Heat it up, stirring occasionally, until it starts to boil.
Turn down the heat and let it simmer for 3 minutes.
Remove the syrup from the heat and pour it into a large flat baking pan to cool. This will help it cool faster and also provide a larger surface area for the smoke to contact the syrup.
After the syrup is cooled to room temperature, place the pan into the fridge for at least a half hour. Chilling the syrup will help the smoke infuse faster.
Smoke the Syrup (Handheld smoker)
If you are using a handheld smoker, seal the top of the baking pan with cling film. Then, lift up one little part of the film and insert the tube from the smoker. Seal up the cling film around the tube as best as you can.
Add a pinch of the wood chips to the smoker and light them with a kitchen torch or long lighter. Turn the smoker's fan on so the smoke goes through the tube and into your sealed pan setup.
When the pan setup is filled with smoke, take out the tube and quickly reseal the cling film. Let the syrup rest for about 5 minutes in the smoke.
Repeat this smoking process as many times as you'd like to get a stronger flavor. Each time you will also get a slightly deeper color to the syrup.
Smoke the Syrup (Grill or Traeger type smoker)
If you are using a grill or a dedicated smoker, add the pan directly to the grill.
Add in the wood chips and light them up per the grill's instructions. Then, let the pan smoke for one to two hours.
Bottle and Store
Pour the syrup through a funnel and into your resealable storage bottle.
Store the syrup in the refrigerator for up to 2 weeks. Discard at any sign of mold.
Notes
For a longer storage life, add an ounce of vodka. The alcohol will slow the growth of any mold and allow you to keep it in the fridge for an extra week or two.