Grapes or Raisins? an Early Bronze Age Larder under the Microscope. (Method)
Cartwright, Caroline R., Antiquity
Tell es-Sa'idiyeh, a large double mound, is prominently situated in the central part of the fertile alluvial plain of the Jordan valley, about 1.8 km east of the River Jordan. The Lower and Upper Tells span the Early Bronze Age through the Persian Period--only the Middle Bronze Age is absent. Excavations of the tell since 1964 have revealed extensive architectural remains of different functions (Tubb et al. 1997). On the Lower Tell, Late Bronze Age graves cover much of the extensive underlying Early Bronze Age domestic and industrial architectural complexes. One of these complexes revealed a small room containing a remarkable assemblage of ceramic store-jars, platters, small bowls, juglets and a jug with an internal strainer. Also present were flint blades, bone points, beads and a copper alloy axe head.
The sudden conflagration of the room had preserved these artefacts in close association with a significant assemblage of charred archaeobotanical material. Standard techniques of optical microscopy were used to identify the charred plant remains, using comparisons with modern reference material of wild and cultivated taxa. However, the condition of some of the fruits raised the question of whether they had simply been burnt in the fire or were already stored dry. To address this question a series of experimental charrings were carried out on modern specimens in a laboratory kiln in an attempt to replicate the archaeological material. Standard techniques of scanning electron microscopy were then used to examine and compare the replicated specimens with the originals.
The charred archaeobotanical assemblage consisted of cereal remains, fruits, legumes and weeds. Cereals included wheat (Triticum sp.) and barley (Hordeum sp.). The pulses consisted of lentils (Lens sp.), chickpeas (Cicer sp.) and faba bean (Vicia faba). Weed seeds, associated with cultivation, were also present in some juglets. Cultivated fruits included grapes (Vitis vinifera), figs (Ficus sp.), a pomegranate (Punica granatum) and some olive pits (Olea europaea). Wild fruits from hawthorn (Crataegus sp.) and Christ's thorn (Ziziphus spina-christi) trees were present. Small nutlets of wild pistachio (Pistacia sp.) and acorns (Quercus sp.) were recovered from two of the juglets. One of the small bowls contained flower buds of caper (Capparis spinosa), the first such find for the region and the period.
Evidence for preservation
Charred grape pips were found, but unusually, whole grapes were also present. Despite having been charred, they were almost perfectly round with little wrinkling of the skin (Figure 1). At first, the grapes were assumed to have been burnt while fresh. However, experimental charring of modern fresh grapes revealed that it was impossible to replicate the condition and appearance of the archaeological material by charring fresh grapes. In all cases, the grapes remained uncharred and mostly disintegrated to pulp; only the pips and stems would char. The only method of successfully replicating the archaeological specimens was to char raisins. After charring a batch in the kiln for 50 minutes at 350 degrees, the raisins appeared to 're-inflate'. These replicated their archaeological counterparts very closely in size, form and surface appearance. This does not prove incontrovertibly that the archaeological remains were raisins rather than fresh grapes, but the evidence points strongly in that direction. Further support for this interpretation was given after examination of the archaeological specimens under the scanning electron microscope. The fruit's surface showed many crystalline features (Figure 2), possibly produced through sun drying which allowed fruit sugars to crystallise to the surface, thus preserving the fruit.
[FIGURE 1 & 2 OMITTED]
Charred fig seeds were found, but, more significantly, there were also specimens of charred whole figs and fig pulp. …