A pressure cooker. This is a useful addition to the home preservers kitchen and instructions for their use can be found under Marmalade.
A freezer.
JARS, CONTAINERS AND LIDS
Clean, dry, sterilised jars and bottles are suitable for the majority of preserves. Domestic jars, ie jam jars, honey pots, sauce bottles, etc. are accustomed to some heat, but you must make sure that you thoroughly wash and sterilise the jar by heating first. Always use glass bottles with a cork or plastic top to avoid leaving a taint on the finished product, and use a narrow funnel for pouring.
A word about jar sizes. When you come to fill your jam jars you will realise that the British 1lb/450g jar has evolved into a 13oz/375g size. It is difficult to judge exactly how many jars you will need since much depends on the type of fruit or vegetables used and the cooking time. Big, bulky fruit with a high pectin content, like apples, will fill more jars than a shrinking fruit with little pectin content, such as strawberries. Jam containing commercial pectin will give you jam for your money. Chutney and pickles vary considerably depending on the amount of liquid used and the thickness required. It is always wiser to use very small jars or pots (baby food jars are excellent) for more unusual preserves such as herb jellies, which may not be eaten very quickly and may deteriorate once opened. Therefore, you may take it that an ordinary jam jar referred to is the conventional 375g, a medium jar is 175g and a small jar is approximately 50–75g. Large jars, generally speaking, hold 900g.
Jars can be sealed with wax discs and paper or small rounds of pretty material or paper doilies tied down with string, which is a very attractive option for giving as presents. Screw-top lids can be used to seal any preserve that does not contain vinegar as vinegar corrodes metal and not only makes a nasty mess, but renders the contents unobtainable. However, many jar and bottle caps are now plastic lined.
Strictly speaking, corks should not be used in herb vinegars as they tend to draw out flavour, although many corks are now made from plastic. If in doubt, make a tight twist of greaseproof paper around the bottom of the cork. Bottle corks may be obtained from ironmongers. Make sure that they are clean and dry before using.
When potting with Kilner or preserving jars, always use new bands and the lids and screw or clip seals provided with the jars. An old-fashioned and very competent way of sealing preserves is to pour a thin layer of paraffin wax over the contents, but this has its disadvantages: the preserve must be really thick and well set and besides, it is a very fiddly business.
Some of the recipes for pickles refer to the use of earthenware jars. Although earthenware jars are the traditional containers for pickled fruits and fruits in alcohol, certain facts must be established. First, do make sure that the container is fully glazed and non-porous, otherwise your lovely juice will disappear. Secondly, if it is glazed, it must not be a lead glaze. Lead reacts against vinegar, alcohol and certain fruit with a high acid content to become potentially lethal. Those attractive old-fashioned earthenware containers picked up at car-boot sales and second-hand shops may be lead glazed for in Britain and on the Continent this was predominantly used in the past. Scandinavian countries favoured a borax or salt glaze and these are the ones most frequently used nowadays. A rough guide is in the appearance: borax and salt glazes are usually of a speckled grey stone. Nowadays those highly decorative rumtopf and pickle jars, which have been made specifically for those purposes, one would assume to be safe, but if you are not sure, do not use them.
Clean and polish your containers after you have filled them, label them clearly with the contents and date and store them in a cool dry place away from bright lights, damp, steam and well off concrete floors. Now you can sit back, quite smugly, and enjoy the sight of rows of glowing, glistening and glorious preserves, which are the fruits of your imagination, hard work and labour.
TO STERILISE GLASS BOTTLES OR JARS BEFORE FILLING
Preheat the oven to 120°C/gas mark ½. Wash the bottles or jars and lids in very hot soapy water, rinse and then place in a roasting tray. Pour boiling water into the jars and bottles and over the lids. Discard the water and then place the tray in the preheated oven for 15 minutes. The bottles or jars and lids are then ready to use.
If you put a cold glass jar straight into a hot oven or boiling water it will crack. The same applies to transferring hot jars full of hot preserve on to a cold surface, so lay a wooden board or thick cloth where you intend to place the jars. Decorative glass jars are a different thing and should be carefully tested for their strength before filling with a hot preserve.
TO STERILISE FILLED JARS
This process is used for the final stages of all the sauce, purée and paste recipes. The jars to use for preserves that need sterilising after potting are the four-piece preserving jars with rubber bands, glass lids, screw or clip tops. Before you start cooking your fruit take your clean, dry jars and pop them into a cool oven and bring the heat up to 140°C/gas mark 1. Put the tops of the jars to boil for 10 minutes, bringing the heat up from cold. Just before they are done, drop the rubber bands in as well.
Pour the boiling preserve into the jars. Put on the rubber bands and the tops. Fasten the tops of the jars with screw lids or clips. When using screw lids, give a bare half turn back again to allow for the expansion of the jars. Put a wire rack or false bottom in a preserving pan. Stand the jars in the receptacle, making sure that they do not touch and fill the container with very hot water. Bring to the boil and boil for 5–8 minutes or however long is specified in the recipe. Remove the jars and place on a wooden board or thick cloth. Tighten the screw tops immediately.
Test after 24 hours by removing the clip or screw band – you should be able to lift the jar by the glass tops. If the jar does not fall off, then the seal is complete. If it does fall off, then you will either have to scrape the contents from the floor or eat it within the next few days. This principal is the same as that for bottling fruit and vegetables. Asparagus pans, tall and narrow, are excellent for sterilising bottles.
STORING PRESERVES
As the reason for making preserves is in order to put produce by for another day, it would be expected that jams, preserves, chutneys, sauces and pickles, etc. should last for at least 6 months if they have been made and potted correctly, and most probably longer. Use within a year to be absolutely certain.
Most preserves, unless specifically stated otherwise, can be eaten as soon as they are cooled – usually the next day.
Some preserves, like lemon curd which has eggs and butter in it, are better kept in the fridge once opened.
Chutney will shrink quite considerably over time as it thickens on keeping, so make sure the jar is well filled.
WHAT WENT WRONG?
Nothing can make the keen home preserver weep more copiously than the discovery that all of those glorious well-made pots have ‘gone off’. The waste of time, effort and money is very defeating, but all is not lost. The least problematic is a little growth of fluffy mould on the top of sweet preserves and I am assured that providing the product is homemade, does not smell ‘winey’ or fermenting and has no other discernible bad smell or look, this can be removed. Clean the lid and dry, then replace, keep in the fridge and consume the preserve quickly. I speak from experience.
However, it is so much better to avoid these problems from the start. Apart from problems such as the incorrect use of sugar, fermenting caused by overripe or bruised fruit, or poor colour due to the wrong pan being used, the most common problem of storing jam is that of a mould forming on top.
The most likely cause is an oversight during the potting process. Jars must be scrupulously dried, sterilised