Until the nineteenth century human beings were dependent on the natural processes of drying, fermenting, salting, pickling, and in northern climates freezing for food preservation.
In 1800, Napoleon Bonaparte offered a 12,000 franc reward to anyone who could devise a method for the food preservation in order to provide his troops with daily rations in order to keep his armies adequately supplied while on the march. After years of experimentation, Nicolas Appert submitted his invention of bottling and won the prize in 1809.
A year later an Englishman, Peter Durand, adapted the process. He placed wholesome food in clean metal containers, which were then sealed and boiled long enough to kill the spoilage-causing micro organisms. These were similar in shape to tea canisters and the name can came into common parlance.
After 1900, home canning of all types of food, mainly in glass jars, became popular as a means of utilizing home garden products, providing better diets, and reducing the cost of living
In the UK and Australia this process of preserving food is known as bottling but in the USA it is usually known as canning. For domestic food preservation the terms are effectively interchangeable.
Usually used for fruit domestically but it can be used for vegetables, bottling or canning is a relatively simple method of preserving, providing it is carried out correctly and efficiently. Heating to the appropriate temperature, using the right container, keeping at temperature for the right amount of time and secure sealing of the bottles is essential.
Equipment Required for Bottling or Canning
- Sterilizing Pan - If the bottling is to be done on the hob this is essential. This can be a purpose-built sterilizer complete with false bottom and thermometer, a large preserving pan or the base of a pressure cooker. What is essential is that it needs to be deep enough to contain a false bottom, a wooden or wire rack is ideal, and still hold enough water to completely cover the bottles. The bottles must not come into direct contact with the pan or they will crack.
- Bottles - There are two types of bottles available from numerous manufacturers, one with a spring-clip top and the other with a screw band, available in several sizes. The most useful sizes are 500ml or 1lt.
o Spring-Clip Top Bottles – Normally have a glass top and a rubber ring between the lid and the rim of the bottle. This helps to form a complete seal when the bottle has been processed.
o Screw Band Bottles – Usually have a glass or metal lid fitted with a rubber ring kept in place by a band which screws on. During processing (except be the oven method) this band should be loosely screwed on and then tightened while the bottle is cooling.
- Rubber Bottle Rings – If you use separate rubber rings make sure they are the correct size. Always use new rings, once they have been used they stretch and may not form a satisfactory seal.
- Thermometer – Special thermometers registering up to 110°C are available for bottling and jam making and, although, not essential make life a lot easier. You can find a jam making thermometer at very low cost on this site that reads up to 200°C.
- Long handled wooden spoon – For packing fruit into larger bottles.
- Bottling tongs – Not essential but helps when handling hot bottles
- Large baking tray – For the oven method of bottling to stand the bottles on.
- Pressure Cooker – For processing fruits using this method.
Preparation of Fruit for Bottling
Fruit used for bottling must be fresh, firm, and free from discoloration and disease. Wash hard fruits in cold water and leave to drain in a colander. Soft fruits can be soaked for a few minutes in salted water to remove any grubs or insects, rinsed in fresh cold water and left to drain.
- Apples and Pears – Peel, core and cut into quarters or slices and place into lightly salted water to prevent discoloration. Rinse quickly in cold water before packing in jars. For a solid pack, prepare as above and blanch in boiling water for 2 or 3 minutes or steam over boiling water until just tender. Pack warm.
- Apricots, Peaches, Plums and Damsons - Remove stalks and rinse. May be bottled whole or halved with the stones removed. If halved, pack quickly cut side down in jars before they discolour.
- Strawberries - Hull and rinse the berries carefully.
- Blackcurrants, Redcurrants and Gooseberries - Top and tail. Wash and drain well before packing into jars.
- Cherries – Remove stalks and rinse.
- Blackberries, Raspberries and Loganberries – Remove stalks and rinse. These fruit attracts maggots so pick over carefully.
- Rhubarb – Remove leaves and base, wipe sticks and cut into even lengths suitable for the size of the bottle.
- Tomatoes - Remove stems, wash in cold water and drain. Pack with or without the skins. The skins can easily be peeled of if the tomatoes are put into boiling water for 5 to 15 seconds and then dipped in cold water. For a solid pack, cut in halves or quarters. Pack tightly in the jars, sprinkling salt on each layer. Press the tomatoes well down in the jars but do not add any liquid.
Bottling (Canning) Syrup
Fruit may be bottled in syrup, water or a brine solution. Syrup is preferable as it helps to preserve the colour and flavour. The strength of the syrup depends on the sweetness of the fruit and how it is packed. For syrups the proportions are generally 250g to 600ml and water.
The sugar for use in syrups may be granulated or loaf or, for a different flavour, honey or golden syrup. Dissolve the sugar in half of the water over a moderate heat and, when the sugar is dissolved, boil for one minute. Then add the remainder of the water. Doing it this way saves time in waiting for the syrup to cool sufficiently for use. If the syrup is cloudy, strain it through muslin as clear syrup gives a better finish to the fruit.
Bottling (Canning) Brine for Tomatoes etc.
A brine solution is best for tomatoes. Make it with 1 tablespoon of salt to 1 litre of water. If they are to be packed solidly no water is necessary but 1 teaspoon of salt should be added to each 450g of tomatoes.
Packing the Bottles
- Rinse the clean bottles in cold water, drain them but do not dry them – it is much simpler to pack the fruit into wet bottles as it slips down better.
- Soft fruits should be packed as tightly as possible in layers without squashing and adding syrup or water every 4 or 5 layers.
- Hard fruits may be pressed down with the handle of a wooden spoon and the syrup or water poured down the sides of the bottle gradually until it covers the fruit.
- Twist the bottle from side to side as you add the syrup or water to remove any air bubbles.
Methods of Bottling
Processing the bottles may be done on the hob or in the oven. The hob method is known as the water-bath method of which there are three variations, the slow water-bath, the quick water-bath and Pressure Cooker. The oven method has two variations; slow oven - dry pack and moderate oven - wet pack
- Pack the bottles with fruit and pour in enough cold syrup (or brine) so that it comes to the top of the bottle.
- This is best done slowly to allow the syrup to penetrate to the bottom of the bottle. Place the lid on top of the bottle and secure it with a spring clip or screw-band. If using a screw band, loosely screw on.
- Place the bottles in a deep container with a false bottom, making sure they do not touch each other or the sides of the container. Completely cover them with cold water, cover the container with a lid.
- Bring the water slowly to the boil. The temperature of the water should be raised gradually from cold to 55 °C in about an hour and then up to the required temperature for the contents for another 30 to 35 minutes. (See Bottling and Canning Processing Chart).
- Do not try to rush this process, if the water is heated too quickly the fruit may rise in the bottles and more time may be needed at the maximum temperature to enable heat to penetrate the fruit in the centre of the bottle.
- When the processing is finished, switch off the heat and remove the bottles one at a time with a pair of tongs or thick cloth and put them onto a wooden surface and immediately tighten the bands on the screw-topped bottles. Leave for 24 hours before testing that the seal is complete.
- Similar to the slow water-bath method and recommended when no thermometer is available. For best results though temperatures are given for those with a thermometer.
- The main difference between the two methods is that hot syrup at 60°C is poured into the packed bottles and these are then placed in the container and covered with warm water at 38°C.
- Heat slowly so that the water reaches simmering point, 88°C in 25 to 30 minutes.
- Continue simmering for the recommended time. (See Bottling and Canning Processing Chart). If the bottles are over 1kg) extra capacity will be required. Remove and finish the jars as in the first method.
A quick method of bottling fruit as the temperature of boiling point is raised when under pressure, thus reducing the processing time and saving energy. The cooker must have a false bottom and be deep enough to take the bottles. It must also be capable of a maintaining a steady low pressure (L).
Pressure cookers are fitted with a weight gauge that is usually measured by the appropriate letter, L, M, H. (5lbs, 10lbs and 15lbs pressure)
- Pack the fruit in warm bottles and fill with boiling syrup to within 25mm of the rim. Fit rubber rings, lids and clips. Again, if using screw bands, loosely screw on.
- Pour 850 mm of boiling water into the cooker before inserting the bottles.
- Put the lid on the cooker, with the vent open, and heat until steam appears.
- Close the vent and bring the pressure up to Low (L).
- The time taken from that start of heating until pressure is reached should be no less than 5 minutes or more than 10.
- Check the Bottling and Canning Processing Chart for the time necessary to maintain pressure. Remove from the heat, leave the bottles in the cooker and allow 10 minutes before letting the pressure off.
- Remove the bottles and finish as in the previous methods.
Slow Oven – Dry Pack
This method is not suitable for light coloured fruits which discolour in air – apples, pears, peaches, apricots etc – or for solid pack tomatoes.
- Pre-heat the oven to 120°C.
- Pack the bottles with the fruit but do not pour over the syrup or liquid.
- Place the lids on top but without the clips or screw bands.
- Put the bottles onto a baking tray or mat of thick cardboard in the centre of the oven.
- Allow at least 50mm between each bottles and sides of the oven. The success with this method rests in the quick filling and sealing of the bottles as soon as they are removed from the oven.
- After the processing time (See Bottling and Canning Processing Chart) remove the bottles one at a time and fill quickly to the top with boiling syrup or water, securing the lids with clips or screw-bands immediately. If the fruit has shrunk down in the bottles, add fruit from another bottle before pouring over the syrup or water.
- Leave for 24 hours and test for seal.
Moderate Oven – Wet Pack
This method can be used for all types of fruit and also for solid pack tomatoes.
- Pre-heat the oven to 150°C.
- Pack warm bottles with the fruit and poor in boiling syrup, bring or water allowing 25mm head space.
- Place the lids on top but not the clips or screw bands.
- Put the bottles 50mm apart on a baking tray or tin lined with newspapers (in case any liquid boils out during processing) on the centre shelf of the oven.
- After the processing time (See Bottling and Canning Processing Chart) remove the bottles one at a time and secure the lids with clips or screw bands.
- Leave for 24 hours and test for seal.
Testing the Seal
After the bottles have been left for 24 hours and are completely cool, it is necessary to ensure that a complete vacuum has been formed during the processing and that no air is in the bottles. Remove the clips or screw-bands, lift the bottles carefully by the lids and, if these are tight and secure, the seal is complete.
If the lids are loose the fruit should be reprocessed although the quality will be affected. Alternatively it may be better to use the fruit within a couple of days.
Storing the Bottles
Wipe the bottles to remove any stickiness and label with the contents, type of liquid used and date. If a lot of bottling is done, use them on a first bottled, first used principle. Store in a cool, dry, dark place.