Line a colander or fine-mesh strainer with a triple layer of cheesecloth and place over a large bowl or measuring cup. Place yogurt in the colander, cover with plastic wrap (plastic should not touch yogurt), and refrigerate until 1¼ cups whey have drained from yogurt, at least 8 hours or up to 12 hours. Discard whey. (If more than 1¼ cups whey drains from yogurt, simply stir extra back into yogurt.)
Sprinkle gelatin over the orange juice in a small bowl and let sit until gelatin softens, about 5 minutes. Microwave until mixture is bubbling around edges and gelatin dissolves, about 30 seconds. Stir in orange zest and let cool for 5 minutes. In a large bowl, whisk together the sugar, syrup, salt, drained yogurt, and cooled orange juice–gelatin mixture until the sugar is completely dissolved. Cover and refrigerate (or place the bowl over an ice bath) until the yogurt mixture registers 40 degrees F or less.
Churn the yogurt mixture in an ice cream maker until the mixture resembles thick soft-serve frozen yogurt and registers about 21 degrees F, 25 to 35 minutes. Transfer the frozen yogurt to airtight container and freeze until firm, at least 2 hours, before serving.
Notes
Note: You may substitute light corn syrup for the Lyle's Golden Syrup.Nutritional values are based on one serving