Blood Orange Sorbet

December heralds the start of the season for citrus fruits, which are harvested in southern Europe during the winter months. Satsumas, clementines and Sicilian lemons all appear on the greengrocers' shelves. The citrus flavours and bright colours make a great contrast to the brassicas and root vegetables which are also in season at this time of year. One of my favourite citrus fruits is the blood orange, which usually appears in late December. My greengrocers got a single box shortly before Christmas, and I am such a sucker for a blood orange that I bought about half of them. Blood oranges have a particularly fresh flavour, and a great balance of sweet and sour, which epitomise the tangy quality that makes citrus such a great flavour. The flesh of blood oranges is flecked with red, which gives them their name. This strong colour also makes a great visual impact. (Some blood oranges are bloodier than others - the batch I used in this recipe were fairly bloodless.)

Blood oranges and Sicilian lemons

Blood orange sorbet makes a great light dessert or palate cleanser. I made some this weekend, being full up to my eyeballs with Christmas pudding and chocolates and in need of something different. Ice creams and sorbets are pretty easy to make at home with an ice cream maker, which will churn and freeze the ice cream or sorbet. The important thing with sorbets (which have a lower fat content than ice cream) is to use enough sugar so that they freeze without forming large ice crystals, but not so much sugar as to overpower the underlying flavours. Lots of professional kitchens use dextrose and fructose along with caster sugar to achieve the right balance. This isn't so easy in a domestic setting - as specialist sugars can be difficult to source. In a vague and unscientific attempt to replicate this, I often use a mixture of caster sugar and icing sugar.

Ingredients

750ml blood orange juice (approx 10 oranges)
zest from 2 blood oranges
100g caster sugar
50g icing sugar 

Method

Start by zesting two blood oranges. Put the zest in a small saucepan.

Juice the oranges. Pour about 250ml of the juice into the saucepan containing the zest. There is no need to separate out any flesh, but make sure that there are no seeds in the juice - this should not be too difficult as blood oranges tend to be fairly seedless.

Weigh out the sugar and add to the saucepan.

Place the saucepan on a medium heat. Heat to 85C, stirring with a balloon whisk until the sugar has dissolved and you have a blood orange sugar syrup. Use either a sugar thermometer or probe thermometer to measure the temperature. (If you have neither, heat until you begin to see steam come off the sugar syrup).

Chill the blood orange sugar syrup rapidly. The best way to do this at home is to pour the sugar syrup into a cold metal jug and place the jug in a large bowl filled with ice and water. Stir with a balloon whisk.

Cooling the blood orange syrup

Once the sugar syrup has cooled, add the rest of the blood orange juice and stir to combine. Place in the fridge for at least 12 hours or overnight to chill and to allow the flavours to infuse.

The following day, sieve the syrup to remove any flesh or large pieces of pith. Use a wooden spoon to push all the juice out of the flesh.

Pour the liquid into an ice cream maker and churn until the sorbet starts to turn solid. Transfer to containers and put in the freezer. Although the sorbet will keep in the freezer for months, it is best eaten within a week or so, after which ice crystals will start to develop.