Crabapple Juice

Rinse the crabapples thoroughly under cool water and remove any remaining stems. Discard any bruised or spoiled fruit.
Place the crabapples in a large pot and add 8 cups of cold water. Bring to a boil over high heat, then reduce to a simmer.
Simmer uncovered for 30 minutes, stirring occasionally, until the crabapples are soft and the liquid turns a deep pink or red.
Line a fine-mesh strainer with cheesecloth and set it over a large bowl. Carefully pour the cooked crabapples and liquid into the strainer. Let drain for 1 hour without pressing to ensure clear juice.
Return the strained juice to the pot and stir in the sugar, cinnamon stick (if using), and lemon juice. Heat over medium-low heat until the sugar dissolves, about 5 minutes.
Remove from heat and let cool to room temperature. Discard the cinnamon stick. Pour the juice into a clean pitcher or bottles and refrigerate until chilled. Serve over ice.