Huangjiu

This is the formal classification for all Chinese wines. There are five categories: dry, semi-dry, semi-sweet, sweet, and extra-sweet.[5]

• Dry (Gan, 干 / 乾): with sugar content no greater than 1%. This type of rice wine has the lowest fermentation temperature. An example of this kind is Yuanhongjiu (元红酒, literally "Champion's Red Wine"), a specialty of Shaoxing, so-named because being successful in the imperial examination is a great cause for celebration and fame (red) and as well, traditionally the wine jars are painted red.
• Semi-dry (Ban Gan, 半干 / 半乾): with sugar content between 1% and 3%. This type of huangjiu can be stored for a long period of time and encompasses most of the varieties of huangjiu that are exported from China. An example of this variety is Jiafanjiu (加饭酒, literally "Added Rice Wine"), a variation on the Yuanhongjiu that involves adding more rice in fermentation. The jiafanjiu is traditionally used for ceremonies, such as child birth, engagement, and funerals.
• Semi-sweet (Ban Tian, 半甜): with sugar content between 3% and 10%. The longer the semi-sweet huangjiu is stored, the darker its color becomes. This variety of huangjiu cannot be stored for long periods of time. An example of this kind is Shanniangjiu (善酿酒, literally "Best Made Wine"), a specialty of Shaoxing which partly uses vintage Yuanhongjiu instead of water.
• Sweet (Tian, 甜): with sugar content between 10% and 20%. An example of this variety is Feng Gang Jiu (封缸酒, literally "Conceal Earth Jar Wine"). In comparison to previous types of huangjiu, sweet huangjiu can be manufactured all year round when using traditional production methods.
• Extra-sweet (Nong Tian, 浓甜): with sugar content equal or greater than 20%. An example of this variety is Xiang Xue Jiu (香雪酒, literally "Fragrant Snow Wine").

• Xiaoqu (小曲 / 小麴; pinyin: xiǎo qū): Wines inoculated using rice cultured with Rhizopus, yeast, and other microorganisms. The mixture generates less heat, so they are mostly used in southern China.
• Daqu (酒曲 / 酒麴; pinyin: jiǔ qū): Wines inoculated using rice cultured with Aspergillus oryzae and yeast. Almost all popular alcoholic drinks in China belong to this type.
• Hongqu (红曲 / 紅麴; pinyin: hóng qū): Wines that are flavoured and coloured with Monascus purpureus or other red rice molds of the genus Monascus.

• Tangfan (烫饭 / 燙飯; pinyin: tàng fàn): The steamed rice used to make the wine is cooled in the open air until it is still relatively warm before processing.
• Liangfan (凉饭 / 凉飯; pinyin: liáng fàn): The steamed rice used to make the wine is quenched with cold water before further processing. The unfiltered mash for this wine is sometimes eaten as a dessert or used as an inoculant for other Chinese wines.
• Jiafan (加饭 or 喂饭; pinyin: jiā fàn or wèi fàn): Steamed rice is continuously fed into a fermenting mixture (up to three times), which produces a sweeter wine.
• Fortified: Baijiu is added to the fermenting mash, which increases the concentration of alcohol in the mash and halts the fermentation process. This leaves a significant quantity of unfermented sugars, thus producing an especially sweet tasting wine.

The three main ingredients of Chinese alcoholic beverages are the grain, water, and qu. Other ingredients may also be added to alter the color, taste, or medicinal properties of the final product.

During their creation, storage, or presentation, Chinese alcoholic beverages may be flavored or seasoned. Use of fruit is rare, particularly compared with Korean wines, but medicinal herbs, flowers, and spices are much more common. Well-known examples include cassia wine (flavored with sweet osmanthus blossoms and consumed during the Mid-Autumn Festival) and realgar wine (dosed with a small amount of arsenic sulfide and consumed during the Dragon Boat Festival).

The earliest grains domesticated in China were millet in the north and rice in the south. Both are still employed in production of alcohol. Modern production also employs wheat, barley, sorghum, and coixseed.

For huangjiu, the grains are degermed and polished of their bran. They are then soaked and acidified with the aid of lactobacillus or through the addition of lactic acid into the soaking liquid. (Acidification is done to discourage the growth of other microbes on the grains, which can spoil the resulting liquor by creating undesired flavors in it or rendering it poisonous.) This process produces a taste and mouth-feel distinct from other forms of rice wine.

Water hydrates the grains and enables fermentation. The pH and mineral content of the water also contribute to the flavor and quality of the drink. Many regions are famous not only for their alcoholic beverages but also for the flavor and quality of their water sources. Emphasis is placed on gathering the cleanest water directly from springs or streams or from the center of lakes, where the water has been exposed to the least amount of pollutants. Water should be low in iron and sodium, with a higher proportion of magnesium and calcium ions as part of its total mineral content.

The fermentation starter, known in Chinese as Jiuqu or simply as Qu, is usually a dried cake of flour cultured with various molds, yeasts and bacteria. In the production of huangjiu it is crushed and added to inoculate the cereal substrate to initiate fermentation into liquor. The various molds and filamentous yeasts found in Qu exude enzymes that digest the substrate into sugars that are in turn, fermented into alcohol by other yeasts and bacteria.[14]

There are three main types of starters:

• Xiaoqu (小曲 / 小麴) or Small Starter, a small cake (10-100g) of rice flour (or if wheat flour, termed Maiqu), cultured with microbes and incubated for a short period at relatively cool temperatures. The dominant starter for huangjiu.[14]
• Daqu (大曲 / 大麴) or Large Starter, a large cake (1–5 kg) of wheat, wheat and pea, or barley and wheat flour, cultured with microbes and incubated for a longer period at relatively high temperatures. The dominant starter for Baijiu, but often used in huangjiu in combination with Xiaoqu. Its use will significantly alter the organoleptic qualities of the ensuing wine.[15]
• Hongqu (红曲 / 紅麴) or Red Starter, are dried, mold-encrusted rice grains cultured with microbes, The dominant mold, Monascus purpureus, creates a red pigment which colours the ensuing liquor in shades or red to purple. Often used in conjunction with Xiaoqu to make red cereal wines.[16]

Prior to the actual brewing of the liquor, another small batch of grain is prepared to produce the "seed mash" (酒母, jiǔmǔ). Seed mash is produced by soaking and acidifying glutinous rice and other grains, then steaming them on frames or screens for several minutes. This cooks the grains and converts their starch into a gelatinized form that is more easily utilized by the starter culture. The inoculation temperature of the steamed grains is tightly controlled as it alters the flavor character. This is usually done when the grain has been doused with cold water and cooled to between 23 and 28 °C, which is considered the optimal initial fermentation temperature for the seed mash.

After the little starter is added, it is allowed around two days to begin the saccharification, acidification, and fermentation of the grains. Inoculation with the first starter partially liquifies the steamed grains, which is the signal to add the big starter as well as more water to form a thick slurry. This slurry is carefully stirred by a brewmaster to aerate and maintain an optimal level of oxygen and carbon dioxide in the mixture, as well as to maintain an even temperature throughout the fermenting mass. The slurry is periodically stirred over the course of a week. The stirred slurry is then allowed to go through a more thorough fermentation for approximately one month, following which the pH drops to around 3.4 and the alcohol content rises to approximately 15%. This is the seed mash that will be used to brew the main mash.

More soaked and acidified rice is prepared in the same fashion as in the seed mash. The grain is then either cooled with cold water or left out on a flat surface, depending on the type of huangjiu being produced, as the cooling method alters the flavor and mouth-feel of the resulting drink. The seed mash, an additional big starter, and fresh water is then mixed into this grain in large, glazed earthenware pots up to 2 meters (6 ft 7 in) in diameter and height. The mixture is pounded on the sides of the pots.

Similar to the production of Japanese sake, saccharification and fermentation usually happen in the same mash concurrently, as the seed mash and starter act on the cooked rice. The mixture is then left to mature in earthenware jars for a length of time from several months to several decades before being bottled and sold.

Northern breweries often use three big starters, rather than an initial little starter. Large factories typically employ air blowers to cool the second batch of grain rather than using cold water or leaving it out to cool.

The brewery may also separate the saccharification and fermentation of the grain, similar to brewing. If this is desired, the seed mash is typically not used, since a main mash will never be produced. Instead, a mash of water, steamed glutinous rice, and other grains is inoculated with rice that has already been cultivated with the mold Aspergillus oryzae or molds of the genus Rhizopus and certain strains of Lactobacillus. When mixed into the mash, the molds cultivate the mixture and convert the starch in the grains into sugar and lactic acid. This sweet and slightly sour liquid is drained and reserved, while additional water (and sometimes also malt) is added to the mixture. The process is repeated until the grains are exhausted. Yeast is then added to this liquid in order to convert the sugars in the liquid to alcohol.