Turn off the heat and work quickly. Skim any foam into a bowl using a ladle. Remove the jars from the oven, one tray at a time. Using a canning funnel and a 4 oz ladle, fill the jars almost to the top, leaving about 1/4 of an inch of head space. Have someone follow with a rag to whip any jam from the rim. Next quickly boiled the lids (use a strainer basket, filling some of the lids and shaking in the boiling water for 30 seconds. Then place sterilized lid on each filled jar and seal with a ring. Repeat with remaining sheet trays of jars, one at a time till finished. Let sit to cool. Test the jars after 2 hours, a seal should have formed, shown by an indent in the lid.