We’ve been waiting a year to make some sương sâm (vine jelly). Yes, it took a year to nurture and grow this tropical vine in Michigan and harvest enough leaves for a few experiments. Sương sâm is a refreshing snack for a hot afternoon consisting of wobbling, jiggling blocks of fragrant leafy jelly served with ice and simple syrup. Sương sâm is available in the States in cans but if we wanted to explore its applications we needed the leaves. We were very excited to finally try our hands at making sương sâm from scratch. We also created watermelon flavored sương sâm, combining two refreshing summer snacks for unprecedented cooling power 😛
Sương sâm can be made from the leaves of Tiliacora triandra or Cissampelos pareira (aka sương sâm rừng). I think we have the latter. We weren’t sure if our vine would survive the lack of sunlight during the winter months, but it did, and it’s now flourishing and climbing all over my two-level hanging garden.
The vines look delicate but they are tough almost like fishing lines. To make sương sâm, we harvested the leaves only by gripping the vine and running our fingers along from bottom to top, stripping the leaves off along the way.
We washed 7 grams of leaves, let them drip dry, then crushed or blended them in 50 ml of liquid. Traditionally, sương sâm is made by rubbing and crushing the leaves by hand while submerged in water (the leaves and hand, not the person). We’ve read that sương sâm will not gel if the leaves are processed by a blender because the spinning blades of modern technology would destroy the gelling agent. Thus, we set up our first experiment to reproduce that observation.
For the experiment above, we added more water than stated and found that sương sâm formed a gel but lost water over time (synaeresis). For the purpose of the experiment, the results were clear – blending did not prevent formation of a gel. However, blending had to be thorough, and whatever is left after straining the juice can be squeezed to improve yield of leaf extract. We think failures associated with blending were due to incomplete disruption of leaf structure, not destruction of gelling agent, whatever that is.
With the processing question addressed, we moved on to playing with flavors. We wanted to use fruit juices instead of water but we also read that sugar should not be mixed with leaf extract. Thus, the second experiment replaced water with sugar water or watermelon juice. Watermelon was blended and strained.
We used less water this time and checked on the sương sâm an hour after processing. No signs of syneresis. The extract/gel was so richly green that addition of red watermelon juice did not yield the feared red-green color combination.
This time, conventional wisdom was right. The sugared yielded a gel that was too soft and sticky to be cut into separate cubes. We ended up with a green blob. The watermelon juice sương sâm did form a very nice gel that could be cut into separate trapezoidal prisms just like traditional sương sâm. The blob had a very strong, almost bitterly leafy taste that couldn’t be balanced out by the sugar we originally added. More sugar would have been necessary but that would make this drink too sweet to be refreshing. Watermelon juice sương sâm had a nice subtle hint of watermelon that counterbalanced the leafy taste. It was a pleasant experience to be able to eat chilled sương sâm trapezoidal prisms straight without added sugar.
We were so glad to be able to make sương sâm from scratch. I loved getting a glass of sương sâm made by my cousins from vines gathered at the edge of the jungle abutting my grandparents’ farm. Being able to recreate that experience with homegrown vine was immensely satisfying.
It will be a few more months before we can make more but our minds are already preparing the possibilities. There are so many fruits and other flavors we want to try, like lychee or lilac honey. We also can’t wait to play with sương sâm the way we played with other hydrocolloids.