In China, particular cultivars of jiuqu are known as "starter cake" (曲饼; 麴餅; qūbǐng), "liquor product" (酒药; 酒藥; jiǔyào), or simply as qu.

[3] Qū is known as nuruk in Korea, much or marcha in India and Nepal, banh men in Vietnam, pacing in Laos, loog pang in Thailand, mochi kouji in Myanmar, mae domba in Cambodia, ragi in Indonesia and Malaysia, and bubo in the Philippines.

A book from the Shang dynasty (c. 17th–11th centuries BC) states that "to make wine or sweet liquor one needs qū nieh".

They may have formed separate elements of liquor production (both qū and nieh) or might refer to a single preparation made of fermenting sprouted grains (qu nigh).

Another almanac from the Eastern Han dynasty, the first-century AD Shuowen Jiezi records a character for qū modified to include the yellow chrysanthemum flower.

[3][5][8] The fourth-century Nanfang Caomu Zhuang has the earliest description of preparing a natural "herb ferment" with rice, used to make a special wine for marriage ceremonies.

"In [Nanhai, in Guangzhou] there are many fine wines, prepared not with yeast leaven but by pounding rice flour mixed with many kinds of herb leaves and soaked in the juice of Gelsemium elegans (冶葛; yěgé).

"[9] Making qū involves cultivating microbes in starchy materials and is a separate process that precedes the fermentation of grains and legumes into food or alcoholic beverages.

To keep the grains or dough relatively moist and warm, they are housed in closed straw-roofed huts and typically kept in straw baskets, stacked on wooden shelves, or simply placed on the floor.

The control of moisture and temperature levels and a lack of atmospheric access was recognized as vital to making consistently good qū as early as the Qimin Yaoshu.

At some stage in history, it was discovered that using small amounts (2–8% weight) of a previous successful batch to inoculate the current one gave more consistent results.

[11] Thus, the actual technique passed down through history unknowingly favored the growth and reproduction of the mold genera, organisms capable of excreting large amounts of functional enzymes onto their substrate.

Qū manufacturing techniques still vary widely, with each brewery or factory using a slightly different process and locally indigenous microflora, which in turn have generated diverse strains across China.

[3][5][6][11] As such, qū practices have evolved from: A fourth step was introduced in 21st century China, where aseptic laboratory conditions are used to mono-culture specific favorable strains of mold, yeast, and bacteria grown on independent, fortified substrates.

The use of microbial cultured starches for fermentation has a long history in East Asian countries, as evidenced by the diversity of foods and beverages produced.

Their mutualistic symbiosis with fermentative yeast and bacteria initiates the complex saccharification-liquefaction-fermentation process to produce the sought-after alcoholic liquid.

In the case of baijiu production, typical amounts of 15–25% qū are used, sometimes reaching as high as 50%, which consequently provides a major enzyme contribution to the mash to initiate catabolism.

Modern Chinese brewing adopted many practices to optimize production and a 'seed mash' is now commonly prepared where the qū is added, often along with the yeast (酵母; jiàomǔ or simply 酵; jiào), to a small amount of the substrate.

Relevant microbe species and genera prefer different climatic conditions, and domestication in the qū making process favored the development of regional microbiota assemblages across China.

[6][16] Molds are the most prevalent organisms found in qū and are considered to be the dominant enzymatic agents responsible for liberating glucose and other fermentable sugars from the source of carbohydrates used (along with the yeast Saccharomycopsis fibuligera).

Molds found in traditional Chinese fermentation starters include Aspergillus, Rhizopus, Amylomyces, Monascus, Absidia, Rhizomucor, and Mucor.

Yeast genera observed for qū in decreasing order of significance include Saccharomycopsis, Issatchenkia, Saccharomyces, Pichia, Candida and Rhodotorula.

[17][18][24][25][26][27][28] Bacterial species are present in large numbers in qū and are partly responsible for the breakdown of proteins and carbohydrates and the conversion of fermentable sugars into organic acids.

In turn, the starch ingredients used also alter the microbial ecology dictating both the type and the number of metabolites present, e.g., Aspergillus oryzae and Rhizopus oryzae both produce more starch degrading enzymes and are found commonly on 100% flour substrates, whilst Actinomucor and Mucor produce more proteolytic and lipolytic enzymes and are more abundant when pulse flours are added.

[6][11][16][18][21] Used mostly for the production of huangjiu and jiuniang and most popular in the southern provinces, xiao is added only to inoculate a fermentation and constitutes very little of the substrate in producing cereal wines (typically 3–8%).

Xiaoqu is the Chinese equivalent of what most other East, South, and Southeast Asian countries use as a fermentation starter, e.g. banh men, bubo, Murcia, ragi, nuruk.

The greater degree of microbial metabolism because of a longer, higher temperature conversion phase of incubation is also said to provide certain organoleptic qualities that would be otherwise unachievable in the final product.

The heavy use (50%) of large 5 kg (11 lb) bricks of daqu incubated at high temperatures is responsible for the pungent aroma and umami-like the flavor of Maotai.

Used mostly for huangjiu and rice vinegar, this starter gives the beverage a unique red or purple color due to pigments produced by members of Monascus.

Modern practice is to steep the rice in weak acetic acid solution for a short period to help create the optimum pH of 3–3.5 that favors Monascus growth.