Remove the skin of the rambutans and then slice the flesh of the rambutan away from the seed. I prefer to cut the rambutan flesh instead of peeling away because when peeled the outer hard shell of the seed can get stuck.
Start by blending the rambutan or lychee flesh until smooth with the lime juice. If necessary, add a dash of water to facilitate blending, but only if your blender is not powerful enough to handle the fruits on its own. It's okay if the mixture is a little bit lumpy / not fully smooth.
Once blended, transfer the rambutan or lychee mixture to a pot. Add the appropriate amount of sugar based on the weight of the fruit flesh. Stir well to ensure the sugar is evenly distributed throughout the mixture.
Place the pot on the stove and bring the mixture to a boil. Once it reaches boiling point, reduce the heat to a simmer. Let the mixture simmer for approximately 10-15 minutes, stirring regularly to prevent sticking or burning.
Complete a Jam Test to confirm if the jam is ready (refer to blog notes). Once the jam is ready, allow the jam to cool slightly before adding to a jar. When adding the jam to a jar, ensure that the jar is preheated to prevent any cracking. Run the jar under boiling water before filling it with the jam.