Kitchenalia: Roman Mortarium

Most people are probably familiar with a pestle and mortar. They come in many different guises: board-like, bowl-shaped or, more traditionally, cup-shaped. There are many different sizes, and the mortars, at least, can be made of wood, stone, bronze, brass or even cast iron.

All, however, are used for grinding, pounding, mixing or blending ingredients, typically for culinary or medicinal purposes. Perhaps you have one in your kitchen, but do you use it? And what of its history?

In "Kitchenalia" we introduce objects from different historical periods, discover a bit about their history and find out how each was made. We look at how, through our practical experiments, we have learnt to best use them, and we have even included some recipes for you to try at home.

Today's object is an iconic piece of Roman kitchenware: the mortarium. You will be unsurprised to discover the English word “mortar” is derived from classical Latin where mortarium means, among several other usages, "a receptacle for pounding" or "a product of grinding or pounding". The series of examples pictured above are more reminiscent of Mediæval types ideal for grinding spices, herbs and plants, and for mixing medicinal powders.

Roman tastes in food favoured the use of sauces, relishes and subtly blended herbs and spices. Such ingredients often needed to be ground or puréed, and a strong mixing-bowl with a grit-roughened interior was, therefore, an essential kitchen utensil. Those shown above are replicas of Roman mortaria (sing. mortarium) copying the form and function of a plethora of examples recovered from across the Roman world.

Adoption in Britannia  Mortaria are a uniquely Roman utensil, perhaps being one of only a handful of things the Romans truly innovated. Vessels recognizable as mortaria were produced in Italy from at least the 3rd-century BC. Together with other Italian earthenware and coarse wares, amphorae for example, these mortaria were exported all around the Mediterranean. Many of the surviving artefacts have stamps and marks impressed into the clay which have aided research into this widespread trade. Such stamps were the abbreviated names, often of the individual potter, and symbols impressed on to the handles, rims or necks of, say, amphorae or other wares. In the case of amphorae we also have tituli picti were inscriptions painted onto different parts of amphorae after firing. Together, the stamps and inscriptions provide valuable information about the involvement of individuals and places in the production, transport and supply of foodstuffs or in this case kitchenware across the Roman Empire.

From tracing the movement of mortaria, some of the earliest examples in the archaeological record appear in Britain before the Roman conquest. From this one can infer that there were people, either native Britons or immigrants, who imported and enjoyed Roman-style cuisine [1] that benefitted from the use of Roman-style kitchenware. Thus the mortaria dating to the later Iron Age discovered at sites located predominantly in the south-east were continental imports.

The scale of this trade was initially low but after AD 43, both imported and locally made mortaria became increasingly common in Britain. Two major manufacturing centres began to dominate the British market. One was situated south of Verulamium (St Albans) and the other in either Gallia Belgica, an area we would think of as the area covered today by Belgium, Luxemburg and northern France. By the later first century, imports had all but ceased, with only very low numbers of Gaulish mortaria represented after AD 100. Moreover, as time moved on, production was no longer confined to southeast Britain, with many other potters in the Midlands and further north producing and distributing mortaria albeit alongside the still-dominant south-eastern production centres.

As the Romans slowly but steadily took control of the new province of Britannia, the army became instrumental in spreading mortaria and many other Roman introductions, like olive oil and wine, across Britain. From the archaeological record, by the second century AD, mortaria had evidently become increasingly popular. It is evident from the distribution of finds that these ubiquitous objects had spread from predominantly urban and military settings to more rural settlements.

Form  The replicas we use represent the form most likely seen in museum displays across Britain and, indeed, elsewhere in the area covered by the Roman empire. But the earliest mortaria found in Britain were straight-sided, usually without a spout, but with a roughened surface created by the potter incising lines into the interior before firing. By the mid-first century, however, it seems the early version had become obsolete being replaced by the classic mortarium we see represented above right. Each has a well-defined rim and flange, with coarse sand or grit embedded into the bowl’s interior to replace the internal scoring.

Function  According our Roman sources, such as Apicius and Columella who both refer to a mortarium in the context of cooking, mortaria were used to grind, pound and mix together a range of ingredients. These included, but not limited to, herbs, spices, meat, oil, fish sauce and wine, in order to prepare dishes such as rissoles, sausages and moretum - a kind of cheese.

Our knowledge of what foods mortaria were used to process is guided by the scientific analysis of the organic residues on surviving vessels or fragments thereof. Even though mortaria are hardened pieces of kiln-fired pottery, the clay itself remains porous such that liquids, oils and fats can seep into and remain trapped in the material. A study[2] from 2011 has shown that, as well as plant material (vegetables, herbs, spices, etc.), many of the mortaria excavated from across Britain also had the residue of animal fats and dairy products present. In one example from Stanwick in the north of England, the dairy residue was identified as butter. It seems butter was still used by local Britons in preference to imported olive oil. Significantly, it is highly unlikely that these mortaria were used to make butter or cheese. The shape of the mortarium does not lend itself well to the lengthy churning of the milk until it becomes butter. As far as cheesemaking is concerned, the roughened surface simply cannot be kept clean enough to avoid spoiling the end result. This, however, does not preclude the processing of cheese in the mortarium as an ingredient in a dish.

Analysis and comparison of residues in mortaria and cooking pots provide clues to the diet in Roman-Britain. But the science lends weight to the argument that mortaria were not used for the actual cooking. From our practical experiments, mortaria are better suited as "food processors" and not cook pots. They are, as the name suggests, ideal for the grinding, pounding and mixing of ingredients to recreate flavoursome Roman recipes.

Notes:

1. In much the same way as the British aristocrats who eagerly imported wine from the Roman world.
2. Lucy J.E. Cramp, L.J.E, Evershed, R.P. & Eckardt, H (2011), "What was a mortarium used for? Organic residues and cultural change in Iron Age and Roman Britain", Antiquity 85.

Our thanks to Jim and Emma Newboult of Trinity Court Potteries who made our replica mortarium.