In a spacious pot, combine figs, sugar, lemon slices, and strawberry gelatin. Allow the mixture to sit for one hour. Then, bring it to a boil and cook on medium heat, stirring regularly to avoid scorching. Continue cooking until the foam subsides, and the preserves have thickened, which typically takes around 25 to 40 minutes. This method ensures that the jam is perfectly cooked and has a thick consistency while preventing any burning.

To ensure proper hygiene, immerse the jars and lids in boiling water for a minimum of 5 minutes. Once sterilized, carefully fill the hot jars with the fig preserves, leaving approximately 1/4 inch of space at the top. After filling, run a knife or thin spatula along the inner sides of the jars to eliminate any trapped air bubbles. To remove any residual food particles, gently wipe the jar rims using a damp paper towel. Finally, seal the jars by placing the lids on top and securing them with rings.

Place a rack in the bottom of a large stockpot and fill halfway with water. Bring to a boil and lower jars into the boiling water using a holder. Leave a 2-inch space between the jars. Pour in more boiling water if necessary to bring the water level to at least 1 inch above the tops of the jars. Bring the water to a rolling boil, cover the pot, and process for 10 minutes.

Take out the jars from the stockpot and position them on a cloth-covered or wooden surface, keeping a few inches of space between each jar, until they cool down. Once the jars have cooled, use your finger to press down on the top of each lid, ensuring that it is securely sealed (with no movement up or down). Keep the jars in a cool and dark place, and refrain from opening them for at least 2 days.