Choose ripe, sweet, firm grapes without bruises or soft spots. Wash the grape clusters thoroughly under cold running water.

Gently remove individual berries from the stems, discarding any damaged or underripe grapes.

Sort by variety if desired.

Wash glass jars and lids in hot soapy water and rinse well.

Place them in a large pot of boiling water for 10 minutes to sterilize, or run through a dishwasher cycle.

Let them drain on a clean towel.

Fill each clean jar with grapes all the way to the top, packing them snugly but gently to avoid crushing.

You can use one variety per jar or create attractive layers alternating white and dark grapes.

Add 1 tablespoon of sugar to each 500ml (1 pint) jar. For larger 1-liter jars, use 2 tablespoons of sugar.

Pour clean filtered or boiled and cooled water into each jar, covering the grapes completely and filling to within 1cm (½ inch) of the rim.

Wipe the jar rims clean with a damp cloth to ensure a proper seal.

Place the lids on tightly, securing them firmly.

Prepare a large pot of water and ensure jars are submerged.

Bring water to a rolling boil with jars inside.

Once boiling, maintain for 5 minutes.

Turn off heat and leave jars in hot water until completely cooled.

Check that lids have sealed properly by pressing the center of each lid.

Transfer sealed jars to a cool, dark, dry place.

While technically ready to eat after a few days, the grapes are best enjoyed during winter.

Preserved grapes will keep for 6-12 months when stored properly.