Cauldrons and the Development of Cast Iron for Domestic Use
By: Jacob Selmer
Last revised: 10/31/2003
The study of early metallurgy and metalworking often focuses on military and industrial applications. However, the everyday uses of metals are sometimes overlooked. In particular, the cauldron played an essential role in day-to-day life. Modernly, manufacturers make these out of cast iron, but Europeans did not begin using this material until early in the fifteenth century and mass production of cast iron did not happen until the eighteenth century. This report discusses some of the history and importance of cauldrons and focuses on the development of cast iron for everyday use.
Cauldrons in Celtic life played an important role. More than just essential cooking vessels, they could also have magical qualities attributed to them. Cauldrons and chalices appear in many Celtic tales and rituals. Early Celtic metalworkers generally crafted these cauldrons from brass or bronze, which they either cast into a single piece or forged in multiple pieces and joined with rivets and solder. Archaeologists found one such cauldron at Gundstrup, Denmark (Figure 1). This highly decorated vessel from the first century B.C. consists of thirteen silver gilt panels, combining to create a 27-inch diameter cauldron (Lang, 83-85, Eluere, 116-117). The expense of Celtic cauldrons made them unaffordable for most people and consequently, the craftsmen often took great care to make them works of art.
Europeans in the middle ages cast copper alloys and occasionally iron, but even into the fifteenth century, they thought of cast iron as “corrupt metal” due to the belief that the “liquefaction of iron ruined its properties” (Simpson, 69). Wrought iron, which was commonly used during this period, contains little to no carbon, whereas cast iron contains 2% or more carbon. This carbon makes cast iron brittle when cold and impossible to work when hot. In the fourteenth and fifteenth centuries, Europeans began making use of its lower melting temperature instead of throwing it away. Before casting iron, Europeans used only wrought iron, by heating and hammering it into the desired shapes (Sylvia, 4).
Early cauldron-makers either riveted the cauldrons together from multiple pieces or hammered them out from a flat sheet. One method introduced in the Viking age is seen in examples from the Mastermyr find. This method involves tabs being cut into the edges of the sheet and alternating them over and under the next sheet. Then, the entire joint is soldered down (Arwidsson, 38). The Mastermyr find includes two cauldrons hammered from copper alloys and a fragment of one in iron. These cauldrons have been repaired numerous times by attaching additional plates with many rivets, as shown in Figures 2 and 3 (10-11). The iron fragment indicates that the cauldron consisted of multiple sheets riveted together. This method becomes common in the Viking Age and can be seen on examples from Vendle and Valsgarde (24). The Anglo-Saxons also produced “considerable numbers of wrought iron cauldrons for domestic use” (Aitchison, 258). These cauldrons saw use for more than just cooking, as Figure 4 shows. Figure 5 illustrates the preparation for a 14th century feast including four large cauldrons. This helps to show the increased use and demand of large cauldrons. The only available cauldrons, however, came either from expensive bell metal, from the tedious labor of heating and hammering a large plate of metal, or from multiple sheets carefully riveted or soldered together to ensure a watertight vessel.
Cast iron metallurgy:
In the middle of the 14th century, the Black Death took one-third of the population. This major reduction of the workforce caused the mining industry to nearly stop except for the iron industry. Keeping the military equipped required that iron mining continue. In these new conditions, miners found it necessary to make their processes more efficient (Gregory, 44). The medieval Catalan furnace grew and the German Stuckofen furnace replaced it. This predecessor to the modern blast furnace used a bellows driven by a water wheel to produce higher temperatures. Cast iron resulted from this new, more efficient furnace. Additional refining produced wrought iron (Dennis, 10-13). Other developments included new systems for draining mines, which allowed for deeper mining, and increased use of water and animal power, where manpower was scarce (Gregory, 44). The demand for firearms and cannons pushed these advancements even harder such that between 1460 and 1530 production of iron increased fivefold (Rice, 14).
Around 1500, iron cauldrons began replacing bronze cauldrons (Tylecote, 107). Figures 6-8 show renaissance kitchens and their reliance on large metal pots. These pots vary in size and use. Some of them hang, some of them have three feet, and some have both features. Figure 9 illustrates the mechanical advantage needed to remove a large cauldron of partly riveted construction from its stand over the fire. Another large 16th century cauldron is shown in Figure 10, where the entire fire and floor have been raised up on a pedestal. Iron pots also found industrial uses. In 1580, Lazarus Ercker calls for the use of cast or forged iron pots, with the ability to disassemble them at the belly, for separating gold and quicksilver (Figure 11, Sisco and Smith, 110-111, 148). He describes these iron pots as “a good finger thick if they are to last long” and being able to hold around twenty pounds of material at a time (141). If, however, an iron pot cannot be made in short notice, earthenware can be used. This alludes to the fact that iron pots, particularly specialized ones, take a considerable time to make. Earthenware or glass flasks work, but the chance of them breaking is much greater and therefore the amount of quicksilver charged should be less (111). Ercker also claims that gold takes on a better color from the parting acid because of the iron (141).
In 1722, Reaumur stated that cast iron vessels are often not preferred over copper because of 3 reasons: they always look dirty, the thicker material takes longer to heat, and they break more readily (Sisco, 351). According to Reaumur, the primary problem, that of brittleness, can be minimized through annealing. Then the thickness may be reduced to allow for faster heating (351). Also, the rust from iron, unlike the rust from copper, is not objectionable. He assures the reader that “these vessels confer no taste upon the food cooked in them,” but those still worried can have their pots tinned (352). He then claims that if wrought iron worked easily, copper kitchen utensils would not exist. However, working such pieces in wrought iron “would be more expensive, because of the labor involved, than if it were made of silver and perhaps even gold (353-354). This is due to the nature of iron, which is more difficult to hammer into a hollow shape than copper, lead, gold, or silver.
Kitchens required cauldrons throughout history. Early on, these cauldrons represented a huge investment of time and money. The quickest way to ensure a watertight vessel involved casting. Due to the difficulty of casting such large items with tapered openings, metalsmiths created cauldrons using other techniques such as soldering and riveting. Copper alloys give an expensive pot that can burn up over time. Developments for casting iron in the Renaissance allowed for cheaper, longer lasting pots. Reaumur states, “It can be hoped that in the future almost the entire kitchen equipment will be made of cast iron” in order to save money (Sisco, 350-351). Eventually, iron-casting techniques replaced the time intensive construction of pots (Figure 12).
Figure 1: This 1st century B.C. Celtic cauldron from Gundstrup, in Denmark, had been disassembled and placed in a bog.
Figure 2: Metalsmiths crafted these copper alloy cauldrons from the Mastermyr find in the Viking Age.
Figure 3: The square tabs around the edges of the plates in these drawings of the cauldrons from Figure 2 show the “overlapped and stitched” joints. Also notice the number of times these cauldrons have been repaired.
Figure 4: This drawing from an 11th century Anglo-Saxon manuscript shows that cauldrons could also function as bathtubs for children.
Figure 5: This image from The Luttrell Psalter, c. 1340, shows the preparation for a feast including three large cauldrons over a fire and one being used as a mortar.
Figure 6: This 1507 kitchen shows both hanging and standing cauldrons.
Figure 7: This kitchen includes a wide range of cauldrons from 1542.
Figure 8: Kitchen implements from Venice, 1605 including cauldrons of various sizes.
Figure 9: An image showing the moving a cauldron of partly riveted construction, Venice, 1570
Figure 10: A huge, single-piece pot with lid from Venice, 1570.
Figure 11: Iron wires hold the special iron pot, parts H and K, together during use for separating gold and quicksilver.
Figure 12: A 1-gallon, 8-piece sand cast iron pot from my own collection. American, ca. 1750.
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Aitchison, Leslie. A History of Metals. New York: Interscience Publishers, Inc., 1960.
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Sisco, Anneliese Grunhaldt. Reaumur’s Memoirs on Steel and Iron: A Translation from the Original Printed in 1722. Illinois: The University of Chicago Press, 1956.
Sisco, Anneliese Grunhaldt and Cyril Stanley Smith. Lazerus Ercker’s Treatise of Ores and Assaying: Translated from the German Edition of 1580. Illinois: The University of Chicago Press, 1951.
Sylvia, J. Gerin. Cast Metals Technology. Massachusetts: Addison-Wesley Publishing Company, 1972.
Tylecote, R. F. A History of Metallurgy: second edition. London: The Institute of Materials, 1992.
2) Arwidsson, Greta and Gosta Berg. The Mastermyr Find: A Viking Age Tool Chest from Gotland. California: Larson Publishing Company, 1999. Page Pl. 11.
3) Arwidsson, Greta and Gosta Berg. The Mastermyr Find: A Viking Age Tool Chest from Gotland. California: Larson Publishing Company, 1999. Page Pl. 24.
4) Aitchison, Leslie. A History of Metals. New York: Interscience Publishers, Inc., 1960. Page 258.
5) Trevelyan, George Macaulay. Illustrated English Social History, Volume One: Chaucer's England and the Early Tudors. New York: Longmans, Green and Co., 1951. Page 16.
6) Unnamed woodcut, Johann Froschauer in Kuchenmeisterei, 1507 http://www.godecookery.com/
7) Hans Burgkmair, early 16th century http://www.geocities.com/katjaorlova/MedievalKitchenEquipment.htm
8) Orlin, LenaCowen. Elizabethan Households: An Anthology. Washington D.C.: The Folger Shakespeare Library, 1995. Page 105.
9) Il Cuoco Segreto Di Papa Pio V (The Private Chef of Pope Pius V), by Bartolomeo Scappi, Venice, 1570. http://www.pbm.com/~lindahl/food-art/
10) Il Cuoco Segreto Di Papa Pio V (The Private Chef of Pope Pius V), by Bartolomeo Scappi, Venice, 1570. http://www.pbm.com/~lindahl/food-art/
11) Sisco, Anneliese Grunhaldt and Cyril Stanley Smith (translators). Lazerus Ercker’s Treatise of Ores and Assaying: Translated from the German Edition of 1580. Illinois: The University of Chicago Press, 1951. Page 113.
12) Photo from my own collection.
Copyright Jacob Selmer 2004. All rights
Email: jselmer (AT) vt,edu http://filebox.vt.edu/users/jselmer/