Step 1

Add the lemon slices and elderflower blossoms to a large heat-safe pot or large jar with a lid that's at least 2 litres (8 cups) in size.

Step 2

In a separate pot, add the sugar, water and citric acid and let the mixture come just to a boil (make sure all the sugar has dissolved).

Step 3

Pour the sugar syrup slowly over the lemons and elderflower blossoms and stir well to combine.

Step 4

Let the mixture come to room temperature and cover with a lid (make sure the lid is airtight, so use plastic wrap if necessary).

Step 5

Let the mixture sit for 48 hours, stirring a couple of times each day.

Step 6

After 48 hours, strain the mixture through a strainer and cheesecloth to remove any impurities. You'll be left with a clean-looking syrup that's slightly yellow in colour.

Step 7

Add this syrup to a pot and bring it to a boil. Turn the heat down so the mixture sits at a low boil for about 10 minutes.

Step 8

Add the hot syrup to prepared jars or bottles for canning (this syrup is shelf-stable if proper canning procedures are followed), or store in an airtight container in the fridge for up to 2 months.

Step 9

Mix with still or sparkling water at a syrup to water ratio of 1:8 (about 1/2 cup/120 ml of syrup for every 4 cups/1 litre of water)