Quern
What is a quern?
When did the use of querns begin?
What are the two main types of querns?
What materials were used to make quern stones?
What was a unique use for miniature rotary querns?
Quern, ancient device used for dehusking and grinding grains. The basic unit of a quern consists of two stones that rub against each other, crushing the grains placed in between them. The use of querns dates back to the early Neolithic period, or the New Stone Age (10,000 to 3,000 ʙᴄᴇ), coinciding with the adoption of a more agrarian lifestyle and the inclusion of more grains and cereals in the human diet. In addition to processing grains, querns have been used to pulverize spices and herbs, natural dyes and pigments, and even mineral ores. Querns were in use in the British Isles and parts of Europe until the 20th century ᴄᴇ and are still used in many parts of the world.
Types of querns
Querns can be classified into two broad types based on the direction of motion applied in crushing grains.
Saddle querns
The simplest of designs involves the non-rotatory to-and-fro motion of a rounded stone (called the muller) on an elongated stationary stone bed. The grinding surface of the stone bed was often concave, which gave the name saddle quern to this type of device. Saddle querns are very primitive, and quern stones dating back to the 10th millennium ʙᴄᴇ have been found in Syria. They were used in ancient Egypt and were a common household device in Britain throughout the Bronze Age. These querns were larger and deeper and resembled troughs in prehistoric Scotland and Cornwall. Saddle querns have been discovered in the ruins of the Harappan civilization. The fundamental design and working principle of this tool survive in the present-day silbatta of India and the metate and mano of Mexico.
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Rotary querns
In Europe the saddle quern was largely replaced by rotary querns in the 1st millennium ᴄᴇ. In these devices, the upper grinding stone was rotated on top of the lower stone around a central spindle using a handle. The unprocessed grain was fed into the upper stone through a hole or a hopper, and the ground grain emerged at the edges, between the two stones (or rarely, through a spout in the lower stone). Large grinding mills, operated by animals and enslaved people and mentioned in ancient Greek and Roman texts, probably gave rise to rotary querns. Cato the Elder describes a 2nd-century-bce rotary quern consisting of a concave lower stone and a convex upper stone, turned by a pair of donkeys. Many such large querns have been found in the ruins of Pompeii. Three main types of smaller rotary querns evolved from these elaborate mills—the beehive quern, in which the grinding stones were hemispherical and the quern looked like a domed bee skep (human-made beehive of grass or straw); the pot quern, in which the lower stone was a crucible; and the disc quern, in which the two stones were flattened discs. This latter type is still in use in Asia (as the chakki in India and the janto in Nepal).
Stones used in querns
A stone’s durability and resistance to wear determined its suitability for use as a quern stone. The stone also needed to be suitably granular so that the quern would have the required abrasiveness. Sandstones, basalt, granite, schist, and limestone were widely used to make querns in ancient Europe and Egypt. The Romans introduced lava quern stones in Britain, which remained in use until the end of the 3rd century ᴄᴇ. The grinding surface of quern stones was often pecked or chipped to improve their grinding efficiency, particularly when they had been worn flat. Remains of Roman-era querns with symbols engraved on the sides have been discovered in Britain.