HomeResourcesResourcesFoodThe Art of Preserving

The Art of Preserving

Preserving makes the most of seasonal fresh produce to enjoy later. Even if you don’t grow your own, visiting farmers’ markets and good greengrocers will give you an idea of what is in abundance and that it the best time to actually preserve them too. This way you have complete control of what is going in your preserves – and they will all be whole foods.

© Maria Ciavarella
My Green Garden

Preserving the abundance is an important element of the slow-food movement, and sometimes a necessary skill if you are a keen gardener, or just a keen foodie. You might have time-honoured recipes handed down from generation to generation that you would like to try but if not, don’t fret as there are many books and weblinks available with recipes galore for many ingredients. Many recipes can be completed in an evening after work, or even started on one night and then continued the next, so even the time-poor can enjoy this culinary art. Who knows? You might even be inspired to show your wares at your local shows! This booklet outlines different techniques for preserving, such as bottling, making jams and pickles which is by no means exhaustive.Preserving slows down food spoilants by altering conditions so that they don’t thrive. This can be done by removing moisture, acidifying the solution, excluding oxygen, using temperature and alcohol.

Warning: Please follow preserving recipes carefully as poorly preserved produce may lead to fatal results. What follows are just tips and techniques for many preserving methods and not strict recipes.

Sterilising jars and lids

Re-use jars that have metal lids many times. The jars are infinitely reuseable if they are intact, but the lids will probably need replacing.

This is necessary to avoid bacteria and other food spoilants contaminating your preserves. After all, why take the effort of making great preserves if they only spoil because the containers aren’t sterile? Luckily, it’s not difficult to do. Re-use old glass jars that come with metal lids, but replace the lids if they are showing wear.

First wash jars and metal lids thoroughly in hot soapy water and rinse well.

To Serilise Glass Jars

Several methods can be used for sterilizing glass jars or bottles.

  1. Put the clean jars in a slow oven (from 110oC – 130oC) for at least 10 minutes. If filling with hot preserves, leave the jars in the oven until they are needed.
  2. Put the jars and lids through a hot rinse cycle in the dishwasher and dry hot in the dishwasher.
  3. Place the washed jars and lids in a deep pan and cover with water. You may want to line the base and sides with a tea-towel to stop them rattling. Bring to the boil and boil rapidly for 10 minutes. Lift the jars out and drain upside down on a clean tea towel. Allow to dry.
  4. Microwave sterilising units (as used to sterilise baby bottles) are a fast alternative to sterilising limited numbers of jars at a time.
  5. In the microwave you can also sterilise by half filling the clean jars with water, heating them in the microwave for enough time to see the water boiling for at least 30 seconds, and then tipping the hot water out before filling with the preserves.
  6. Use Milton sterilising tablets in a large plastic tub. These are usually available in the baby aisle of large supermarkets.

To Sterilise Metal Lids

First of all, ensure that the lids are not showing signs of wear if you are re-using lids. If the paint is worn, there is the potential for the lids to corrode when storing preserves, especially pickles. To sterilise, place the lids in a saucepan with cold water and bring them to the boil for about 10 minutes. Remove and drain on a clean teatowel while waiting to use them.

Preserving Techniques

Heat Preserving

Heat preserving or processing is a great way to have in the pantry fruits that you may have grown in abundance. The fruits are packed into clean jars and then filled with water or a sugar syrup solution . It is best to use under-ripe fruit as they will keep their shape during the heat processing time. Heat processing will vacuum-seal the jars which excludes oxygen, which slows down or prevent spoilants from thriving.

This process is also known as bottling or canning.

Bottling can be done using the Fowlers Vacola preserving unit with its equipment. If you don’t have a Fowlers Vacola unit, you can use clean jars and new metal lids in a large deep pot (eg stock pot) on a stove top hot water bath.

To do this:

  1. Prevent the jars coming into direct contact with the bottom and sides of the pot by placing a metal rack or trivet, or a tea towel on the bottom; and wrap each jar in teatowels or put cardboard between the jars so they are packed in firmly against each other.
  2. Pour in enough water to cover the jars by at least 2.5cm. If the preserves were hot in the jars, use warm water to fill the pot. If they were cold, use cold water to fill.
  3. Turn on the heat and slowly bring the water to the boil. This should take about ½ hour and at no time should boil hard. Once at a slow boil, lower the heat so that a gentle simmer is maintained for the required time. Remove from heat.
  4. If the contents were cooked originally before heat preserving, you can allow them to cool in the water as the water cools down. Otherwise, use tongs to carefully remove the jars, place on a rack or towel-covered surface and leave to cool completely before labelling and storing.

Jams, Conserves and Marmalades

When making jams, conserves or marmalades, there is a magic that happens when certain elements come together. This magic is what makes the mix gel or set to become more than fruit syrup.

FRUIT PULP (softened) + ACID + PECTIN + SUGAR + HEAT = JAM (or Conserve or Marmalade)

Most fruits can be made into jams but certain conditions, such as the amount of acid and pectin, must be met in order to get the jam to gel. Pectin is a substance found in most fruits to an extent that, when at the right temperature and in the presence of acid, reacts with sugar to cause the mixture to set. Slightly under-ripe fruit will contain more pectin that over-ripe fruit, so it’s a good idea to start with fruit early in the season rather than at the end.

Some fruits naturally meet the necessary acid and pectin amounts, but otherwise these ingredients can be added by including lemon juice (contains both pectin and acid); reserving the pips or stones and cooking these as well for the pectin; or adding a commercial setting agent, such as Jamsetta. Remove any bruises or damaged parts from the fruit before using. When adding sugar, you may find the amount of sugar required quite confronting! Keep in mind that the sugar is not just there to create the set of the jam, but acts as the preserving agent in the jam. The sugar concentration creates conditions that discourage spoilants to flourish. The general rule is ¾ to 1 cup of sugar to every cup of fruit mix. If you use the lower amount, you will find that the jam will have a less firm consistency, but more easily spreadable. It shouldn’t however, be runny like a syrup.

Acid & Pectin balance Fruits with good balance of acid and pectin: grapes, crab apples, quinces, grapefruit, lemons, limes, sour apples, sour oranges, sour plums.
High in pectin but low in acid: sweet apples, sweet quinces. You will need to add 2 tablespoons of lemon juice to every kilo of fruit to increase the acid content.
Low in pectin but high in acid: apricots, pineapples, rhubarb, sour peaches. Add 2 tablespoons of lemon juice to every kilo of fruit to increase the pectin content and add the lemon pips in a muslin pouch to the cooking of the jam (remove once finished!).

Fruits low in pectin and low in acid: Pears, melons, sweet peaches, some berries and cherries. These will need the addition of other fruits or juices or Jamsetta to make a firm setting jam.Testing for setting point in jams

Keep a small stack of saucers in the freezer. You do this so as to get the hot jam to cool quickly to room temperature to show you whether it has set or is still very runny. Take a teaspoon of the jam while cooking and place it on the cold saucer. Put it back in the freezer for one minute and then take it out. (In the meantime, turn off the cooking so that it doesn’t continue while you’re waiting for your test). Run your finger through the jam and see if it stays apart or oozes back to the centre. If it stays apart the jam is set. If not, continue cooking and then check again soon after.If you are satisfied with the set, leave the jam for a few minutes before bottling. This helps distribute the fruit in the jam so that it doesn’t all rise to the top.

Hot jam goes into hot sterilised jars and then seal immediately. Once sealed, tip the jars upside down for several minutes as this aids the vacuum sealing process and also helps sterilise the lids. To increase the shelf-life of jams, you may also want to heat process (see page 3) them to help them keep (unopened) for up to 2 years. Otherwise, 6-12 months is the maximum recommended storing time of unopened jams, especially if you lowered the amount of sugar in the jam.Small amounts, small batches, small jars are best

Best results come from making small batches at a time. Do not use more than 2 kg at a time of combined fruit and sugar. The shorter cooking time will result in better texture, appearance and importantly, flavour. Wide open saucepans are also better for faster cooking. Of course,when bottling jams, small jars are better than large ones, as jams start to spoil as soon as they are opened, even when refrigerated.

Pickling Using Vinegars

Many vegetables can be preserved by pickling in vinegar, where the acid content of the liquid prevents spoiling of the food. However, note that you need a minimum vinegar content of 50% in the pickling liquid in order to prevent botulism in low acid vegetables. There are usually two stages to the pickling process.

Stage 1: Vegetables are salted to draw out excess moisture. This is either in a brine (salt in water) solution or dry salted. This is kept up to overnight in a cool place and then the resulting liquid drained off and the vegetables rinsed the next day. (Some low water vegies, such as beetroot, radishes and cauliflower can skip this pre-salting step).

Stage 2: The vinegar is boiled briefly with flavourings, such as chilli, bay leaves, peppercorns and mustard seeds. The vegetables are then covered with the (strained) vinegar in the sterile jars. For crunchy pickles, you will need to allow the vinegar to cool before pouring. For softer pickles, use the vinegar still hot. Sometimes recipes will have a weaker acid solution but make up for that by using a vinegar/brine solution. Other recipes, particularly ones with a Mediterranean influence, use both brine and vinegar to prepare the vegies. These are then squeezed out of them and the pickled vegies then stored under olive oil. This means that excess moisture has been removed AND air excluded by using the oil.