First we are going to make a basil simple syrup. Combine the 1 cup sugar and 1 cup water in a small sauce pan and warm it over a medium-high heat–this makes 1 1/4 cup. Bring it to a simmer so that the sugar is fully dissolved. Remove it from the burner and stir in the 5 fresh basil leaves. Fresh basil should be added at the end of the cooking process. Prolonged exposure to heat will cause the herb’s volatile oils to dissipate.
Once the simple syrup has cooled to room temperature, strain out the basil leaves and transfer it to the refrigerator to cool.
NOTE: Honestly, basil simple syrup can be great in lemonade or over ice cream, the possibilities are endless. So you might want to make more than just 1 1/4 cup. The general rule for simple syrup is that you need 75% of both sugar and water for whatever measurement you want. For example, if you want 1 cup of simple syrup, you’ll need about 3/4 cup of both sugar and water to make that. It all scales from there.
Now juice both white grapefruits and measure out 1 1/2 cup. I like the texture of the pulp in the popsicle so I am going to add it back in after juicing it. If you want to do this too, just pick out any of the seeds found in the pulp and then put it and the juice in a food processor and process for about a minute. This will break up any large strands that might exist.
Next we are going to supreme the ruby red grapefruits. We do this because we want chunks of the fruit throughout the popsicle (the deep pink mixed in with the off-white looks amazing, right?) but we do not want any of the white pith in our pop.
So first trim the top and bottom off of the fruit, all the way to the flesh. Now using a paring knife, peel off the outer peel. It is okay if some of the pith remains behind. You don’t have to be super anal retentive about it. You can get the remaining pith after the peel is fully removed.
Now you are going to cut out the fruity segments by slicing down alongside the membrane and cutting towards the center. Imagine you are serving a slice of pie. Repeat this until the whole fruit is done. Here is a fun way to use up those grapefruit peels.
Chop the ruby red grapefruit slices into fairly small chunks.
Combine the 1 1/2 cup white grapefruit juice, the 1 1/4 cup basil simple syrup and the 1/4 cup vodka into a large measuring cup. Mix well.
Divide the boozy grapefruit mixture amongst the popsicle molds and then add in the chunks of ruby red grapefruit to each mold.
Add the popsicle sticks.
Freeze for at least 7 to 10 hours as you want these pops to be rock hard.