Place 6 clean 250 ml mason jars on a rack in a boiling water canner; cover jars with water and heat to a simmer (180°F/82°C). Set screw bands aside; heat SNAP LID® sealing discs in hot water, not boiling (180°F/82°C). Keep jars and sealing discs hot until ready to use. Wash and hull strawberries. Working in small batches, purée berries in a food processor fitted with a metal blade just until smooth. Measure 4 3/4 cups (1175 ml) into a large, deep stainless steel saucepan. Add maple syrup, apple juice and lemon juice. Stirring frequently, bring mixture to a boil. Slowly whisk in Fruit Pectin, stirring until dissolved. Return mixture to a full boil and boil hard 1 minute. Remove from heat.
Ladle hot smooth into a hot jar to within 1/4 inch (0.5 cm) of top of jar (headspace). Using nonmetallic utensil, remove air bubbles and adjust headspace, if required, by adding more smooch. Wipe jar rim removing any food residue. Centre hot sealing disc on clean jar rim. Screw band down until resistance is met, then increase to fingertip tight. Return filled jar to rack in canner. Repeat for remaining marmalade.
When canner is filled, ensure that all jars are covered by at least one inch (2.5 cm) of water. Cover canner and bring water to full rolling boil before starting to count processing time. At altitudes up to 1000 ft (305 m), process –boil filled jars – 10 minutes.*
When processing time is complete, remove canner sealing disc, wait 5 minutes, then remove jars without tilting and place them upright on a protected work surface. Cool upright, undisturbed 24 hours; DO NOT RETIGHTEN screw bands.