Palm syrup is a type of sweet syrup extracted from the sap of several varieties of palm trees, including coconut palms, date palms, sugar palms, and palmyra palms. This food is used in Southeast Asian cooking, especially in desserts, and it can also be distilled to produce various alcohols, such as arrack, a fiery liquor similar to rum. Many Asian markets carry palm syrup, and it can also be purchased from specialty purveyors.
In order to make palm syrup, producers first have to collect the sap of palm trees. Agile workers are sent up the trunks of palm trees during certain times of the year to cut depressions in the crown of the palm tree and position collecting buckets beneath pipes leading from the depressions. As sap wells up and drips down the pipes, it is gathered in the collection bucket; once the bucket is full, it can be taken away for processing.
The sap is boiled down much like sugarcane juice to produce palm sugar and syrup. The syrup is extremely dense, like molasses, and it tends to be a very dark brown. It is also incredibly rich and very sweet, making it ideal for many desserts. The thick substance is extremely sticky as well.
Palm syrup is typically sold in bottles or tins, and it will tend to thicken and crystallize over time. It is most typically used in sweet foods like desserts, breads, pastries, and puddings, and it may be drizzled over various foods or mixed in as the food is prepared. Palm syrup can also be used to temper the flavors of spicy curries and other Southeast Asian dishes, adding its rich, molasses-like flavor to the food.
If you have a recipe which calls for palm syrup and you have trouble obtaining it, there are a number of options you can use. Molasses makes a decent replacement for this syrup, since it has a similar consistency and flavor. You can also use palm sugar to make syrup: melt the sugar and strain it to remove chunks and impurities, leaving the sweet, thick syrup behind. Be careful when doing this, as hot sugar can feel like napalm if it lands on exposed skin.