In a medium pot over high heat, bring water and sliced ginger to a boil. Reduce heat to medium and simmer; 10 minutes. Strain the ginger “tea” to get 1 cup (250 ml) of liquid. The liquid will be cloudy. Add the lemon juice.
Line a half sheet baking pan (18 x 13 inches) with parchment paper. Evenly spread the Redpath® Icing Sugar in the prepared pan. Make indents in the icing sugar using your finger or the handle of a wooden spoon to create moulds for the cough drops.
Pour the ginger tea into a deep-sided saucepan and add the Redpath® Organic Granulated Sugar and honey.
Place over medium-high heat. Stir to combine. Bring mixture to a boil; do not stir once the mixture begins to boil.
Cook mixture until a candy or digital thermometer inserted reads 300°F (149°C), also known as the “hard crack stage”; 12 to 15 minutes. Watch the sugar mixture closely throughout this step as the sugar will bubble up while cooking and can spill over the sides. It will turn a dark caramel colour and become foamy as it cooks.
Immediately remove the pan from the heat as soon as the sugar reaches the correct temperature. Quickly and carefully pour the hot sugar mixture into a large (4 cup / 1000 ml) measuring cup or heat-proof container with a spout. The sugar will foam and bubble up in the new container. It will look foamy and be very dark in colour, like molasses. Be careful while handling the hot sugar mixture as it will be very hot and can burn you. Work quickly but carefully to pour about a teaspoon (5 ml) of the hot mixture into each of the icing sugar moulds.
When all the moulds are filled, let the cough drops cool; at least 5 minutes. Once cooled, toss them in the icing sugar to coat them evenly to prevent them from sticking.
Place candies in a sieve and shake to remove any excess icing sugar.
Line an airtight container with parchment or waxed paper and place the lemon-ginger cough drops in a single layer to prevent them from sticking. Store in a cool, dry place. Alternatively, wrap each cough drop individually in pieces of parchment or waxed paper.
Cough drops will keep well for at least one month.