To begin, wash and prep all of your canning supplies. Jars should be washed and inspected for flaws and warmed. To warm the jars, place them on a baking sheet in the oven, with the temperature set to warm. If you warm the jars in your canner, there will be moisture in the jars, and this can effect your syrup.
Begin preheating your hot water bath or steam canner.
Pour the maple syrup into a large, non-reactive pot, and bring it up to a boil. Reduce the heat to a simmer, and begin ladling the hot syrup into hot jars.
The headspace for your jars is 1/2 inch - the distance from the top of the jar to the top of the syrup.
Wipe the rims of the jars with a damp cloth dipped in white vinegar.
Place a lid and ring on the jar (finger tight) and place the jar in the hot water bath or steam canner. Do this with all of the maple syrup jars.
Process your jars for 15 minutes. The time is the same for both pints and quarts. (See the note about adjusting time for elevation in the article above. Processing times for canning recipes are always give for under 1000 ft elevation. You must make adjustments if you live at a higher environment.)
After the jars have processed, turn off the heat, remove the lid of the hot water bath canner, and let the jars rest for 5 minutes. If using a steam canner, turn off the heat, but leave the dome lid on, and wait for 5 minutes.
Transfer the jars to a lined surface in a draft-free location and let them sit for 12-24 hours. You can cover your counter with folded kitchen towels, or use a cooling rack.
Remove the rings, test the seals, wash and label the jars. Store them away in the pantry.
Now you have maple syrup that will remain shelf stable for much longer.
Use as needed.
Notes
These instructions are flexible with the quantity. A gallon jug of maple syrup will give you 4 quarts or 8 pints.