Wash and prep the rhubarb, chopping the stalks into chunks about 3 cm (1 inch).
Freeze for 4 to 6 hours or over night, until frozen solid.
In a large pot, mix together the Clearjel, stevia, and liqud. Set aside.
Thaw the rhubarb completely (using microwave is fine.) Reserve all juice that comes off. Heat a batch at a time (3 or 4 good heaping cups / handfuls) in microwave to piping hot. Again reserve all juice that comes off. Use this juice as part of the water / juice liquid requirement. Top up if needed with water or juice. Keep rhubarb covered to keep it hot.
Put the Clearjel mixture pot on to cook over medium high-heat.
When it starts to thicken, which will be very soon, add the lemon juice.
Cook for 1 minute.
Add rhubarb, then cook for 3 more minutes to heat through, then remove from heat. Stir carefully to break down the rhubarb as little as possible.
Ladle pie filling into ½ litre (1 US pint) or 1 litre (1 US quart) jars.
Leave 3 cm (1 1/4 inch) headspace.
Debubble, adjust headspace.
Wipe jar rims.
Put lids on.
Process in a water bath or steam canner.
Process either size jar for 30 minutes; increase time as needed for your altitude. See chart below.
Rhubarb Pie Filling (Sugar-free). www.healthycanning.com