To get the raspberry juice, you will need to either use a juice steamer or a jelly bag. To use a juice steamer, follow the operating instructions. To use a jelly bag, begin by adding the raspberries to a large pot. Add a couple tablespoons of water and place over medium heat. Heat the raspberries just until the begin to break down. Remove from the heat and then mash the berries.
Transfer the berries to a jelly bag and hang above a large mixing bowl. I like to tie the bag to a cupboard knob over a mixing bowl on the counter. Allow the berries to drain up to overnight until all of the juice is drained. Discard the pulp.
Preheat the oven to 250°F. Make sure the jars are clean and then place on a baking sheet in the oven for at least 15 minutes before canning. Add the canning lids to a small saucepan with water and place over low heat in barely simmering water. Keep clean tongs and a towel nearby. Gather together a clean ladle, funnel, and damp cloth and have ready to go. Have a potholder ready for the hot pot.
When the canning equipment is all sterilized and ready to go, begin to cook the jelly. Add the lavender to a tea bag or cheesecloth sachet.
Add the raspberry juice to a large pot along with the lavender tea bag. Stir in the pectin and then bring to a boil over medium high heat, stirring constantly. When the juice comes to a full, rolling boil, add the sugar all at once. Stir until the sugar is dissolved, skimming occasionally as needed.
Bring the jelly mixture back up to a boil and cook for 1 minute. Remove from the heat and then remove the lavender tea bag. Quickly skim the jelly one last time.
Immediately transfer the pot to the potholder. Use tongs to remove a jar from the oven. Use the funnel and ladle to fill the jar with the hot jelly, leaving a half inch space from the top.
Use the damp cloth to wipe the rim of the jar to clean any spills. Use the tongs to remove one of the canning lids from the hot water and wipe dry with the clean towel. Place the lid on the jar and then add the screw top. Hold the jar with a towel and screw the lid on as tightly as possible. Set the jar aside being sure not to press down on the top of the lid – this could give the false impression that the jar has sealed when it hasn’t. Repeat with the remaining jelly.
Check the jelly jars after an hour or two to see if they have sealed. A properly sealed jelly jar will make a small popping sound as the lid seals and the top will go from looking rounded to indented. Any jelly that hasn’t sealed can be stored in the fridge and used within a few weeks. Sealed jelly can be labelled and stored in the pantry for at least a year. When opening the jelly, check that it is still sealed and for any signs of mold or spoiling. Discard if you notice any spoilage. Enjoy!