Heat the vinegar and water with the cloves and allspice in a pan until close to boiling. Remove from the heat and leave to cool. Thoroughly wash two large glass jars with secure lids. To dry and sterilise the jars, place them on a baking tray in the oven on a very low heat (120ºC, 250ºF, Gas Mark 1) for 5-7 minutes.
Cut each beetroot into eight even-sized pieces and place in the jars. Fill the jars with the cooled vinegar mix and leave for at least a week before eating. Store in the refrigerator.
Makes 2 x 500 ml (16 fl oz) jars.