How to sterilise glass jars and bottles

How to sterilise glass jars and bottles:  a step-by-step process.

  1. Make sure you have bottles and jars with clean, well-fitting lids that will be airtight and leak-proof.  Check that there are no plastic parts (especially on swing-top bottles) that will be damaged in the oven*.
  2. Preheat oven to 120 °C.
  3. Remove lids from jars, wash jars and lids in hot sudsy water, rinse well and allow them to drain for a few minutes to remove excess water.
  4. Place lids, tops up, in a heatproof bowl and keep aside.
  5. Place jars, neck up, on an oven tray and place tray in oven for minimum 20 minutes. This will sterilise the jars for immediate use. Remove from oven with care – they are very hot and may slip on the tray. Allow to cool slightly on the tray, but it’s best to fill the jars while they are still warm. For bottles, fill using a clean funnel that has been scalded with boiling water.
  6. When jars have been filled, pour boiling water over lids and allow to steep for five minutes. Drain through a clean sieve or colander and shake to remove excess water. Seal jars while still warm and screw to seal securely.
  7. Using oven gloves, invert the jars and allow to stand upside down for five minutes so that the hot contents incorporates any excess moisture from the lid.

* Note: For bottles with plastic swing-tops or Stelvin (wine bottle) screw-caps, it would be better to steam sterilise in a deep stockpot. Place a clean metal steamer or cake-rack on an inverted heatproof bowl  in the bottom of the stockpot or, alternatively, use a spaghetti cooker which has a deep perforated insert. Stand the bottles, unsealed, upside down on the steaming rack. Pour water into the pot to just reach the rack, and bring to a good boil. Allow the bottles to steam over the boiling water for half an hour, taking care to add more boiling water to the pot so it doesn’t boil dry. Stelvin caps can be steamed at the same time. Leave in pot to drain out excess water.