Combine, sugar, water, and jalapeno in a small pot over medium heat; cook until sugar dissolves and syrup begins to bubble, stirring frequently.
Reduce heat to medium low and cook for 5 minutes.
Remove from heat and allow to cool.
Strain syrup and transfer to an airtight container. Refrigerate until ready to use.
Prepare Paloma:
Cover the bottom of a saucer or other small dish with salt.
Wet glass edge with lime wedge.
Dip rim in salt.
Fill glass with ice, then add grapefruit juice, syrup, and tequila to glass.
Squeeze juice from second lime wedge into glass, then top with sparkling water.
Give cocktail a stir and serve. Enjoy!
Notes
*I used organic cane sugar, which is vegan. **For a milder syrup, remove seeds and membranes from the jalapeno or leave out the jalapeno altogether. For a spicier syrup, add additional jalapenos.