1. Cut the watermelon and remove the red flesh. Peel the green outer skin, keeping only the firm white part of the rind. Slice into small rectangles or diamond-shaped pieces.
2. Place the pieces in a large bowl, cover with water, and add the food-grade lime. Stir to dissolve and let them soak for 2–3 hours, stirring occasionally.
3. Rinse the rind pieces thoroughly. Transfer them to a bowl of clean water with the juice of 2 lemons and let sit for 1 hour. Drain and place them in a pot with enough water to cover.
4. Bring to a boil, then lower the heat and simmer for 20 minutes. Let cool and strain.
5. Return the rind to the pot, add the sugar and 1 liter of water, stir, and bring to a boil. Reduce the heat and simmer for 20 minutes.
6. Remove from heat and let sit overnight. The next day, bring to a boil again, then simmer for another 20 minutes.
7. On the third day, repeat the boiling process, adding the scented geranium. Simmer for 20 more minutes or until the syrup thickens.
8. Add the juice of the remaining lemon and the almonds. Stir and let cool. If desired, add rose syrup or food coloring for a pink hue.
9. Transfer the sweet preserve to sterilized, airtight jars and store in a cool place. Once opened, keep refrigerated.
10. To sterilize jars:
11. Wash jars and lids thoroughly. Preheat the oven to 110°C. Place jars upright on a tray with a clean towel or wire rack and heat for 10–15 minutes. Boil lids separately for 5 minutes and let them dry on a clean towel. You may also use a dishwasher with a sterilizing setting.

TIP

Food-grade lime (calcium hydroxide) is traditionally used in preserves to firm up fruit rinds. It’s also the main ingredient in some antacids.