Watermelon and rosewater jam
The delicious summery taste of this watermelon jam is thinner than a standard one. It is extraordinary served with a sharp-tasting cheese.
- Cut the rind off the watermelon, remove as many seeds as possible, then cut the flesh into chunks. Place the pieces in a bowl, then sprinkle the sugar and juice of a lemon over the top. Refrigerate overnight.
- The next day, place the mixture in a deep saucepan with the rosewater and pectin, then bring to a gentle simmer.
- Cook the jam for an hour - skimming off any froth as it cooks - until it thickens enough to drop slowly from a spoon.
- Pour into sterilised jars, then seal carefully.
When preserving any food, it is crucial to get the basics right. First, prepare your jars by immersing them in boiling water for 10 minutes, or place dry, scrupulously washed jars in a 120C oven for 30 minutes. The jars must still be warm when you pour in the hot jam. Seal immediately with a suitable lid. Never place hot jars on a cold surface, as they may shatter; instead, always stand them on a tea-towel-lined tray.
There is much debate about how much sugar to add to the fruit when preserving, with many recipes suggesting an equal weight of sugar to fruit. I work on a rough ratio of half the fruit weight in sugar, as I prefer my jams soft and gently set. The actual setting point temperature is 104C, but the firmness of the set is really determined by the pectin content.
Some fruits, such as strawberries and cherries, are low in pectin, so you will need to add it in the form of apple juice or another fruit, such as plums, that has a naturally high pectin level. Alternatively, use a commercial pectin powder.
To test the pectin level of your cooked jam, place a spoonful in three tablespoons of methylated spirits. If a single, transparent ball forms, there is enough pectin present to set the jam; a few smaller lumps indicate a medium level of pectin; many small lumps indicate a low level. The jam can be eaten as soon as it cools, but I always put some aside to brighten the shivery days of winter.