Method

• 1.
  Combine the vinegar, sugar and 2 cups (500ml) water in a saucepan over low heat. Stir to dissolve sugar, then add the peppercorns and cumin seeds. Increase heat to medium and bring to the boil. Remove from the heat and allow flavours to infuse for 15 minutes. Bring back to a simmer and, working in batches, slip cumquats into the brine for a 1-2 minutes until glossy and softened slightly. Remove with a slotted spoon, then set aside in a bowl. Repeat with remaining cumquats.
• 2.
  Carefully divide cumquats among five 2 cup (500ml) sterilised jars, adding a cinnamon quill and a clove to each. Pack as many cumquats into each jar as possible without bursting the skins. Carefully fill jars with brine until cumquats are completely covered. Remove any air bubbles by gently tapping each jar on the work surface and sliding a butter knife around the inside. You may need to add more brine or cumquats after doing this (the liquid should reach 1cm from the top). Wipe the rims of the jars and seal.
• 3.
  Lay a folded tea towel in the bottom of a large deep saucepan, then sit jars on the tea towel, keeping them clear of each other and the sides. Roughly matching the water temperature to the temperature of the jars, pour in enough water until jars are at least three-quarters submerged. Bring to the boil over medium heat and boil for 10-15 minutes until lids are puffed up and convex. Carefully remove the hot jars from the water and set aside overnight at room temperature. In the morning, the lids should be concave. Store any jars that failed to seal correctly in the fridge and use their contents within a few weeks.
• 4.
  Let cumquats sit for at least 1 month before using. Once a jar is opened, store in the fridge and use within 6 months.