Citrus Cordial

6 juicy lemons
2 large oranges
1.5kg sugar
2.5 litres boiling water
30g citric acid
30g tartaric acid

Scrub the fruit with hot water to remove any wax. Thinly pare the zest off the oranges and four of the lemons. Avoid the pith.

Place the sugar in a large stainless steel pot (I use my pasta pot) and pour over the boiling water. Add the citrus peel and simmer for 10 minutes. Remove from the heat and stir in the citric acid and tartaric acid. Set aside to cool down a little.

Meanwhile halve and squeeze the oranges and lemons. Add to the syrup mix and stir well. Allow to sit, covered, for about four hours. Strain through a sieve to remove the peel and any citrus pulp. Pour into clean, dry bottles and refrigerate.