Make the pear puree. In a small saucepan, heat diced pear, lemon juice, honey, and water over low heat. Gently simmer until pear is softened, about 10 minutes. Add more water if necessary to prevent pear from sticking. Remove from heat and let cool for at least 20 minutes. Puree in a blender until smooth.
Add 1 tsp elderberry syrup and 1 oz pear puree to the bottom of each glass. Stir to combine.
Top with kombucha. Stir and garnish with thyme (optional).
Pear puree can be stored in the refrigerator for up to 5 days.