PREHISTORIC FOOD PROCESSING TECHNIQUES -DISCUSSION ON THE ORIGIN  OF GRINDING TOOLS, MORTAR AND PESTLE

SUNG, Zhao-Lin

Chinese Historical Museum Agricultural Archaeology, Vol. 3, No. 47, 1997. 

(Translated by Elaine Wong; edited by Bryan Gordon) 

        Human foods comprise many different types and styles, even with certain ancient food processing procedures. When hunting was an ancient survival skill, food gathering and meat processing were simple, but food processing became more complex with agriculture due to seed separation from hard undigestible crop husks and shells, and their later grinding to flour using an ensemble of tools and techniques. New Chinese finds show 3 main food processing tools: metate and mano, mortar and pestle, and grinder, with another tool for processing tree bark. METATE People usually think the metate was invented by agricultural tribes, but it actually appeared in the Late Palaeolithic, when it was used for grinding wild food; e.g., Shanxi’s Xiachuan site (1). About 20,000 years ago, after the invention of agriculture, the use of the grinding tray as a crop processing tool spread widely. Neolithic stone tools for grain agriculture categorize broadly in 3 groups: soil preparing, harvesting and grinding. According to calculation, there are 216 such tools in Xincheng’s Peiligang site, including 88 metate and mano fragments (40.1%). There are 133 stone tool fragments in the E-gou site in Mixian, including 20 metate and mano fragments (20%). There are 1321 tool fragments in Hebei’s Ancishan, including 134 (10.4 %) metates and pestles, plus many finds in other Neolithic sites. All suggest many metates and manos, big outstanding tools of the time(2).China has several different metate types: Large footed metate, mostly rectangular with round ends, or round at one and pointed at the other. Skillfully crafted with four feet, it is the most beautiful and is mainly in Hebei’s Cishan, Henan’s E-gou and Shantung’s Beisun cultures, etc. Large, long footless triangular metate in the above area. Large (<50 cm) square or rectangular flat-surfaced saddle-shaped metate with turned-up ends found mainly in the northeast, northwest and Inner Mongolia (Fig. 1). 

Fig 1.

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        Irregular sized and shaped metate of rough-made natural stone mainly popular in the Yellow River Basin and surroundings. How was the metate used? The simple past answer is to put barley and millet on it and grind with a pestle to flour, but it is not that simple, as seen below. In Yunan, women of the the Dulong and Lu tribes still use the metate to grind barley, believing it must be dried before husking. They either put it on a roasting rack atop a fire to slowly dry, or stir it in a stone wok atop the fire for 30 minutes, after which it is ground 2-3 times on a metate until husks fall. Drying is needed to process barnyard grass and highland barley because they believe grass husk is more difficult to remove than regular barley. It is water-softened before processing, drained and embedded with red hot charcoal, with more charcoal on top to burst the husk and allow the grain to be ground. The Zhuang tribe’s method of processing highland barley is also quite complex: wash, dry and fry in an especially made 2-handled clay jar (Fig. 2). 

Fig 2.

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        The jar is preheated, partly filled and turned up, down and sideways to circulate the barley. Then, the barley is put on a winnow pan to exclude sand, then ground into flour on a mortar and pestle (3). In north China, large-grain millet also must be dried. In Loubuzongkedan (Dictionary of Traditional Mongolian Customs; Chap. 2), millet is called Mongolian rice and roasted. “After sand is heated in a wok until very hot, millet is added and fried to a crackling sound. After the grain is removed, husks are separated and a pestle used to obtain rice flour for daily consumption”. By deduction, ancient barley and millet needed drying or stir frying in some kind of sturdy cooking utensil, and then grinding (Fig. 3) in a metate. 

Fig 3.

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        Why do Peiligang culture metates have four feet? Historic data suggest the metate was placed on hide or in a woven bamboo basket, as done by the Dulong tribe, rather than on the floor. Feet prevent slipping, with grain easy to collect in the space between feet. 8,000 year-old Peiligang culture metates and manos are very finely made, but no footed metate occurs in Yangshao culture 2000 years later. Metates are not only rare, but irregular, coarse and puzzling, perhaps for two reasons: 

        (1) Yangshao agriculture is more advanced than Peilingjiang. Judging from the many Yangshao stone and clay knives, immense harvests needed more food processing. Metates were not only often used, but manos and dish-like grinders; e.g.s, 30 fragments in Sanmun Gorge’s Chujiakou, 2230 dish-like fragments in Meodikou Yangshao culture; plus other Yangshao sites. Some people believe they are scrapers, but they are obviously not, being blunt, thick and bladeless. Others think they are malletlike pounders but have no marks. Dish-like tools are mostly made with flat round pebbles scratched on one or both sides (Fig. 4). Hand-held, it is used inside vessels and leather bags with a metate to grind millet, with the same results as barley and millet metates and manos (4(. In the west Henan mountains, some farmers grind grain with their sole on a plank, but superior dishlike tools suggest they were the Yangshao grain processing tool. 

        (2) Metates and manos are rare and very crude in central China’s Late Neolithic, indicating their regression, but not other processing. On the contrary, excavation proves agriculture was well developed with increased production. Metates became obsolete because they were no longer important processors, being replaced by mortars and pestles. 

        *** (2) Mortar and pestle Although metate and manos have a long history and wide variety of uses, they are not mentioned in Wenxian (Chinese ancient literature). Only skeletal descriptions of them are found in ethnology study. The shortfall of metate is it can only process small amount of grain at a time and it often causes a lot of spillage. The grinding result is not very satisfactory. Along with the development of agriculture and increase in demand of grain processing, a new style of grain processing tool, the mortar and pestle emerged. In Wenxian, there are numerous mentioning of the invention of mortar and pestle: (Yi.Shi zi): “break the wood and make the pestle, dig the ground and make the mortar."(Shibun): “Yongfu made spring mortar and pestle."(Huntan New Theory): “Mixi created the benefit of mortar and pestle, later generation refined it. They borrow the body to practice. The profit increased ten times.” 

        From the above folklore, we can see that mortar and pestles were invented by Fuxi. They existed long before fishing-hunting-gathering period. Mortar and pestle are two different implements. Pestle is a wooden or stone rod. The mortar is created by digging a hole in the ground. Later on, stone mortar is invented. As for application, pestle is used by holding it with one or both hands and grind or pound the grains on the mortar, commonly known as hand hulling pestle. Such as the Ya tribe, Hali tribe, Yi tribe, Li tribe, etc., they are still using this kind of hand pestle (Fig. 5). Later on, a long pole is attached to the handle of the pestle and can be pedal by foot. Using the lever and fulcrum husk grains in the mortar and it became foot pestle. As it is mentioned in (Huntan New Theory) “Borrow the body to practice it," it meant foot pestle. This is already a more sophisticated method of husking rice. It appeared at a later time. To prove this, we have to research through archaeological material. A pestle was excavated from Bozhitou (Leopard’s head) remain site in Nanning. Stone pestle was also found in Zhengpiyan at Quilin Province. Both sites are 10,000 to 9,000 years old. This indicated the long history of the origin of mortar and pestle. During Neolithic time, mortar and pestle are widely used, such as the 90.2 cm long wooden pestle excavated at Hemudao. The end of the pole is 8.3 cm. The diameter of the center pole is 5 cm. This is the earliest wooden pestle found in China. Its shape and made is similar to that Henan province’s Li tribe’s wooden pestle (Fig. 6). This is about 7,000 years old. 

        What does a mortar look like? Presently, it is still not very clear. Basically, there are 3 different made: one is made with wood. None can be found now; one is “dig the ground and create a mortar," at Hemudao site, at level T224 a steel helmet “pole base” was found. Some scholars believe that this is known as “ground mortar”. Similar ground mortars are found at other location. Such as at a living quarter in Dadunzi in Jiangsu’s Pixian, there are 3 burnt soil pits. Inside there are still many wooden pestles. A ground mortar excavated at Hainan, Chenggou, Quangwu, is 20 cm in diameter and 5 cm deep. They have all been through the firing process. The perimeter is higher. There is mortar and pestle found at Hunghatao site in Yichang, Hubei Province. The pestle has turned into cinders. It is 1.4 meters long and in the middle section it is 14 cm wide. On the ground there are 2 ground mortar. The base is the shape of a basin. The surrounding edges are hard, smooth and shinny. It has all the characteristics of ground mortar. The other type is clay mortar, such as the clay mortar excavated at Hemudao. It is a big, thick and heavy large clay basin with big mouth and small base. It is 22 cm tall and the mouth is 42 cm wide in diameter. Some people believe that this is the clay mortar of the time. 

        Similar types of clay mortars were excavated at the Liangsui Cultural remain sites in Baichuan at Zhou Shan and Qian Shan at HangZhou. There was also a clay mortar (Fig. 7) excavated at Jujialing culture in GuanMiau at Hubei. Judging from the evidence, clay mortar definitely existed at the time. Because the nature of the clay is very fragile, will the mortar stand the force when it is using to pound the grain? Among the traditional cultural relics from the people in the Sunan area, there is type of “pit mortar". It is a type of mortar made with clay and can be used to pound rice grain. This proves that clay mortar can be used to grind grain. (Fig. 8) (5). 

        It is not difficult to see that mortars and pestles were invented at different places in Southern China. Presently, it is still difficult to determine where they were originated. It is certain that it originated from agricultural tribal hamlets. Is there also a type of ground mortar? Earth trough, or even burnt ground pit, are they able to withstand the forces of pounding by wooden or stone pestles? For this, we will explain through some of the materials from genealogy research. Among the Li tribe in Hainan Province, during the process of paddy rice production, they first harvested the stalks and dried it under the sun on a rack. Then they bundled them up in and stored in granary. Whenever, they want to eat rice, they will take the bundle out of storage and dry it under the sun on the ground in the courtyard. Then, they will husk the rice with their feet or beat the grains with a wooden mallet until they fall off the stalk. (Fig. 9). 

        After the grains fall off the stalks, they will be passed through a basket's colander to get rid of the impurities. The grains are then husked inside a wooden mortar to obtain the rice. During the process, the wooden mortar is placed in the courtyard. Grains are put inside the mortar. A female stand by the mortar, holding the wooden pestle by both hands, pounding the grains with up and down movements. In order to speed up the process of husking rice, sometimes more than one person will be performing the pounding task at the mortar. Here, the mortar and pestle are made with wood. It is made by hollowing out a section of a fragment of timber with iron ax. Then, a bit was chiseled away, a layer was burnt, chiseled away and another layer burnt until a mortar was created (6). In Yunan Province, Lafu tribe, Wa tribe, Hali tribe basically all use wooden pestle and mortar. For the Fuchung tribe, they dug an earth pit in the ground and lined the pit with a fragment of smooth leather. Then the grains are pored into the ground mortar and pounded by the wooden pestle. This kind of mortar can accommodate more grains and easy to dispense the rice with the leather. 

        Yi tribe in Sichuan Province used two types of mortar and pestle. They hollows out stone as mortar and used natural river pebbles as pestles. This type of mortar and pestle are mainly used to grind grains for flour or chilly for powder. It can be also used to grind salt. The other type of mortar and pestle is made with wood. The pestle was chiseled out of wooded rod with both ends thicker than the middle section. The wooden mortar is hollow out from a wooden section of a tree trunk. Through observation of the above evidence, ground mortar definitely existed. They are not created by deliberately digging into the ground. After the ground was dug, the hole was lined by a fragment of animal hide. This was the ground mortar is more steady and long lasting. From genealogical point of view, it seems as the majority of mortar and pestle are made with wood or stone. Prehistoric mortar and pestle in China are mainly made with wood with stone ones and ground ones as secondary. Since wooden ones are easier to decompose, they are no remains. This is why that there is a lack of food processing implements remains from Neolithic Period. The purpose of mortar and pestle is for processing millet, barley and sorghum. Just as mentioned in the above, the barley and sorghum have to be dried first before they can be husked. Millet and rice can also be grind into flour. Soya beans were also a food in prehistoric time. Its milk can be drink as soup. The beans can be eaten as cooked or used to make congee. On the whole they need to be processed with mortar and pestle. 

        (3) Processing and making Cassava Besides food processing tools such as stone matetes, mortar and pestles, pounding basins, etc., there are also many various types of implements among the archaeological findings. Pounding tools, chopping tools, and dishlike vessels are also found. In the past, they are all considered as production tools. In fact, they cannot be separated from the culinary culture, such as the culinary culture of Miao tribe in Quizhou. For example, in Quizhou, Miao tribe people gather many different kinds of food. Some of this food may be eaten directly. Some of them may be poisonous or taste bitter. They must be broken down, rinsed and filtered before they can be eaten. Cassava is carefully processed before it is eaten by Dulong tribe in Yunnan and Loaba tribe in Tibet. In the past, “Alei” is the main stable food of the Dulong tribe. “Alei” means powder of the “Dong” palm tree. “Dong” palm tree is a big and tall tree. It grows in the tropics or the sub-tropic climate. The tree matures very slowly. It takes about ten years to grow before the tree can be used. 

        The processing step involves 4 steps: 

        First step: chopping the tree Wood cutter would take chopping tool and choose the stronger and bigger “Dong” palm tree in the forest. First, make a chop on the root of the tree, if there is trace of sap on the blade, that means the tree can be made into cassava, and is worthwhile for chopping. The tree is laid down and the test cut is made on the trunk. Where there are sap oozing out is the place to cut off the stump of the tree. The remaining part of the tree will be used as raw material for making cassava. It must be dried thoroughly before it can be processed. Second step: chopping off the pith of the treeAfter chopping off the “Dong” palm tree, the tree is cut into several sections. Each section is about 7 to 80 cm long. 

        Then, each section is then cut into 4 fragments. After the fragments are dried, a male will take a fragment, step onto each end with his feet and cut down on the pith with his ax. If it is too tough near the bark of the tree, then, he will cut it away with his knife. 

        Then, he will put the tree pith on banana leaf and discard the tree bark. The ax is shape like the bill of a crane. It is made with a fragment of rectangle stone flake fastened on the end of a wooden handle and use it to hammer out the pith of the tree. This is an old fashion style dual purpose tool, similar to the type for pounding and chopping implement (Fig. 10). 

        Third step: washing out the cassava powder A work bench made with bamboo is built at the bottom of a mountain fall. The bench surface is made with woven bamboo. The edges on four sides are higher than the centre. There is a hole in the middle of the bench. The tree pith is placed on the middle of the bench. Banana leaves are placed on the sides of the work bench. A bamboo is used to pipe water from the fall continuously to the bench. People will process the food by repeatedly stomping on the pith and the starch is allow to sift through the hole in the center. Underneath the center of the work bench, there are 2 stones on the floor. A wide-mouthed basket is placed on top of the stones. It is a tightly woven basket. The bottom of the basket is connected to the sediment trough. The trough is made with bamboo or tree bark. It is constructed by linking different sections together. It is made to catch the starch dripping down from the bench. The first and second section of the trough catch the most starch (Fig. 11). 

        Forth step: drying the starchAfter stomping and sifting, starch remain in the trough is tightly wrapped in muslin. Then it is placed on a flat surface and weighted down by a heavy stone to press out all the water. When the starch is a fragment of lump and can be cut into 2 halves with a knife. It is then dried in front of a fire. This way it will be convenient to store it for later consumption. (7) Cassava can be used to make pancake or it can be mixed with other food for boiling. Zhuang Jia Bing (phenomenon inside the end of the northern area in Zhengnan) called “Dong” palm tree as “A Xio”. “A Xio” is a type of tree more than 10 feet tall, diameter as the size of a small timber about 5 or 6 inches. To eat it, first the tree will be chopped down and bark is removed. Then it is pound into powder and mixed with water. After 10 days of fermentation, it is used to make congee or used as condiment for consumption. It is very nutritious. Processed food similar to cassava occur long ago in ancient time. Food processing tool is usually pounding implement. Many crane bill shape hoes made with deer antler were among the excavation at Hemudao cultural remain in Zhejiang Province. The end of the hoe is affixed with a stone implement. It is probably a pounding implement (Fig. 12). 

        Meanwhile, at Yanshao cultural site, a large amount of basin shape vessels, round pounding implements, stone tools, some tools for softening leather, some tools for gathering and harvesting, and some food processing tools are found. (4) Other Grinding Tools There is kind of grinding tool often found in ancient Chinese archaeology. In the past, it is usually called pounding trough. Sometimes, it is called a sieve, or carved trough, or carved basin, or an implement for sediment. In fact, it is an implement for grinding. Chapter 6 of “Yu Pian” (ancient literature): “Lei (pounding) means to grind.”. In Ci Hai (the great dictionary) “Lei" means to crushed such as by using mortar and pestle. Mortar means "grind it into powder.” Mortar has an important position in food processing. The common factors among the grinding tools found in archaeology is that they are all made with grayish color clay pottery. On the inside wall of the pottery abdomen there are carved ridges. There is a spout at the mouth, but the shape and size are not uniform.

         There are 3 main categories:

        One type is cylindrical with large mouth. These vessels are small and limited volume. They are mainly found in Pingliang Tai in Huaiyang county of Henan Province, Meishan of Lingyu County, Xiawong Gang in Jichuan County, Wujialing culture in Jingshan County in Hubei Province.One type is dishlike, commonly known as dishlike mortar. This is a large vessel with a bigger volume. It is a larger type of grinding tool, such as the ones found in sites at Chengzhou’s Dahechuan, Wonghuan, Cuoli, Lutaigang in Fei Xian of Rouyang, 

        One type is basin shape. Only a few of these are found. They are smaller in shape with limited volume (Fig. 13) (8). They are found in Meishan in Lingyaun and Chinglungchuan cultural remain site. What are the purposes of these vessels? There are 2 sayings about this: One says it is for sediment after filtration. It was first use to make wine in it. 

        After fermentation, the wine is poured out; the other type of saying is that it is a mortar. It is used to grind mineral or food. It is worthwhile to research into the above sayings. First of all, although wine making was invented in ancient time and wine vessels have appeared, the wine at that time was usually sweet wine or water wine. These 2 types of wine do not need complicated filtration. Sweet wine is made by mixing dregs of wine with wine water when grain is fermented into wine. It can be consumed right away without filtering. Wine water is made with mixing water with brewed wine. Most commonly the wine is poured out and sipped with a bamboo. It is also consumed without filtered. Therefore it is said that the above vessels are for grinding and not for brewing wine. Are they mortars? This needs concrete analysis. Since the application of mortar is widely used, can it be that it is used for grinding minerals or is it used for grinding food? There is a big difference among the 2. Pottery is more fragile and less durable. It is not possible to use it for pounding and grinding minerals. Then, is it a grinding tool for grain processing? Since mortar and pestle are already very popular, these vessels are not for grinding grains.

         They serve other purposes and on this there are more explanation from genealogy. In tribal hamlets in Southern China and Southwest China, there is a very popular grinding tool. They vary in sizes and they have different names. 

        They are mainly divided into 3 categories: 

        One type is a clay pounding basin. It is made with clay. It is small, mostly the size of a rice bowl. Inside, there are carved ridges. They are for grinding chilly peppers, ginger, garlic and dried fishes. They are widely used in areas among the Yao tribe in Quangdong, Li tribe in Hainan, Yao tribe and Zhuang tribe in Quangxi, Tong tribe Miao tribe and Buyi tribe in Guizhou, Thai tribe and Yi tribe in Yuanan. It looks very much like mortar but very small. 

        One type is the grinding dish. It is very widely used in the above mentioned areas. It is also very popular among some tribal areas in Hunan Province. It is shape like a clay dish, inside there many carved ridges. After females crushed pumpkins, taro or tuber types of food, they hold the fragments in their hand and grind them in the dish and let the starch flow out of the mouth. 

        Another type is grinding crock. These are larger crock and made with fired pottery. Inside the abdomen there are also ridges. After harvest in Autumn, Zhuang tribe, Buyi tribe, Miao tribe, Yao tribe and Tong tribe wash fresh taros and white potatoes very well and grind them starch. After filtering, water from them sediment is poured out and filtered through fine cloth again. The remaining sediment is turned into flour and used to make a fine sheet of dough, or use the flour to make noodles. In Fujian and Quangdong, there is a type called “tea pound”. It used a tea dish, which is a combination of pounding basin and rod. They are both made with clay. Pounding basin is dishlike. It is thick and heavy. The inside wall has carved ridges. When drinking tea, tea leaves, raw rice, ginger, salt, and sesame are put inside the basin and crushed by a rod. After boiling and filter it is ready to be served. Here, the food processing is not grinding but pounding. (9) 

        The above mentioned pounding basin, grinding dish and grinding crock all indicated that these tools are first of all mainly for grinding food. Secondly, they can be used for sedimentation. Clearly specified that one vessel serves two purposes. It has multiple uses. The ridges inside the abdomen of the vessel are for grinding purposes and for filing vegetables. Within this, there are 2 types of sayings: one is grinding method. Food is held by hand and grind over the ridges. The other method is to use pounding rod to pound the food inside the pounding dish. These materials are important testimony to the finds of pounding basin in archaeology. Then, what kind of food was processed by the grinding implements during ancient time? They are mainly taro and tuber types of food. 

        In the vast land of China, tuber types of food are widely grown in many areas. They are one of the most important food for ancient people. In the beginning, wild taro tubers were gathered. Such as in Yuanan, Lagu tribe collected more than 10 kilos of wild tuber (Zhurou Xian Zi, Minzhu) Goashan tribe in Taiwan, use taro tuber as snack. “When hungry uses ginger to mix in water to drink and eat it with tree and leaves. This can be carried out for a month, or roast taro tuber food. Later on, taro tubers were cultivated. It is not difficult to see that taro tuber is an important food in ancient time. Besides roasting the tuber as food, they can be grind, filter and processed into flour. This way it is more suitable for consumption for it is easier to digest. Therefore, the basin and dishlike grinding implements found in archaeology are collectively known as grinding crock and grinding dish. It is a type of food processing tools for taro type tubers. 

        As for the smaller pounding basin, they may be used for grinding condiment such as salt and chilly peppers. Because they are too small, therefore they are not for processing food. 

Bibliography

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(3) Tibet Social History Research Committee: 5th Report of Zhuang tribe Social History Research. Tibet People’s Publishing Society, 1988, p. 230.

(4) Ban-Buo Museum, etc. in Xian: Jiang Zhai. Wenwu, 1988, p. 80.

(5) Zhang, Liang & Wong, Shou-Ren: Research on Mortar and Pestle in Agriculture. Kaogu vol. 2.

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(8) Nie, Xin-Min: Shallow Filtration Vessel. Chinese Archaeology Research Magazine, pp. 210-213,1987. San-Qin Publishing,.

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