Wash the cucumbers and put them in a bowl. Cover with salt water. Take 75 g salt for 1 litre of water. Cover and leave to stand in a cool place for 12-24 hours. Wash the cucumbers thoroughly afterwards.
Peel the shallots. Peel horseradish and cut into thin slices. Wash the dill and pluck off the tips. Layer cucumbers, shallots, horseradish and dill alternately in a stone pot. Boil up vinegar, 1 1/2 litre water, sugar, mustard seeds, allspice and bay leaves while stirring.
Remove from the heat. Stir in the preserving aid. Pour the liquid over the cucumbers so that they are well covered. Let them cool down. Then close the pot with preserving cellophane, parchment paper and lid.