Begin by thoroughly washing the mandarins and removing the fruit crown (calyx).

Place the washed mandarins in a suitably sized pot and cover them with cold water.

Set the pot on the stove over medium-high heat and bring the water to a boil. Once the water is boiling, let mandarins boil in water for 1 minute, then remove the pot from the heat.

Drain the water while keeping the mandarins in the pot. Cover them with cold water again and repeat the boil and drain process two more times.

For the final round of preparing the fruit, cover the mandarins with cold water and bring them to a boil.

Lower the heat to medium-low and continue boiling the mandarins in the water for 1 hour. Then, drain them and set aside to cool slightly for about 10 minutes.

Using an immersion blender or a regular mixer, carefully blend the mandarins until you achieve a homogeneous mixture.

Mix the sugar with the pectin. Then, combine the pectin-sugar mixture with freshly blended mandarins.

Place the pot back on the stove. Bring the jam mixture to a gentle boil over medium heat. Stir occasionally to ensure the sugar dissolves completely.

Once the mandarin jam mixture is boiling, reduce the heat to low and let it simmer uncovered for 7 minutes, stirring occasionally to prevent sticking and burning.

Perform a chilled plate test to check the jam's consistency and adjust if necessary.

Once satisfied, pour jam into the jars and process according to your preferred canning method.