Steps

1. Place raspberries in a large pot with lemon juice, ¼ cup water, and sugar (or sugar and stevia). Simmer over medium-low heat, stirring occasionally. You may want to reduce the amount of seeds in your jam by straining some of the seeds off and discarding them.
2. After the berries have simmered for an hour, hold a fine metal strainer over your pot. Using a ladle or spoon, carefully scoop some of the hot berry juice into the strainer. Use a spatula to press the seeds against your strainer and push the pulp back into the pot. Scrape the bottom of the strainer to get every last bit of pulp. Discard the seeds. Repeat this process a few times, and your jam will have a smattering of seeds, but not too many.
3. When the jam has simmered for 90 minutes, test it by placing a small spoonful of hot jam on a plate and placing it in the refrigerator for 3 minutes. The consistency should be similar to ketchup — soft, but not liquid. If the consistency is not right, simmer for another 30 minutes and retest.
4. Place the jam in sterilized jars. You can refrigerate the unopened jars indefinitely. I often can the jams using a water-bath method. When canned properly, jam can be stored in a cool place for a year or more.