Wash your gherkins, sprinkle them with salt, and leave to stand for 2–3 hours, occasionally tossing them gently. Shake off the salt and place the gherkins in a bowl, cover with clean boiling water, and leave them to stand for 5 minutes. Drain.
Place the gherkins in clean, sterilized sealable jars, adding a healthy, many-fingered pinch of pickling spice to each jar. Meanwhile place the sugar, acid and water into a stainless-steel pan and boil until the sugar and acid have dissolved. Pour hot over the gherkins.
Seal the jars while the liquor is still hot. Keep in your cupboard for at least a month before eating.