China’s long history of making and drinking alcohol can be traced back to the early Neolithic time (ca. 9,000–7,000 cal. BP). Residue analyses of ceramic globular jars from the Jiahu site in Henan province and the Qiaotou site in Zhejiang province indicate that such vessels once contained mixed fermented beverages of rice, honey and fruit at Jiahu (McGovern et al., 2004) and rice-based fermented beverages mixed with Job’s tears and tubers at Qiaotou (Wang et al., 2021). During the middle Neolithic period (ca. 7,000–4,900 cal. BP), fermentation and drinking vessels became more diverse regionally. In the middle Yellow River region, a rather limited number of forms of jiandiping amphorae were used for fermentation and communal drinking in the Yangshao culture (Liu, 2021). In the lower Yellow River region, on the other hand, a variety of vessels with exquisite craftmanship were used for brewing, heating, pouring, and drinking alcoholic beverages, coinciding with the development of social differentiation in the Dawenkou culture (ca. 6,100–2,600 cal. BP) (Liu, 2017; Liu et al., 2021b). As societies became more stratified during the late Neolithic period of the Longshan culture (ca. 5,000–3,900 cal. BP), the alcohol-related vessels also became more elaborate in form, specialized in function, and often appeared in concentration at large sites or elite burials. These parallel developments suggest that consumption of alcoholic beverages was an important part of feasting ritual activities at political and economic centers (McGovern et al., 2005; Underhill, 2018; He et al., 2021).

Feasts were a significant part of various rituals in prehistory, and the artifacts associated with such activities are important material remains for studying ritual behaviors and social relations in the past (Dietler and Hayden, 2001; Hayden, 2014). The ceramic assemblages for alcohol consumption, which include serving vessels (e.g., gui and he pitchers for heating and pouring liquid) and drinking vessels (e.g., jue and bei cups), became widespread in most of the Yellow River valley from the late Neolithic to the early Bronze Age. Chinese archeologists have studied these vessels for decades, exploring their origins and development mainly by studying typological changes (Gao and Shao, 1981; Du, 1990, 1992). These studies demonstrate that these vessels were the prototypes of the first bronze ritual vessels, such as gui, he, and jue, found at the Erlitou site in Henan province, the development of which marked the beginning of the Bronze Age in north China. Thus, ceramic drinking vessels laid the foundation for the emergence and institutionalization of bronze ritual vessel types, and this transformation first took place at the Erlitou site.

Despite of the importance of these vessels, there has been little scientific analysis of their functions. It is still unclear how these hypothetically alcohol-related vessels were used and what brewing methods were practiced in the Erlitou culture. To address these issues, this paper aims to provide direct evidence of the alcohol-making technology and drinking practices at the Erlitou site. By analyzing the residues on ceramic vessels and their archeological contexts, the results will shed new light on the production and consumption of alcoholic beverages at Erlitou, and on the social function of ritual feasting in the emergence of state-level civilization.

Our analysis revealed abundant microfossil remains, including starch granules, phytoliths and fermentation-related fungi (molds and yeast cells).

Based on the above analyses of various microbotanical and microbial remains in the residues, we observed the following phenomena.

(1) Fermentation method: The two most common methods of brewing cereal-based alcoholic beverages in China include the use of malts and the use of qu starter as saccharification agents (Ling, 1958). According to previous studies, if malts were used there may be husks left in the fermentation liquid, so there may be many husk phytoliths in the residues of fermentation vessels. If qu starter was used, there may be fermentation-related molds in the residues (Wang et al., 2016; Liu et al., 2019; Liu, 2021). Monascus has traditionally been used for brewing rice-based fermented beverages in China (Bao and Zhou, 2007, p.166–169). We found mold components in 15 out of 16 vessels, among which cleistothecia and hyphae of Monascus were the most common elements. The co-existence of rice starches and phytoliths with Monascus components in our samples suggests that the brewing method at Erlitou likely used qu starter with Monascus molds and rice as the fermentation agent.

The fermented beverages made by Monascus molds and rice are red, and are called hongqujiu, red mold beer. In modern times, red beer is mainly produced in Zhejiang and Fujian provinces in southern China. It is generally believed that this brewing method originated in the lower Yangtze River region and later dispersed to other regions (Bao and Zhou, 2007, p. 104–110). According to the published archeological data currently available, the history of using Monascus molds as starter for brewing beer in the Yellow River Basin can be traced back at least to the middle phase of the Yangshao culture, such as the Xipo site in Lingbao and the Dingcun site in Mianchi, all in Henan Province, dating to ca. 6,000–5,100 years ago (Feng et al., 2021; Liu et al., 2021a). Thus, the alcohol-making method at Erlitou apparently inherited the fermentation tradition that had already existed for thousands of years in the Central Plains.

It is also interesting to note that some wide-orifice vats and narrow-orifice jars both were likely related to the brewing process, given that residues from such vessels tested in this study contained abundant Monascus mold components and yeast cells. These vessels are most likely to have facilitated the semi-solid-state fermentation (semi-SSF) process, during which vats were used for primary fermentation, and jars for secondary fermentation and storage. This brewing technique is still practiced in southern China today (Bao and Zhou, 2007, p. 155–260).

The semi-SSF method is different from the earlier liquid-state fermentation technique, which used globular jars and jiandiping amphorae as fermenters during the early and middle Neolithic periods (Liu et al., 2019; Liu, 2021). The Erlitou brewing method appears to be consistent with the brewing tradition that uses Dakougang wide-orifice vats as the fermenter for making hongqujiu red beer, which may have originated in the Lower Yangzi River valley and spread to northern China. This hypothesis is based on the evidence that Monascus molds and rice starches have been found in the residues from wide-orifice vats at Xipo in Henan (Feng et al., 2021) and a Dawenkou culture site at Yuchisi in Anhui (Liu et al., under review¹).

(2) Rice for beer brewing: Rice starch and rice husk phytoliths were found in 14 vessels, accounting for 87.5% in ubiquity, indicating that rice was the basic raw material for alcohol making. The microfossil analysis of the floors from a large public building and associated ceramic vessels of the Yangshao culture at the Huizui site, about 15 km east of Erlitou, showed that rice was one of the ingredients for alcohol making (Liu et al., 2018). Therefore, using rice to make alcohol may have been a local tradition.

In the Yiluo region, where Erlitou is located, rice has never been a major crop. Prior studies have identified limited remains of carbonized rice grains in only a few locations at late Yangshao, late Longshan, and Erlitou culture sites. In the flotation samples from 15 sites contemporary with Erlitou in the Yiluo region, only 19 rice grains have been recovered from five sites (Lee et al., 2019). In contrast, flotation samples from the Erlitou site have revealed abundant rice, totaling 5,687 grains, and accounting for 23.9% of the total unearthed plant seeds and 30.8% of the total unearthed crop seeds, second only to millet (11,059 grains) (Institute of Archaeology CASS, 2014). Such a clear discrepancy between Erlitou and other sites in the quantity of rice remains raises a question about the sources of rice. It is unlikely that the large amount of rice unearthed in the central area of Erlitou was produced by Erlitou urban residents themselves; thus, rice may have been a tributary item obtained from small and medium-sized settlements that mainly engaged in agricultural production in the Yiluo region and beyond.

(3) Wheat for beer brewing: Triticeae starches and/or dendriform phytoliths (from husk of Pooideae, possibly Triticeae) were found in ten vessels, accounting for 62.5% in ubiquity. They may come from wild Triticeae grasses or domesticated wheat/barley. Wild Triticeae seeds or domesticated barley were not found in flotation samples from sites dating to Erlitou period in the Yiluo basin (Institute of Archaeology CASS, 2014; Lee et al., 2019), so it is reasonable to rule out these two taxa as possible origins of these microfossil remains. Wheat was introduced to the Central Plains from West Asia through Central Asia in the late Neolithic times, around the third millennium BC (Liu et al., 2017). In the Yiluo region, carbonized wheat seeds dating to the Erlitou period have been uncovered from flotation samples, but in very small quantity. Only three wheat grains were found in Phase IV deposits at the Erlitou site, while four wheat grains were unearthed from two other Erlitou culture sites, suggesting that wheat may have been cultivated locally in limited quantities (Institute of Archaeology CASS, 2014; Lee et al., 2019). Therefore, it is likely that the Triticeae starches and dendriform phytoliths in the vessels were from wheat, which may have been produced locally in the Yiluo region and/or was obtained from places farther away. We speculate that in this early stage of the introduction of wheat to the Yiluo region, its function may have been special, perhaps primarily related to alcohol making.

(4) Millet and Job’s tears for beer brewing: Residues containing millet starches and husk phytoliths appeared in six vessels, with two husk phytoliths identifiable as broomcorn millet, together accounting for only 37.5% in ubiquity. In contrast, the abundance of millets found in flotation samples from the Erlitou site show that millets were the main crops, of which foxtail millet accounts for 60.0% of unearthed crop seeds, and broomcorn millet accounts for 8.3%. According to previous studies, the raw materials for alcohol-brewing in the Yellow River region during the Neolithic period were primarily broomcorn millet, rice and Triticeae (Liu et al., 2019; He et al., 2021; Liu, 2021). Therefore, we speculate that broomcorn millet may have also been one of the main ingredients in alcohol-making at Erlitou, although it was used less frequently than were rice and wheat.

(5) Job’s tears and snake gourd roots for beer brewing: The use of Job’s tears, snake gourd root, and other tubers for alcohol production can be traced back to the early and middle Neolithic periods (Liu et al., 2019; Liu, 2021). We found very low quantities of these in this study: Job’s tears starches and phytoliths (large Variant 1 type) were found in only one vessel, and snake gourd root starches in two vessels. These observations suggest that these traditional alcohol-making ingredients were still in use, but infrequently, at Erlitou.

(6) The relationship between starch and phytolith remains: In several cases, starch granules and phytoliths from rice, wheat, millet, and Job’s tears coexisted in the same vessels, increasing the reliability of taxonomical identification. However, there were far greater numbers of starch granules identifiable as rice, wheat, millet, and Job’s tears (n = 321, 129, 25, 9, respectively) than there were husk phytoliths from the corresponding plants (n = 125, 7, 2, 1, respectively). This observation suggests that rice, wheat, millet, and Job’s tears were probably hulled before entering these vessels, and that the existence of small amounts of husk phytolith is likely the result of insufficient hulling, rather than a result of using germinated cereals as saccharifying agents. This, along with the abundant Monascus mold elements found in the residues, indicate that qu starter was used for alcohol fermentation.

(7) Use of herbal qu starter: Most vessels revealed many phytoliths from stems and leaves (e.g., elongated psilate/sinuate morphotype), which cannot be used for taxonomical identification. Some of them may come from herbs related to making qu, commonly referred to as caoqu, or herbal qu starter. Molds and yeasts naturally attach to the stems and leaves of some plants, and the traditions of making qu by adding stems, leaves, and seeds of various wild plants can be found today in the Yangzi River valley and among the indigenous peoples in Taiwan (Ling, 1958; Yu, 2003). At present, we cannot further identify these phytoliths in our samples.

(8) Alcohol-brewing ingredients and luxury foods: When further comparing the plant types in different vessels, we can see that Jar2 has the most diverse ingredients, including rice, millet, Job’s tears, Triticeae and snake gourd root, while other vessels revealed mainly rice, Triticeae and millet. The starch types with highest counts and ubiquity were from rice (321, 87.5%) and from Triticeae (129, 50.0%), suggesting that rice and Triticeae (likely wheat, as discussed above) were the most common basic raw materials, while other plants were used much less frequently (Figure 7). In the Yiluo region, which is part of the Loess Plateau suitable for dryland farming, millets were the major cultivars in subsistence economies, while rice and wheat were minor crops (Lee et al., 2019). It is possible that rice and wheat were produced mainly for alcohol production, given that rice has been essential for making qu starter with Monascus mold and also used as the main ingredient for brewing red rice beer (Bao and Zhou, 2007), and wheat has also been a traditionally preferred cereal for making qu starter (Jin et al., 2017). The importance of rice and wheat in alcohol production suggests that they were especially needed for feasting activities of the Erlitou elites. Such characteristics, i.e., being in high demand by elites but not widely available to commoners, are typical traits of luxury foods (Veen, 2003).

(9) Drinking practice and social relations in transition: Compared to the alcohol production and consumption in the previous Neolithic period, several changes in raw materials of fermentation, in drinking vessels, and in consumption practices appeared during the Erlitou period. First, using multiple grains and tubers/roots to make alcoholic beverages was a long-lasting tradition during the Neolithic times in the Yellow River region. Based on the analysis of the jiandiping amphorae of the Yangshao culture, brewing ingredients included mainly broomcorn millet, together with rice, Job’s tears, Triticeae, snake gourd root, yam, and lily, among others (Liu, 2021). This Neolithic tradition, using mostly staple foods for alcohol making, was gradually replaced by methods that used only grains as brewing ingredients in the historical period (Bao and Zhou, 2007). This transition may have taken place in the Erlitou culture, when rice and wheat became primary ingredients, while millet and roots/tubers declined in use. If rice and wheat, being luxury foods, were obtained by Erlitou elites from tribute goods, the ability to make alcoholic beverages with such food items would have demonstrated their prestige, wealth, and power. Second, during the Neolithic Yangshao culture, jiandiping amphorae used for both production and consumption of alcoholic beverages were ordinary vessels, frequently found in all archeological contexts. Communal drinking through reed straws may have been a common practice in feasting activities which took place in public buildings or central plazas in settlements. Such a feasting tradition apparently emphasized group solidarity and social inclusion (Liu, 2021). In contrast, the alcohol-related pottery assemblage at Erlitou is composed of specialized vessel forms used for brewing, storing, serving (heating and pouring), and drinking, suggesting more elaborated procedures involved in feasting activities. Serving and drinking vessels made of white clay were likely also luxury items, which have been found mainly in the walled palatial areas and elite burials. These changes indicate that the feasting activities may have been socially exclusive in nature. Considered together, serving luxury drinks with prestige utensils in socially exclusive spaces may have become the focus of ritual feasting held by the Erlitou elites, which also emphasized social status, wealth, and power. These changes in drinking materiality and social values occurred in the late Neolithic Longshan culture (Underhill, 2018), and became more formalized and perhaps institutionalized at Erlitou, coinciding with greater social differentiation and heightened elite power at the time of early state formation.

Based on multiple lines of evidence from microfossil analyses in this preliminary study of Erlitou pottery vessels, we can tentatively reconstruct the processes of alcohol production and consumption at Erlitou, the first Bronze Age urban center in north China. Various ceramic vessels were involved in these processes. Dakouzun wide-orifice vats were used for fermentation, likely in semi-solid-state fermentation conditions; zun narrow-orifice jars for storage of the beverages; gui and he pitchers for heating and pouring; and jue cups for drinking. The brewing method likely first prepared qu starter with Monascus mold, also added herbs to aid fermentation. The brewing ingredients may have included primarily rice and wheat, sometimes mixed with broomcorn millet, Job’s tears and roots of snake gourd. Rice and wheat may have been partially received as tributes from the surrounding settlements in the Yiluo region and beyond.

The use of precious white clay to produce alcohol-related serving and drinking vessels also indicates that alcohol consumption was a high-ranking elite activity. Such feasting events involving fermented beverages, held in palaces and associated with elite burial rituals, coincided with the growth of elite power and social stratification at Erlitou. Alcohol apparently played a significant role in the emergence of the first Bronze Age state in China, a research topic which has not yet been explored adequately. This study opens a new window for further investigation of alcohol-related material remains and social activities, as well as their relation to state formation in prehistoric China.

The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.

LL conceptualized and designed the study. LL and YH analyzed samples and wrote the manuscript. HZ and HX excavated the site and provided the materials and data. All authors contributed to the article and approved the submitted version.

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

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