The Sap, The Cold And The Clock: Why Nolen Gur Has A Three-Month Season

Come winter, a typical Bengali turns romantic about nolen gur. This fresh jaggery is made from the sap of the wild date palm (Phoenix sylvestris) and is usually available from mid-November to February.

The love comes in many versions. There is liquid jaggery, warm and fragrant. There are chhanagolla (cottage cheese balls) shaped in the freshest gur. If we are feeling indulgent, there is a thin, flaky paratha to go with a bowl of jhola (nolen) gur. For all that, I would still choose a crisp slice of toast with nolen gur.

Literature romanticised it too. In Bhalo Rey Bhalo, the pioneering Bengali writer and poet Sukumar Ray celebrates life’s many pleasures, from the fragrance of flowers to the cottony blooms of the shimul tree. Few of them, he suggests, can rival eating nolen gur with bread.

It belongs as much to memory as to the kitchen. But it has a constraint that sugar and many other sweeteners do not. It can only be made when the weather, the tree and the sap align. That gives Bengal a short winter window to make the most of it.

Why the window is so short

The window is set by temperature, the chemistry of the sap, and how quickly it can be harvested and processed before it ferments.

Fermentation is the clock. Fresh palm sap contains fermentable sugars, which microorganisms can begin converting into alcohol and organic acids. As fermentation progresses, the sap’s acidity, sweetness and other properties change, and so does its suitability for jaggery-making.

A 1988 study by T R Shamala and K R Sreekantiah, published in Food Microbiology, identified yeasts, including Saccharomyces cerevisiae, and several types of bacteria in freshly tapped wild date-palm sap. The researchers documented changes in microbial growth and in the production of ethanol, acids and esters during fermentation. Their findings help explain why freshly collected sap cannot be left standing for long before processing.

Cold buys time. Cooler winter conditions slow fermentation and give tappers a better chance of collecting usable sap. Once the weather warms, that window becomes harder to manage. The sap must be brought down early and processed promptly to preserve the qualities nolen gur needs.

Even within winter, the sap keeps changing. A 2015 study in the Indian Journal of Agricultural Sciences looked at this in Bengal itself. Dipak Girhepuje, S Mondal and P K Bandopadhyay of Bidhan Chandra Krishi Viswavidyalaya examined sap from 15-to-20-year-old trees in Haringhata block, Nadia district. They took separate samples between December and February across two seasons, 2012–13 and 2013–14.

Their findings:

• Total soluble solids, which indicate the concentration of dissolved substances, reached 14.33% in February.

• Total sugar rose from 11.37% in December to 12.50% in February.

• The sugar-to-acid ratio fell sharply, from 325.47 in January to 42.93 in February.

• Vitamin C declined from 18.75 mg per 100 ml in December to 13.75 mg in February.

• Alcohol content was highest in February.

So the sap does not stay chemically identical through winter. Its properties shift even within the traditional harvesting period.

How nolen gur is made

Before Kolkata’s sweet shops fill their trays with nolen gur sandesh, and before we get the first taste, a lot happens in villages across Bankura, Birbhum, Jhargram and Khejuri (Purba Medinipur).

The night a tree fills a pot. The process begins with the khejur gaach, or date palm. Traditional tappers, known as shiuli or siuli, make a controlled incision in the tree and fit a small bamboo channel to guide the sap into an earthen pot. The pot hangs overnight and collects the liquid that flows from the cut. In the hours before dawn, the tapper returns to the tree he climbed the previous evening and lowers the pot. The timing is essential, for the reasons above.

When the sap meets the fire. Freshly collected sap is not yet jaggery. It is filtered and heated in large pans so that water evaporates and the sugars concentrate. As the liquid thickens, its colour, viscosity and flavour change. The result may be jhola gur, a pourable jaggery, or patali gur, the solid variety used in sweets.

A 2009 study in the Journal of Food Engineering examined this transformation. P V K Jagannadha Rao, Madhusweta Das and S K Das studied how boiling changes the physical properties of sugarcane, palmyra-palm and date-palm juices. As dissolved solids increased, the juices became more viscous and their boiling temperatures rose. For date-palm juice, the changes were particularly pronounced in the final stage of concentration.

For sweet-makers, this means the quality of the finished jaggery depends on both the sap they receive and how carefully it is processed.

More than a seasonal sweet

Nolen gur connects Bengal’s winter landscape to its food traditions and rural livelihoods. It gives pithe, payesh and sandesh their seasonal character. It also supports the people whose knowledge of trees, tapping and boiling makes it possible.

That dependence on winter has consequences. As warmer weather threatens to shorten the tapping season, producers face declining yields, and sweet-makers face uncertain supplies of an ingredient central to the winter table. A shorter winter can mean fewer litres of sap, less jaggery to sell and a smaller income from months of specialised work.

Preserving nolen gur therefore means looking beyond the sweet shops. It means understanding how changing temperatures affect the date palm’s harvesting cycle, documenting changes in sap yields over time, and supporting the tappers whose livelihoods rest on a narrow winter window. As climate change reshapes seasonal patterns, the challenge is to safeguard the ecological conditions and traditional knowledge that make nolen gur possible.

Sources:

‘Microbiological and biochemical studies on traditional Indian palm wine fermentation’: By T.R Shamala, K.R Sreekantiah, Published on 20 October 2004

‘Changes in physico-chemical properties of wild date palm (Phoenix sylvestris) sap over its peak production period’: Dipak Girhepuje, S Mondal and P K Bandopadhyay, Published on 8 July 2015

‘Bhalo re Bhalo’: Sukumar Ray

Disclaimer : This story is auto aggregated by a computer programme and has not been created or edited by DOWNTHENEWS. Publisher: thebetterindia.com