Strawberry Rhubarb Spread

Combine rhubarb, strawberries, lemon juice, and pectin in a large cooking vessel over medium heat. Stir constantly until the mixture reaches boiling point. Introduce sugar gradually, stirring continuously until it's fully incorporated and a syrupy consistency is achieved.

Increase the heat to high, maintain a rolling boil, and cook for 1 minute. Discard any foam that forms on the surface.

Sterilize jars and lids by submerging them in boiling water for at least 5 minutes. Utilize a jelly spoon and ladle to fill hot, sterilized jars with jam, leaving approximately 1/4 inch of space at the top. Utilize a knife or thin scraper to remove any air pockets that may have formed.

Clean the jar rims with a damp cloth, eradicating any residual food particles. Secure the lids tightly onto the jars.

Position a rack at the bottom of a large container and fill it halfway with water. Bring the mixture to boiling point over high heat, then carefully place the jars into the pot using a holder. Maintain a 2-inch gap between the jars and pour in additional boiling water to cover them by at least 1 inch. Boil for 5 minutes, then cover the container.

Remove the jars from the pot and allow them to rest, spaced apart by several inches, for 12-24 hours. Press the center of each lid gently with your finger to verify that it doesn't move up or down. Remove the rings for storage and store the jars in a cool, dark location.