- 1). Chop the rhubarb and put it in the pot with the milk, grape jelly and ascorbic acid.
- 2). Heat the mixture over a medium heat until it boils, then turn down the heat and simmer until the rhubarb is completely soft.
- 3). Remove the pot from the heat and mash the rhubarb mixture with a potato masher.
- 4). Pour the hot rhubarb mixture into a glass canning jar and screw the lid on tightly.
- 5). Place the jar in a canner. Make sure it contains enough water to cover the jar completely.
- 6). Boil for 90 minutes. When the time's up, the top of the canning jar should have sunken in, meaning that the lid is now tightly sealed on the jar.
- 7). Remove the jar from the canner, let it cool and store it in your pantry.