I found some blood oranges at Wal-Mart of all places, and I couldn't resist picking up a bag. It's been a while since I had a good sanguinella, though if I remember right, San Pellegrino has a good one. Update: Yes, I found some in cans at Wegman's, I'll have to add that to the taste test mentioned below.
So here we have one orange juiced and three more ready to go. I peeled these, sectioned them and put them in a blender after removing as much pith as I could. That may or may not have been a good idea. That bitter pith flavor still comes through a little bit, perhaps it's from the pulp. Makes you feel like you're eating a fresh orange, though, so if that's what you're going for, then great!
From these three oranges, I ended up with about 1 cup of juice. I was a little shy of the 1 cup mark, so I made up the difference with lemon juice to add some extra tartness.
After squeezing the juice through a clean juicer bag to separate out the pulp, I added that to some invert sugar syrup scaled for a gallon of finished soda. (Invert Sugar Recipe, thanks to Chef Eddy). Add the juice to the hot syurp to kill any natural yeasts and then add that to your carbonated water. Done.
1 cup Blood Orange Juice mixed with Lemon Juice for added tartness, ratio depends on desired tartness
2 cups sugar, inverted
Top up to 1 gallon with carbonated water.
I'm fairly happy with how this turned out, it could have used the citric acid that I wanted to add, but didn't. I have some Blood Orange Monin syrup to compare it to, and I'm waiting for the right time to do a side by side taste test.
When I bottled this, I was very impressed at first with the color of the two syrups. Pardon the blurry photo, but right is my syrup and left is Monin's syrup. Monin's is a little darker, but not by much.
Here's a clearer photo, monin is the bottle at left and the one with the funnel behind.
Once filled the Monin was still a bit darker, not to mention clearer than mine. Those natural colors do dilute quite readily, apparently.
As far as taste goes, I have yet to really taste them side by side. I have to get my hands on the San Pellegrino. But it does seem like the Monin has a "brighter" orange flavor. Mine is a bit more "dull" and ever so slightly bitter, like biting into an actual orange, not just sipping the juice. Still pretty good if you like oranges.
Update: It's taken me so long to post this, I'm not sure that you can still get blood oranges in the store anymore, they're a bit out of season. But theoretically, this recipe should work well with any citrus juices. I have some meyer lemons that are aching to be used in a beverage that I'm planning on trying out rather soon. We'll see if the recipe still holds up there.