Mix the berries with the sugar, lemon juice, and the vanilla bean (the split pod and the seeds) in a big pot.
Cover the mixture and let the berries macerate in the fridge overnight.
Place the pot on the stove, uncovered and bring the mixture to a boil, stirring occasionally.
When the jam comes to a boil, continue cooking it until it hits the jam setting point, around 102 ºC (215 ºF).
Remove from the heat. Fish out the used vanilla bean pod and discard it.
Divide the jam among the jars, leaving a ¼ inch headspace. Remove air bubbles, wipe the rims clean, then cover with the lids, fingertight. If any of the jars aren't filled full, don't seal them. Instead you can cover them and enjoy them right away, storing in the fridge.
Seal the closed jars according to the manufacturers recommendations using a water bath canning kit. I used Bernardin jars and I boiled my jam jars for 10 minutes to seal them.
Remove from the canner. Let sit 24 hours undisturbed before storing them in the pantry.
Notes
This recipe makes 6 small jars (of 125 mL (½ cup) each) or 3 large jars (of 250 mL (1 cup) each)Make sure to sterilize your jars