High acid water bathing is a great method of preservation for bottled fruits, cordials and low sugar jam and preserves. It is a simple method that ensures long and safe storage of your preserves. Traditionally in Australia the Fowlers Vacola jars and preserving units have been used for preserving but the method easily transfers to a stove top method.

Principles of High Acid water bath preserving

Through the heating process, surplus air/oxygen is expelled from the jar and anything remaining in the bottle is sterilised. The sterilisation process eliminates food spoiling agents already present in the fruit and the natural acidity of the fruit prevents any further spoiling. The rubber seal allows air to exit and when the contents of the jar are cool, it creates a vacuum seal. The three main factors for successful preserving are;Most fruits are high in acid although some fleshier and tropical fruits require the addition of citric acid or lemon juice.

  1. Acidity
  2. Correct sterilisation
  3. Vacuum seal.

Low acid foods like most vegetables can be preserved / canned using a pressure cooker. This requires a different set up and specific equipment.

Preserving Liquids

  • Preserving liquids are necessary when preserving whole fruit. When the fruit is stewed or pureed they are not needed.
  • Water – We use filtered water in 99% of our preserves. When the fruit is ripe and the flavour good the water will become syrupy and sweet.
  • Sugar syrup – is good for some fruits as it increases flavour e.g. peaches and mango. 1 cup sugar to 3 cups of water is considered a ‘light’ syrup but is quite sweet.
  • Fruit Juice – this is a great option if you have loads of fruit. Puree or juice the fruit and add to whole fruits in the jar.
  • Honey & golden syrup – can be used but adds its own flavour to more delicate fruits. Make it into syrup first with water (warm it in a saucepan till it’s dissolved) but halve the quantity you would use for sugar.
  • Brown &, raw sugar tends to overpower the flavour of the fruit and can make the contents appear cloudy. If using these sugars, make a syrup before adding to the jar.
  • Fruit concentrates – We use these more than any other sweetener because they are easy to add and are fruit based. We often put a couple of teaspoons on the top of the packed jar of apples and pears.

Preparation of fruit


Use firm ripe fruit with no blemishes or spots. Softer and riper fruit can be stewed or pureed prior to processing.


Get rid of dirt, orchard spray and if collecting from urban areas, diesel and airborne pollutants.


Removes the skins but is also used to soften and moisten fruit. Fruits that absorb water in preserving process e.g. apples will absorb all the preserving liquid and leave you with dry looking and tasting preserves.

Preventing discolouration

Add ascorbic acid or work fast and not worry too much about colour unless you are exhibiting at the Royal Melbourne Show!

Processing step by step with a Fowlers Vacola unit or a stove top set up

  1. If using Fowlers Vacola (FV) bottles, soak the rubber rings in warm water for approximately 15 minutes, this softens them and makes it easier to get onto the jars
  2. Stretch the softened ring around the neck of the clean jar and run your finger around the ring to make sure that it has settled evenly into the groove of the jar and is not twisted.
  3. Pack the jar with fruit placing the cut surface of the fruit close to the centre.
  4. Add water or syrup to a layer of fruit as you proceed, alternate packing a layer of fruit and then covering with water/syrup. This is the key to preventing any air pockets from being trapped. A packing stick is a useful tool that helps to hold the fruit in place, as you are packing.
  5. Leave about 1 cm at the top of the bottle before placing the lid on top,
  6. If using FV jars, make sure that the rubber ring isn’t visible to ensure that it is positioned correctly. Then place the clip across the centre of the lid and snap into place. For all other jars screw new lids on firmly. New lids ensure a good seal. (New lids are available from a variety of kitchen supply outlets and online from 30c up to a couple of dollars depending on the size)
  7. If you are using the stove top method place a round cake rack or a couple tea towels on the bottom of the pot so that the jars are not sitting directly on the bottom.
  8. Fill the FV unit or large stock pot with water so that the bottles are completely covered. Preferably by 2cm of water.
  9. To process the jars, raise the temperature of the water very slowly to 92 °C, taking about 45 – 60 minutes. Maintain the temperature at 92°C for 10 – 20 minutes or up to a total of 70 minutes for larger jars
  10. The water should not be allowed to boil, so set the timer and make sure the heat is turned off at the required time. If it starts to boil before then don’t let it boil longer than two minutes.
  11. Remove the jars using oven mitts or special tongs and leave the jars to cool for 12 to 18 hours on a wooden surface or newspaper before removing the clips and / or checking the seals. You can also leave the jars to cool in the water.

Keep the unit on a wooden board whilst processing to ensure heat does not dissipate and under process your preserves. When you have finished and the water has cooled you can fill the watering can and water the garden. The bottles of fruit should be stored in a cool dark place. Preserved fruit can keep for many years, but are at their best for about a year.