An Introduction to Jam Making and Preserving
A fresh-tasting, tangy marmalade or fruit packed conserve, thickly spread on hot, buttered toast, is a delicious way to start the day. No ploughman’s lunch, cold meat platter or pork pie is complete without a good helping of chutney or a spoonful of pickle. In spite of the vast assortment of commercially-prepared preserves now available, none can compare with those made at home.
This article is presented in such a way as to be a mini course in the subject of preserving. Once you have understood the basics of making jam and other preserves you can use the links to go the recipes and make your own favourites.
The making of preserves was once an important and regular feature of life; every household had a cupboard stacked with jars full of preserved foods. Nowadays, the increasing availability of fresh foods all year round, and of commercially-prepared preserves, means that the art of home preserving is sadly neglected.
In this article we hope to reintroduce you to those age-old skills which were once so lovingly practised. Here you will find all the classics: jams, jellies, pickles and chutneys, along with lots of new ideas for herb oils and vinegars, drinks, liqueurs, sauces and relishes, plus information on home bottling, salting, storing and drying.
Why Preserve?
The object of preserving is to take fresh foods in prime condition and to store or prepare them in such a way that they remain in this condition for long periods of time. In the days before refrigeration and easily obtainable canned, dried and frozen foods, it was vital to be able to preserve fresh foods to feed the family when food was scarce. In country areas, each family kept a pig to fatten up during the summer and slaughter at the beginning of winter. Some meat was eaten fresh but the bulk of it had to be preserved in various ways so that it would last throughout the winter. Fresh fruits and vegetables were made into preserves both to prevent wastage and to enable people to enjoy their flavour when they were not available.
Although the necessity for preserving does not exist in quite the same way today, one of the most important benefits is still that of saving money. jams, jellies and marmalades are best made when fruits are plentiful, cheap and in perfect condition. Despite their high cost, the quality of commercially-produced preserves is rarely as good as that of home-made preserves. For example, fruits and vegetables can lose more of their nutritive value during commercial processing. Making preserves at home enables you to experiment with unusual combinations of flavours and to enjoy the satisfaction of serving foods that are the produce of your own kitchen. An added bonus is that some preserves, such as candied or crystallised fruits, make very acceptable gifts when decoratively packed.
How Preserving Works
Foods contain enzymes which are responsible for their growth, development and eventual breaking down and rotting. The action of these enzymes is what causes the cut surface of a piece of fruit to turn brown, for example, and allows for the growth of micro-organisms in the form of bacteria, yeasts and moulds. Bacteria in foods can lead to food poisoning, yeasts cause foods to ferment, and moulds spoil the appearance and flavour of foods. Moulds themselves are not harmful, but are often an indication of the presence of bacteria.
Traditional forms of preserving aim to keep out and prevent the growth of micro-organisms and so maintain the food in prime condition. The first methods of preservation were probably the result of experimentation and a fair amount of luck, but nowadays we know how and why these methods worked. They made use of natural facilities — sun, wind, smoke and salt.
Drying: lt was discovered that when foods were spread out in the sun or hung in the wind to dry, they did not perish. This is because micro-organisms can only survive where there is moisture and the drying effects of sunshine and wind prevent the growth of micro-organisms. Nowadays, fruits, vegetables and herbs can easily be dried at home in a very cool oven, airing cupboard or some other warm place. Of course, it is always important to store dried foods carefully to prevent the re-absorption of moisture.
Smoking: When houses had huge fireplaces and chimneys, meat and fish could be hung in the chimneys until well dried out and ‘smoked’. Again, it was the drying process that prevented the growth of bacteria. The flavour of the smoked foods would depend on the type of wood burned in the fire. Nowadays, such facilities for smoking are hard to find and smoking is rarely done in the home. It can also be dangerous if not carried out properly and if the growth of bacteria is not completely eliminated. Commercially-smoked foods are of good quality, if rather expensive, and some, such as smoked salmon, may even be preferred to the fresh variety.Because of the facilities needed, the risk of food poisoning and the availability of commercially-produced smoked foods, we do not recommend smoking as a method of home preserving today.
Salting: In early days, sea salt was obtained by evaporation and rubbed into fish, meat and vegetables. The salt drew moisture out of the food and prevented the growth of micro-organisms. The salting of meat, however, is another method of preservation that can be dangerous if not carried out correctly. As fresh meat is now available all year round and can be preserved in other safer and more efficient ways, such as by freezing, we have not included instructions for salting or curing meat in this article. Small fish, such as anchovies or sprats, and vegetables, such as beans, can, however, be salted in the home without too much trouble. These original methods of preservation were used long before it was discovered that sugar, vinegar, alcohol and temperature could also play a part.
Sugar: A high concentration of sugar prevents the growth of micro-organisms and it is the sugar, combined with cooking to a high temperature, which preserves the fruits in jams, jellies, marmalades, conserves, butters and cheeses. Sugar also acts as the preservative when bottling fruits in a sugar syrup. Again, however, it is necessary to heat the filled bottles to a high temperature in order to sterilise the contents and hermetically seal the bottles to prevent further attack from micro-organisms.
Vinegar and alcohol: Vinegar and alcohol also prevent the growth of micro-organisms. Vinegar is used for pickling fruits and vegetables, and in chutneys, sauces and relishes; alcohol is used to preserve fruits.
Sterilisation: Extremely high temperatures stop enzyme activity and prevent growth of micro-organisms. Sauces, ketchups and bottled fruits and vegetables all need to be sterilised by heat. This has to be done after the bottles have been filled and covered so that the sterilising process can form a seal to keep out micro-organisms in the air. Milk is commercially sterilised by heat treatment during the pasteurisation process and some milk is heated to a higher temperature (‘long-life’ or UHT —ultra-high temperature) and can be kept for long periods of time without being refrigerated.
Refrigeration and freezing : The discovery that low temperatures slow down or stop enzyme activity in foods has made a major difference to life in the home. Nowadays, almost every household has a refrigerator and many also own a freezer. Foods are kept at a sufficiently low temperature to stop the action of enzymes. Although freezing is a method of home preserving, it is not one of the traditional home skills, so we have not included instructions for freezing in this article.
Jam is basically a cooked mixture of fruit and sugar. The high concentration of sugar used in jam-making prevents the growth of micro-organisms and allows the jam to be kept for many months.
Conserves are whole, sometimes chopped, fruits suspended in a thick syrup. In most cases, to make a conserve, the fruit is layered with an equal quantity of sugar and left for 24 hours to extract the juices, before boiling for a short time, preserving the fruit with the minimum of cooking. Fruits which make good conserves are strawberries, raspberries and loganberries. The fruits retain a flavour which is very much closer to the original taste of the fruit. Conserves make the most acceptable gifts or excellent desserts when served with cream, fromage frais or Greek yogurt.
Equipment
Some special utensils and tools, though by no means essential, make making jams and conserves easier. Preserving pans jams and conserves can be made in any heavy-based saucepan large enough to ensure that the contents come only halfway up the side once the sugar has been added. Proper preserving pans do make life easier, however, as their sloping sides help the jam to maintain a ‘fast rolling boil’ without boiling over. This is essential for a good set. Choose a preserving pan made from stainless steel, tin-lined copper or lined aluminium. It should have a fairly thick base to prevent the jam burning, and should be wide enough to allow the jam to boil rapidly without splashing all over the hob. The best size for you will depend on how much jam you want to make at one time.
Old-style preserving pans made from unlined copper or brass can be used for jams, providing they are perfectly clean, but it is unwise to use very old pans that are damaged or impossible to clean thoroughly. Any discoloration or tarnish should be removed with a patent cleaner and the pan should be thoroughly washed before use. Jams made in copper or brass pans will contain less vitamin C than those made in aluminium or stainless steel pans. No preserve should be left standing in any unlined metal preserving pan.
If you haven’t got a preserving pan, use a large heavy-based saucepan, remembering that, since most saucepans are not as wide as a preserving pan, you may need to allow a longer simmering and boiling period for the fruit.
Jam jars: You will need a good supply of jars, which should be free from cracks, chips or other flaws. jars holding 450 g or 1 kg (1 or 2 lb) are the most useful sizes as you can buy covers for these sizes. Wash them well in warm soapy water and rinse thoroughly in clean, warm water. Dry off the jars in a cool oven, at 140°C (275°F) mark 1, and use while hot so that they do not crack when filled with boiling jam. You will need waxed discs, cellophane covers, rubber bands and labels for covering and labelling the jars. Packets containing all these are available from most stationery shops, cookshops and some chemists.
Other equipment
1. A large, long-handled wooden spoon for stirring the preserve.
2. A slotted spoon is useful for skimming off any scum or fruit stones from the surface of the
preserve.
3. A sugar thermometer, though not essential, is very helpful when testing for a set.
4. A funnel with a wide tube for filling jars is useful. Failing this, use a heatproof jug or large cup.
5. A cherry stoner saves time and prevents hands becoming stained with cherry juice.
6. Any sieve used in jam-making should be made of nylon, not metal, which may discolour the fruit.
Choosing the fruit
Fruit should be sound and just ripe. It is better to use slightly under- rather than over-ripe fruit as the pectin is most readily available at this stage.
Pectin and acid content of fruit: The preserve will only set if there are sufficient quantities of pectin, acid and sugar present. Some fruits are rich in pectin and acid and give a good set, while others do not contain so much (see chart below).
Pectin Content of Fruits and Vegetables used in Preserving
Good Medium Poor
Cooking apples Dessert apples Bananas
Crab-apples Apricots Carrots
Cranberries Bilberries Cherries
Currants Blackberries Elderberries
Cranberries Figs
Damsons Greengages Grapes
Gooseberries Loganberries japonicas
Lemons Mulberries Marrows
Limes Plums Medlars
Seville oranges Raspberries Melons
Plums Nectarines Peaches
Quinces Pineapple Rhubarb
Strawberries
Testing for pectin content: If you are not sure of the setting qualities of the fruit you are using, the following test can be carried out: When the fruit has been cooked until soft and before you add the sugar, take 5 ml (1 tsp) juice, as free as possible from seeds and skin, put it in a glass and, when cool, add 15 ml (1 tbsp) methylated spirits. Shake the glass and then leave for 1 minute. If the mixture forms a jelly-like clot, the fruit has a good pectin content. If it does not form a single, firm clot, the pectin content is low and some form of extra pectin will be needed.
Fruits that lack acid and pectin require the addition of a fruit or fruit juice that is rich in these substances. Lemon juice is most often used for this purpose, since it aids the set and often brings out the flavour of the fruit. Allow 30 ml (2 tbsp) lemon juice to 1.8 kg (4lb) of a fruit with poor setting properties. Alternatively, use Sugar with Pectin or some home-made pectin extract (see below) or add another pectin-rich fruit, making a mixed fruit jam. Yet another method is to use a commercially-bottled pectin according to the manufacturer’s instructions.
Sometimes an acid only is added, such as citric or tartaric acid. These contain no pectin but help to extract the natural pectin from the tissues of the fruit and improve the favour of fruits lacking in acid. Allow 2.5 ml (1/2 tsp) to 1.8 kg (4 lb) of fruit with poor setting properties.
Home-made pectin extract: Apple pectin extract can be made from any sour cooking apples or crab-apples as well as from apple peelings and cores and windfalls. Wash 900 g (2 lb) fruit and chop it roughly, without peeling or coring. Cover with 600-900 ml (1—1 ½ pints) water and stew gently for about 45 minutes, until well pulped. Strain through a jelly bag or muslin cloth. Carry out the pectin test to ensure that the extract has a high pectin content. Allow 150-300 ml (1/4-1/2 pint) of this extract to 1.8 kg (4 lb) fruit that is low in pectin. Pectin extract can be made from redcurrants or gooseberries in the same way.
Sugar
The presence of sugar in jam is very important as it acts as a preservative and affects the setting quality. The exact amount of sugar to be used depends on the pectin strength of the fruit, so always use the amount specified in a recipe. Too little sugar will result in a poor set and the jam may go mouldy on storing. Too much sugar will produce a dark and sticky jam, the flavour will be lost and it may crystallise. Granulated sugar is suitable and the most economical for jam-making, but when lump sugar or preserving crystals are used, less scum is formed and the preserve needs less stirring to prevent burning, since these sugars do not settle in a dense layer on the bottom of the pan. The finished preserve will also be slightly clearer and brighter. Caster sugar or brown sugar can also be used, but brown sugar produces much darker jam with a changed flavour.
Sugar with Pectin is a blend of granulated sugar, natural apple pectin and tartaric acid and is very useful when making jams and conserves with fruits low in pectin. When using Sugar with Pectin, the best results are achieved if you follow these tips:
1. If using less than one packet of sugar, empty the whole packet into a bowl and stir it to distribute
the pectin, before adding the amount required to the fruit.
2. Do not use more than two packets of sugar at any one time.
3. Heat the preserve to a full rolling boil. The quoted boiling times apply after the boiling point
has been reached. A full rolling boil cannot be stirred down.
4. The usual boiling time for jam is 4 minutes.
Jams can also be made with fructose, a refined sugar produced from fruit and vegetables; as it is metabolised differently from ordinary sugar, diabetics may use it as a substitute, within reason. There is no completely satisfactory substitute for sugar in jam-making. If honey or treacle is used, its flavour is usually distinctly noticeable and the jam will not set easily. Glucose and glycerine do not have the same sweetening power as cane sugar. If one of these alternatives must be used, not more than half the amount of sugar specified in a recipe should be replaced.
You can make your own reduced-sugar jams similar to those you can buy. Do not reduce the sugar content by more than 20 per cent or the jam will be runny. As it does not keep well, make it in small batches and store in the refrigerator (for up to 6 weeks) or a cool place (for 3-4 weeks).
Preparing and Cooking the Fruit
Pick over the fruit, prepare it according to variety, and wash it quickly. Put the fruit into a preserving pan or large, strong saucepan, add water as directed in the recipe and then simmer gently until it is quite tender. The time will vary according to the fruit — tough-skinned fruit, such as gooseberries, blackcurrants or plums, will take 30-45 minutes.
This simmering process releases the pectin and acid. If extra acid or pectin is needed, it should be added at this stage. Adequate reduction of the fruit before adding the sugar is necessary for a good set. The sugar should only be added when the fruit has been sufficiently softened and reduced as sugar has a hardening effect on the fruit and, once added, the fruit will not soften. Remove the pan from the heat and add the sugar, stirring well until dissolved. (The sugar will dissolve more easily if warmed in the oven before it is added.) Add a knob of butter to reduce foaming, then return the pan to the heat and boil rapidly, stirring constantly, until the jam sets when tested.
Testing For a Set
There are several ways of testing a preserve for setting point, some of which are less accurate than others or require special equipment. The methods given here are the easiest to carry out and most accurate.
Temperature test: This is the most accurate method of testing for a set. Stir the jam and put in a sugar thermometer. Continue cooking and, when the temperature reaches 105°C (221°F), a set should be obtained. Some fruits may need a degree lower or higher than this, so it is a good idea to combine this test with one of the following.
Saucer test: Put a very little of the jam on a cold saucer or plate, allow it to cool, then push a finger gently through the jam. If the surface of the jam wrinkles, setting point has been reached. (The pan should be removed from the heat during the test or the jam may be over-boiled.
Flake test: Lift some jam out of the pan on a wooden spoon, let it cool a little and then allow it to drop back into the pan. If it has been boiled long enough, drops of jam will run together along the edge of the spoon and form flakes which will break off sharply.
Potting, Covering and Storing
The jars used for jam must be clean and free from flaws and they must be warmed before the jam is put in them (see page 9). As soon as a set has been reached, remove the pan from the heat, remove any scum with a slotted spoon and pot the jam, filling right to the tops. Exceptions are strawberry and other whole-fruit jams — these should be allowed to cool for about 15 minutes before being potted, to prevent the fruit rising in the jars. Wipe the outside and rims of the pots and cover the jam, while still very hot, with a waxed disc, waxed-side down, making sure it lies flat. Either cover immediately with a dampened cellophane round, securing with a rubber band or string, or leave the jam until quite cold before doing this. For long-term storage, cover the jam with a screw-top as well, but do not cover the pots when the jam is warm, as moisture from the warm jam will collect inside the lid and, without enough heat from the jam to kill the moulds, the preserve may go mouldy. Label the jar and store in a cool, dry, dark place.
Most preserves keep well for over a year if properly covered and stored, but their flavour deteriorates if they are kept for too long. The best idea, therefore, is to eat them within the year, thus making room in the store-cupboard for next year’s batch of preserves.
Mould: This is most often caused by failure to cover the jam with a waxed disc while it is still very hot — this should be done immediately the jam is potted, or it may become infected with mould spores from the air. Alternatively, the pots may have been damp or cold when used, or insufficiently filled, or they may have been stored in a damp or warm place. Other possible causes are insufficient evaporation of water while the fruit is being ‘broken down’ by the preliminary cooking, and/or too short boiling after the sugar has been added. Jam with mould growing on its surface should not be eaten, even if the affected jam is removed, as the mould can produce toxins within the remaining jam. Throw away the whole jar if you find any mould on the top surface.
Bubbles in the jam: Bubbles indicate fermentation, which is usually the result of too small a proportion of sugar in relation to fruit; accurate weighing of fruit and sugar is very important. This trouble can also occur, however, when jam is not reduced sufficiently, because this too affects the proportion of sugar in the preserve. Fermentation is harmless enough, but it is apt to spoil both flavour and colour. Fermented jam can be boiled up again but the boiling should only be continued for a short time if the preserve was not reduced enough in the first instance. It can then be re-potted and sealed in clean, preheated jars and used for cooking purposes.
Peel or fruit rising in the jam: Strawberry jam is particularly susceptible to this trouble. It helps if the jam is allowed to cool for 15-20 minutes and then given a stir before potting (despite the fact that it is normally advisable to pot all preserves as hot as possible).
Crystallised jam: This is usually caused by lack of sufficient acid. You should either use a fruit rich in acid, or make sure that acid is added to the fruit during the preliminary softening process. Under- or over-boiling the jam after the sugar has been added can also cause crystallising, as it will upset the proportion of sugar in the finished jam.
Setting problems: One cause is the use of over-ripe fruit in which the pectin has deteriorated. Another reason is under-boiling of the fruit, so that the pectin is not fully extracted; there may also be insufficient evaporation of the water before the sugar is added (this can be remedied by further boiling); or over-cooking after adding the sugar, for which there is no remedy.
To ensure a set with fruits deficient in pectin, such as strawberries, it is helpful to add an acid such as lemon juice or citric acid; alternatively, mix with a pectin-rich fruit such as redcurrants, or a pectin extract (commercially made or prepared at home from apples), or use Sugar with Pectin.
Shrinkage of jam on storage: This is caused by inadequate covering, or failure to store the jam in a cool, dark, dry place.
Pressure Cooking Jams
Provided your cooker is one with a three-pressure gauge, it is a good idea to use it for preserving, as it saves quite a bit of time and the fruit retains its flavour and colour.
There are a few points to remember:
1. Always remove the trivet from the pressure pan.
2. Never fill the pan more than half-full.
3. Cook the fruit at medium (10 lb) pressure. If you have a cooker which is set to cook only at high (15 lb) pressure, you can send for alternative weights (available from the manufacturer) which will enable you to alter your cooker to cook at medium (10 lb) pressure. Cooking preserves at high (15 lb) pressure is not recommended because the pectin will be destroyed.
4. Reduce pressure at room temperature.
5. Only the preliminary cooking and softening of the fruit must be done under pressure — never cook a preserve under pressure after adding the sugar (and lemon juice, if used), but boil it up in an open pan.
6. You can adapt any ordinary jam recipe for cooking in a pressure cooker by using half the stated amount of water and doing the preliminary cooking of the fruit under pressure. These are the times required for different fruits (all at medium/10 lb pressure):
Apples 5 minutes
Blackberries and apples combined 7 minutes
Blackcurrants 3-4 minutes
Damsons, plums and other stone fruit 5 minutes
Gooseberries 3 minutes
Marrow 1-2 minutes
Pears (cooking) 7 minutes
Quinces 5 minutes
7. Soft fruits, such as raspberries and strawberries, need very little preliminary softening and are therefore not usually cooked in a pressure cooker.
8. When two fruits (eg. blackberries and apples) are combined, the cooking times may vary somewhat.
Now you are ready to make your first batch of Jam Check out our recipes here -
Lemon Curd
Make your own Marmalade
Homemade Jam
Homemade Jellies
Homemade Pickles
Homemade chutney
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