500 gmblood plums, stones removed, coarsely choppedAbout 275 gm (1¼ cups) white sugar1vanilla bean, scraped seeds only25 ml eachlemon juice and orange juice1 tbspwhite vinegarTo serve:soda water or good-quality lemonadeTo serve:lime wedges and ice cubes
Combine plums and 2 cups water in a saucepan, bring to a simmer over medium-high heat and simmer for 15 minutes. Strain through a fine sieve, pressing to extract juice, discard solids, then strain liquid through muslin and measure liquid.
In a clean pan, combine plum liquid and an equal quantity of sugar and stir over medium heat until sugar dissolves. Add vanilla seeds and juices, bring to the boil, reduce heat to low-medium and simmer for 5 minutes. Remove from heat, add vinegar and stir to combine, then transfer to a sterile glass bottle, seal and refrigerate until required.
To serve, pour cordial into glasses, top up with soda water or lemonade to taste, add ice and a squeeze of lime.