You want sugar content, by weight, to eventually equal 65% of the mixture. I’d start with 50%-55% sugar by weight, so you don’t get too sugary a result. Going lower than this could cause you to cook the jam too long to remove water, and the long cook will make it less fresh tasting (and remove the natural pectin). You could adjust with added pectin and/or acid too, if you drop the sugar.
Mixed Berry Jam
Servings: 0
Ingredients
- 500 g strawberries
- 550 g other berries e.g., ½ raspberries, ¼ blackberries, ¼ loganberries
- 550 g sugar
- ¼ cup lime juice ~3 limes
- 1 tbsp pectin
Instructions
- Put spoons in the freezer. First, clean and crush the berries. Start by washing them and picking through for any obvious issues. Remote the tops from the strawberries. Roughly chop the strawberries. Add everything to a very large pan – preferably one that is both wide and quite deep. Weigh out the sugar in a bowl. Sprinkle just a small amount of the sugar onto the berries and toss. Let sit for a few minutes while you prep jars and clean up a little, to get ready for the next steps. (Clean the jars, lids and bands, prepare the water bath canner for sterilizing jars, etc.)
- Once you have everything else ready, more or less, crush the fruit some (it should have sweat some, from the sugar). Put the berries over a medium heat, add about half of the lime juice, and stir until everything is liquid. Now, add the rest of the sugar and the pectin and cook over medium-low, stirring frequently. Watch for foam and stir it down when needed.
- Sterilize the jars, since you’ll be processing them for less than 10 minutes. Do this by filling the canner you’ll be using with the empty jars and boiling for 10 minutes. Preheat the oven to 180ºF, so you can keep them warm. Remove each and drain the water back into the canner, for use during processing. Place sterilized jars in a large Pyrex baking dish and place in the oven while you finish the jam. Leave the water and canning setup.
- At this point, the jam will hopefully be reaching temperature. You need it to get to 217ºF to 226ºF, which demonstrates enough water has evaporated that the mixture is now 65% sugar. If you haven’t quite reached this temperature, turn up the heat some and stir until water evaporates away.
- Once it reaches the correct temperature, test the consistency with the spoon test. (Take a frozen spoon, dip it in carefully and put in the fridge for a minute or so. Test consistency once it’s cooled.)
- When it’s done, remove the jars from the oven and turn off the oven. Turn the heat back on for the water bath canner. Fill each of your jars with jam, leaving just ¼” headroom. Place lid on top and screw the lid on finger-tight. Place in the water bath canner, careful not to tip them over.
- Bring the canner to boiling for 5 minutes. Then turn off the heat for about 10 minutes and then remove the jars. Do not disturb for 12-24 hours. Then you can remove the lids and check seals.