Kitchenalia: Roman Testum
Updated: Jul 21, 2022
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 a piece of Roman kitchenware that we know as the testum.
There are different types of ancient baking covers, sometimes referred to as 'portable ovens'. They are generally called either clibanus or testum, with both terms mentioned so frequently in Roman literary sources that there can be little doubt they were a fundamental element of the Roman kitchen at many levels of society . The former term, clibanus, is the more fashionable Latinised Greek word, while testum represents the Italian tradition for these ovens  and will be the convention we will use.
From practical experiments we and others  have undertaken with replicas, the testum seems cleverly designed to apply heat above and around the food being cooked. Indeed, written clues for this cooking technique are hinted at in the surviving collection of Roman recipes known as Apicius. In one recipe the fire’s embers are described as being '…above and below [the dish].' While the description does not tell us exactly how this may happen, we can imagine the dish must have been lidded for the fire to be on top of the food.
Further evidence may be inferred from the many Roman-era North African-ware lidded casseroles that would suit this technique. Examples have a small base dish that sat in the embers on the hearth, and curved walls to allow embers to be pushed beneath the dish. Today we would call this earthenware pot a “tagine”, so rather than an oven it might be more accurate calling the testum a tagine.
The version we use (pictured right) is slightly different in that it is essentially a one-piece cover with straight-walled sides, an upward curving outer rim and a central vent that can be plugged. Allied with the description in Apicius, the testum's shape - its form - gives a clue to how it might have been used - its function.
The Romans typically cooked on a flat, stone topped plinth upon which one or more charcoal or wood fires were lit. Many examples of these "cookers" (pictured right) can be seen in the archaeological sites of Pompeii and Herculaneum in Italy. From practical experience, cooking pots can be heated next to the hot fire, placed in or be surrounded by its embers or coals, or set above the fire on iron trivets. By adjusting the vessel's height above the fire or the pot's proximity to the heat source, the cooking temperature can be easily regulated to boil, simmer or simply warm foods.
Unlike the version used by Sally Grainger in her blog post for the British Museum , our testum does not have a base dish and is thus more of a lid or cover. To use it you first have to rake clear a space in the hot coals. Remember the stone top will have been heated, so anything you now place in the cleared space will also be warmed from beneath.
So, let us say we place a dish containing chicken pieces on the stone top. It begins to warm from the radiated heat below. Having been gently warmed by the fire, to avoid thermal shock, the testum can be placed over the dish and the hot charcoal scrapped back against its side walls. The rim becomes important at this point as it allows hot coals to be placed on top as shown below.
With coals surrounding the testum and on top of it an intense heat can be generated inside. If a little liquid or a sauce had been added to the dish inside, then by keeping the sauce simmering consistently around the meat plenty of steam is generated which, in a similar way to a traditional tagine, gathers in the dome and falls back into the dish, preventing the meat from drying out.
The steam is trapped if the vent is plugged, but by removing the plug, excessive steam can be released. Moreover, a visual check on cooking progress can be made. Once the food is cooked, the hot cover can be carefully removed whereupon, rather cleverly, the rim acts to keep the embers away from the food.
According to Apicius a testum is ideal for roasting or pot roasting albeit rather small dishes. We have used our testum to bake meat, bread and cakes. Indeed, we have successfully produced a Roman form of 'cheesecake' we call 'libum'. The recipe is derived from the one recorded by Marcus Cato's in his book On Agriculture. In early Roman history, libum was sometimes a sacrificial cake offered to the spirits of the household . Equally, it was sometimes a farmhouse cake served hot or a delicate honeyed cake served at the end of an elaborate dinner . With the exception of Cato, all ancient authors associate libum with honey so that is the path we have chosen. Trust us, hot from the testum or oven, and smothered in honey, libum is absolutely delicious. Cenebus bene.
1. Cubberley, A., Lloyd, J., & Roberts, P. (1988), Testa and Clibani: The Baking Covers of Classical Italy, Papers of the British School at Rome 56, pp. 98-119, (accessed February 1st, 2021).
2. Grainger, S. (2013), From Parthian chicken to flat breads: experimenting with a Roman oven, British Museum Blog (accessed January 31st, 2021).
3. Dalby, A. & Grainger, S. (2012), The Classical Cookbook, The British Museum Press, p. 110.