Working over a bowl cut all the fruit in half and remove the seeds. Then slice the mandarinequats, peels and all into ¼-inch strips allowing the peels, pulp, and juice to collect in the bowl. Repeat the process with the Meyer lemon, but slice its strips at 1/8-inch. Discard all seeds.Bring fruit, peels, juice, water and cinnamon sticks to a boil in a large saucepan. Cook for 5 minutes. Turn off heat, cover, and let cool. Refrigerate overnight.The next day uncover the citrus mixture, and bring to a simmer over medium-high heat. Cook until thickest peel is tender, about 20 minutes.
Add 3/4 cup sugar.and bring mixture to a boil, stirring often. Cook until it registers 220 degrees on a candy thermometer, about 20 minutes.
Remove the pan from the heat and let it cool about 15 minutes then transfer the marmalade to an airtight container.
Remove the cinnamon sticks pieces and cover, letting it come to completely cool at room temperature. Refrigerate overnight before serving. Marmalade will keep, covered and refrigerated, for up to 1 month.
