. It is also known as sweet wine or sweet rice wine. It consists of a mixture of partially digested rice grains floating in a sweet saccharified liquid, with small amounts of alcohol (1.5–2%) and lactic acid (0.5%). It is made by fermenting glutinous rice with a starter called jiuqu containing Rhizopus oryzae or Aspergillus oryzae and often yeast and bacteria.
It was first developed as a by-product of mijiu production and generally speaking is partially digested rice from a young rice wine (or vinegar) ferment. If eaten quickly or held at 10 degrees or less, which halts the fermentation, the product can be consumed as jiuniang. If the temperatures are raised and fermentation continues, jiuniang will eventually produce rice wine or rice vinegar. Jiuniang is most commonly made and consumed in the winter, where fermentation can be halted easily.
Jiuniang is often made with sweet osmanthus flowers in a dish called guihua jiuniang. It is also often served together with small unfilled tangyuan during the Dongzhi Festival, a Chinese winter holiday dedicated to the ancestors. All forms of jiuniang are typically eaten with a spoon.
An almost identical food product is made in Southeast Asia. In the Philippines it is called binubudan, in Thailand it is called khao mak, and in Malaysia and Indonesia it is called tapai. In Indonesia it most popularly made with purple/black glutinous rice and called tapai ketan.
It is also similar to the southern Vietnamese dish cơm rượu, which usually contains balls of rice. It is also similar to Korean sikhye and Japanese amazake, although these are thin in texture and considered drinks rather than soups or puddings.