Puree peppers with some of the apple cider vinegar. I keep the seeds in the peppers. You can seed for less heat. Add to a 4 c. measuring cup with remaining cider vinegar. Crush berries and add to 4 c. measuring cup to equal 4 cups. ** you can tweek this to taste. My children do not like it very warm, so I'll cut back on the peppers, and add more berries. Just have four cups of produce/vinegar to add to pot with sugar.
Add sugar to 8 quart pot. Add jalapenos, berries & vinegar to sugar. Cook to full, hard boil where you can't stir it down. Boil for ten minutes.
Add one packet of fruit pectin to hot jam. Stir and boil for one more minute. Remove from heat. Most jalapeno recipes suggest 2 packets. I have made it both ways, and have no problem making it with one packet. I can make more batches using just one.
Fill clean jars and seal with warm canning lids and rings as you normally would when making jam. I also turn the ring back just a bit and turn jars upside down for 30-40 minutes.