Peel and pit the apricots, then slice them, place in a medium sized pot and mash with a potato masher.
Then add the sugar and lemon juice. Place the pot on medium low heat, place candy thermometer in the pot and continue to cook until temperature reaches 220 F (104C) (should take about 20-25 minutes).
Remove the jam from the heat and spoon off the foam that appears on the top.
Pour jam** into clean jars, (no need to be sterilized if you are freezing the jam), leaving 1/2" (1 centimeter) of space on the top, then close with a tight fitting lid.
Let the jam sit 12-24 hours before freezing.
Once the jars are open they can be refrigerated 3-4 days.
**The jam is going to be liquidy when you pour it into the jars but it will thicken when it sets.