1. Empty maple syrup into a medium pot. Boil syrup over high heat until it begins to foam. To prevent syrup from boiling over, stay close so you can take the pot off the burner to bring down the foam. Reduce heat to medium-low.
2. Using a candy thermometer, bring syrup to 115°C (240°F) or leave it to boil until it thickens to a syrupy texture. The syrup should reduce by half. Test the syrup: if it is too runny, return the pot to the burner and continue to boil a few minutes longer. If it is too thick, return to heat, adding a bit of water.
3. Cool before serving.
4. In a large serving dish, place clean snow or crushed ice, pressing it into the dish. Pour syrup over top using a ladle.

Chef’s tip: Never stir boiling syrup, as it will crystallize.