1 tablespoon applesauce
1 cup water
2 cups sugar
Use a vegetable peeler to peel the grapefruit. Once you get all of the peel off (try to avoid getting any of the white pith), slice the peel into thin slices and then slice the bunch in half.
Desegment the rest of the grapefruit. Make sure to do this over a bowl so that you catch all of the juice. Pick out any seeds that fall into the bowl.
In a small saucepan, combine applesauce, peel, fruit pieces, and water and bring to a boil for 10 minutes. Reduce the heat to a simmer and simmer for about 30 minutes. In the meantime stick a small dish in the freezer. Stir in all of the sugar and continue stirring for 15 minutes.
Take the dish out of the freezer and place about a teaspoon of the marmalade onto the dish. After about a minute check the consistency of the blob. If the mixture wrinkles when you touch it, it's ready. Remove from heat and pour into a container.
Let cool and store in the fridge.
I'm not a huge marmalade fan, but I had a bunch of CSA grapefruits I hadn't yet touched so I decided to be creative. I've also never made jam before. The end result was pretty good. A little more bitter than orange marmalade, but I made it myself so it tasted better.
I suggest using only about 1 1/2 cups of sugar, instead of the 2 cups because this was a tad too sweet for my tastebuds.