Jordan Valley in Islamic era: Hub of sugar production, advanced techniques

AMMAN — The Jordan Valley was known in Islamic times as a hub for sugar production. The most detailed historical account is written by Nuwayri (1279-1333) on the production of the Egyptian city of Qus.

The archaeological remains in the Jordan Valley and the more fragmentary historical accounts on the sugar production in this part of Bilad ash-Sham agree with the description of Nuwayri and show the process of sugar production was very similar if not the same.

Numayri states that the production process started in December when the cane was harvested and brought to the ma’sarah, said Eva Kaptijn from Leiden University, adding that ma’sarah is the Arabic word used to describe a sugar production centre located within the cane fields where the cane was transformed into raw sugar.

"Another name for this type of sugar production centre is tahun, meaning mill or grinder, e.g. Tell Tahunah or Tawahin es-Sukkar. It is different from a matbakh, which only denotes sugar refineries in a city," said Kaptijn.

She added that in the Matbakh the raw sugar produced in the ma’sarah was purified through additional boiling into the finished product, i.e. pure sugar. After harvesting the cane was brought to the refinery where the roots and top were cut off.

"Nuwayri writes that this was done on wooden tables with grooves by great knives 2/3 ell long and 1/3 ell wide. There is no archaeological evidence for this activity. The tops were kept separate and later manufactured like the sugar cane into syrup of poorer quality referred to as khabiyah," Kaptijn noted.

She added that the defoliating and cutting off of the roots is today often already done in the field.

The waste is then left and burnt together with the stubble. Nuwayri does not mention where and when defoliation occurred, but it likely happened at the same time as the roots and top were removed. If defoliating indeed occurred at the refinery the waste may well have been dried and used as fuel in the refinery.

No archaeological evidence for this practice has been found, although charred remains of the grass family that might belong to sugar cane have been reported for Horbat, Kaptijn said.

She noted that a lot of fuel will, however, have been needed for the boiling of the sugar and the firing of sugar pottery and this will likely have been a scarce commodity in naturally dry and heavily cultivated areas like the Jordan Valley.

Animal dung is a common and well-attested source of fuel, e.g. at Iron Age Deir ‘Alla. Given the great need for fertiliser in sugar cane cultivation it seems very probable that most, if not all of the dung, was spread over the fields as manure. It is, therefore, likely that all suitable waste products from the sugar cane were utilised as fuel, Kaptijn highlighted.

 When the tops and roots were removed and the cane was cleaned, it was carried to another area where it was chopped up and brought to the mill to be crushed, she continued adding that scholar Nuwayri writes that the mills of Qus were driven by bovines, whereas archaeology shows that most Levantine mills were powered by water.

"The millstones discovered in excavations are all of the so-called edge-runner type consisting of a large lower millstone on which a smaller wheel-shaped stone ran vertically in circles. For example, at Tawahin es-Sukkar in the Ghor es-Safi both stones have been found in situ," Kaptijn said.

The crushed cane was put in baskets and put under a press to remove the remaining juice. No traces of presses have been found in the Jordan Valley, Kaptijn pointed out, adding that this lack of presses might be explained by the presence of water-powered mills.

This made longer and harder pressing of the cane easy and less labour intensive than the additional use of smaller man or animal powered presses. The juice from both pressings was mixed, sieved and brought to the boiling area of the refinery.

Nuwayri states that for one millstone eight small boilers and one large boiler were needed and the fibrous waste product of the crushing is today called bagasse, Kaptijn said.

Moreover, in modern sugar cane production it is often used as fuel in a dried form. Apart from a single charred fragment discovered in the ash of the refinery at Horbat Manot that resembles a piece of cane but could only be identified as a member of the graminae family, there are no indications for such a use of bagasse in the Mamluk period.  According to Kaptijn, it might also have been used as animal fodder.

"The strained juice was boiled until it had reduced to a thick syrup. The thickened syrup was then poured through a woollen cloth and boiled a second time. The thick juice is now called mahlab, which translates as honey. This syrup was brought to the ‘house of the pouring’ where it was poured into the sugar moulds discovered so abundantly in the survey," said Kaptijn.

She stressed that the moulds were brought to a separate drying area in the "house of the pouring" and placed in or on top of long benches.

"Underneath each mould a jar was placed, in which the remaining liquid dripped. This jar was called qadus by Nuwayri and is what archaeologists call the syrup jar. The sugar mould is said to have three holes in its base that were plugged by pieces of cane," she said.

"The southern Levantine moulds have only one central hole in their base. In one of the excavated rooms at Tell ‘AbūSarbūt a bench with five sugar pots inserted in it has been found," Kaptijn underlined.

During this time the moulds were occasionally refilled until they remained completely full. At this stage the sugar moulds were moved, as Nuwayri puts it, "from the house of the pouring to the covered house".

It probably took some time before the sugar had completely crystallised. Once this had taken place, the sugar was referred to as qand. The qand was removed from the moulds, a process during which many moulds broke as is evidenced in archaeology, Kaptijn underlined.

 She added that the sugar cones were brought back to the boiling room dissolved in a blend of water and milk and were boiled again producing a white sugar and syrup.

"There is no evidence of syrup being traded; it was probably consumed locally. Another product that was only locally used was the so-called khabiyah syrup. This was the product of the crushing and boiling of the tops of the cane. The sucrose quantity was much lower and the resulting syrup was of poor quality. There are no precise statements as to how long this process of sugar production lasted," Kaptijn said, noting thatMakrisi describes that the sugar from Qus was shipped to the matbakh of Fustat at the end of May and in June.

At this time the entire refining process had, therefore, finished. The decreasing sugar content necessitated the starting of the production process immediately after the harvest.

 Once the cane had been crushed and boiled the sucrose degradation was stopped and the manufacturing process slowed down. "The crystallisation and drying of the sugar probably took a considerable amount of time as is indicated in historical sources. It is furthermore likely that the harvest was episodic and lasted for some time," Kaptijn underscored.