The idea of making a rhubarb cordial comes from The Joy of Jams, Jellies, and Other Sweet Preserves and Tigress in a Jam. Cordials are sweet and delicious. They are meant to be diluted in pop, alcohol or whatever you like. I wanted to make something a little less sweet to use in Popsicles for the little ones, so I made a rhubarb juice and here is my recipe:
Canned Rhubarb Juice
Adapted from The Joy of Jams, Jellies, and Other Sweet Preserves.
Steam juicer or jelly bag
Sugar [add 1/2 cup per 1 L of juice]
Chop the rhubarb. Juice the rhubarb according to your steam juicer’s directions. You could also extract the juice using a jelly bag and following the directions at Tigress in a Jam. For each 1L of rhubarb juice add 1/2 cup of sugar, you can add more or less sugar depending on your preference and the tartness of the rhubarb. Stir to dissolve the sugar. Bring the mixture to a boil and boil for 1 minute.
Pour the juice into sterilized quart mason jars, leaving a 1/4 inch headspace. Top with lids and place into a boiling water bath canner. Process for 10 minutes, or adjust the amount of time according to your altitude.