I had never had a Rhubarb in a drink until I went to visit my cousins in Calgary. One taste and we were blown away. I converted her recipe to make it not only refined sugar free, but also non alcoholic. You can substitute liquid stevia or local raw honey for the maple syrup. I have converted even non rhubarb lovers with this drink. What's so wonderful about this drink too is that the rhubarb really shines. It is not hidden by the citrus. If you are looking for a way to use up an abundance of rhubarb without making sweets, this is a fabulous choice. You can juice the rhubarb and freeze it in glass jars (just leave space at the top of the jars) and then make this later in the year. This is best made with a Nut Milk bag. I have made it with both a nut milk bag and a cheesecloth. The former is much faster and results in much more juice being extracted. However you can certainly use a cheesecloth. You will just need to give the rhubarb ample time to allow its juices to come out.
Chop rhubarb in a food processor, pulsing until it is finely chopped. Line a strainer with a nutmilk bag or cheesecloth. Place it over a large glass bowl. Place the rhubarb mash inside the bag/cloth and gently knead out the juices. You may want to allow the rhubarb to drip slowly to render its juices. However kneading and squeezing out the juice will still be necessary. You'll be amazed at just how much juice comes out!
Once you have gotten 4 cups(1 liter) of juice from the rhubarb, pour juice into a medium saucepan. Add the orange and lemon juice, then add the maple syrup or sweetener of choice. Warm the mixture over medium heat for about 10 minutes to allow the sweetener to dissolve. Place the juice in a glass jar and allow to cool.
Serve over ice with about 1/3 rhubarb mixture to 2/3 sparkling water or club soda in a glass. Enjoy!!!