Fully ripe watermelons that have a soft red flesh should be used for making jelly. The juice is extracted from the fruit and used to make a jelly, rather than a jam (jams contain pieces of fruit pulp whereas jellies are made from fruit juice). Watermelons contain little natural pectin so pectin has to be added to ensure the jelly will have a good set. Other fruits that are high in pectin, for example apple, rind of passion fruit, can be mixed with the watermelon juice if commercial pectin is not available. Watermelon juice is not very acidic (pH above 5.0) which is too high to make a good jam or jelly. Jams give a gel when there is the correct ratio of pectin to water and the pH is between 2.5 and 3.45 pH. The optimum pH to give a good gel is pH 3.0. Therefore citric acid has to be added to the recipe to reduce the pH and increase the acidity of the juice. The yield of usable fruit from the whole fruit is approximately 43%.
Figure 1: Three glass jam jars of Water melon Preserves by Issraa El-Kogali, Sudan
Fruit juice Sugar Green ginger Pectin Citric acid 74% (starting recipe 55% before boiling) 0.8% 0.4% 0.7%
Wash whole fruit in clean water and discard any bad part of the fruit. Remove the skin from the melon, cut the flesh into small pi eces and remove the seeds. Mash the pieces into a pulp and strain through a muslin cloth. Mix the pectin with a small portion of the sugar. This dry mixing of the pectin is important because pectin powder is very difficult to dissolve in water because i t clumps together. If it is still a problem to dissolve, grind the sugar to a fine powder and then mix it with the pectin.
Practical Action, The Schumacher Centre, Bourton on Dunsmore, Rugby, Warwickshire, CV23 9QZ, UK T +44 (0)1926 634400 | F +44 (0)1926 634401 | E firstname.lastname@example.org | W www.practicalaction.org ___________________________________________________________________________________________________________ Practical Action is a registered charity and company limited by guarantee. Company Reg. No. 871954, England | Reg. Charity No.247257 | VAT No. 880 9924 76 | Patron HRH The Prince of Wales, KG, KT, GCB
Mix the fruit juice, sugar, citric acid and green ginger in a stainless steel saucepan and start boiling the mixture. Near the end of the boiling process the pectin dry mix can be added. (The pectin should not be heated for longer than necessary because it will be broken down and then the jelly will not set.) The jelly should not be boiled for more than 12 -15 minutes as this can give rise to caramel flavours, over sweetness and discolouration, apart from being a waste of energy. By reducing the amount of water in the starting recipe the boiling time can be reduced.
Boiling to reach the final sugar concentration
The aim of boiling is to reduce the water content of the mixture and concentrate the fruit and sugar in as short a time as possible. The final Total Soluble Solids (TSS) content of a jelly (also known as the “Degrees Brix” or “end-point of the jelly”) should be 65 to 68% (the TSS is a measure of the amount of material that is soluble in water. It is expressed as a percentage -a product with 100% soluble solids, has no water and one with 0% soluble solids is all water). The correct sugar content is critical for proper gel form ation and for preservation of the jelly. If the final TSS of jelly is lower than 65-68%, the shelf life will be reduced. The jelly will have a runny consistency and bacteria and moulds will be able to grow in the product. If the TSS is higher than 68%, the jelly will be very stiff and the sugar might form crystals during storage. The end-point of boiling is measured in different ways. The most accurate method is to use a refractometer to measure the total sugar concentration. Remove the pan from the he at during testing as the jelly will continue to cook and may become over-cooked. It is always possible to cook the mixture a little bit more, but once it is over-cooked (and too thick) it cannot be reversed. Cool the sample before it is measured by smearing it on a cold dry plate or saucepan lid. All implements used to take the sample must be dry otherwise the reading will be reduced. It is important to stir the jelly at all times during heating, otherwise it may burn at the bottom of the saucepan, causing off flavours and discoloration. This method is not really suitable for home-use as a refractometer costs about US$ 150. It is only when making jelly for sale that a refractometer is necessary, to ensure consistency between different batches of the jelly. When making jam or jelly for home consumption, other methods can be used to determine the end point: these include the drop test, the skin wrinkle test, or the use of a jam thermometer to test the temperature (68% sugar corresponds to a jam temperature of 105°C). When the jelly starts to thicken, it is important to test for the end point at frequent intervals. Remember to remove the pan from the heat source while you test or it will continue to thicken and may burn.
Filling into jars, cooling and l abelling
Wash and sterilise the glass jars and lids by placing in a pan of water and boiling for 10 minutes. Remove the jars from the water with a pair of tongs and stand upside down to drain. Do not dry with a towel as this could contaminate the jars. If glass jars are not available, use plastic jars. These cannot be sterilised with boiling water as they will melt. They should be thoroughly cleaned in warm soapy water and rinsed with a weak solution of sodium metabisulphite. Sterilising tablets (made o f sodium metabisulphite) can be bought for this purpose. Allow the jelly to cool slightly (to about 80°C for glass jars and 60°C for plastic jars) and then pour it into clean, sterilised jars. The jars should still be warm to prevent them from cracking when the hot jelly is poured in. If the jelly is cooled too much it will be difficult to pour. Place the clean lids on top and fasten. Invert the jars to form a seal. The filled jars can be
placed in water to cool down the jelly so that it does not keep cooking in the jar. The water should not be too cold or the glass may crack. Also, the water level must be kept below the lid of the jar. The gel starts to form as the temperature of the jelly reduces (about 55°C) and continues until it is cold. The jars should not be moved or shaken while they are cooling or the gel will not form and the jelly will not set.
Jam and jelly that is hygienically prepared, boiled until it reaches the correct final total soluble solids (68%) and which is packaged in sterilised glass jars can be stored for up to a year so long as it is kept in a cool place away from direct sunlight. Jam or jelly that is packaged in plastic containers has a shorter shelf life – up to 4 months.
Glass jars, Omnia lids and labels Omnia capper Cooking facilities, gas ring, electric ring, etc Stainless steel saucepan Thermometer in protective jacket Stainless steel cutting knife and spoon Wooden spoon for stirring Refractometer Cutting board Scales Liquidiser or mashing tool
Note: This is a selective list of suppliers and does not imply endorsement by Practical Action
Cutting and slicing equipment
A range of manual and powered cutting and slicing machinery is available. Eastend Engineering Company 173/1 Gopal Lal Thakur Road Calcutta 700 035 India Tel: +91 33 2553 6397 Gardners Corporation 158 Golf Links New Delhi 110003 India Tel: +91 11 2334 4287/2336 3640 Fax: +91 11 2371 7179 Narangs Corporation P-25 Connaught Place New Delhi 110001 India Tel: +91 11 2336 3547 Fax: +91 11 2374 6705
It is important to have accurate weighing machines. Quite often more than one machine is required - -a large one to weigh the fruit and a small one for weighing out the dry ingredients such as pectin and spices. Fisher Scientific Bishop Meadow Road Loughborough LE11 5RG UK Tel: +44 1509 231166 Fax: +44 1509 231893 Email: email@example.com Web: www.fisher.co.uk Essae-Teraoka Ltd 377/22 6th Cross Wilson Garden Bangalore 560027 India Tel: =91 80 2216185/2241165
Gardners Corporation India (see above) Narangs Corporation India (see above)
Juice extractors and pulpers
A variety of juice extractors and pulpers is available from a wide range of suppliers. They are available in different capacities and either manual or powered (either electric or diesel). Kenwood Limited New Lane Havant Hampshire PO9 2NH United Kingdom Tel: +44 (0) 23 9247 6000 Fax: +44 (0) 23 9239 2400 Website: http://www.kenwood.co.uk Lehman Hardware and Appliances Inc. P.O. Box 41 Kidron Ohio 44636 USA Tel orders: +1 877 438 5346 Tel enquiries: +1 888 438 5346 E-mail: firstname.lastname@example.org Website: http://www.lehmans.com Eastend Engineering Company India (see above)+ Robot Coupe 12 Avenue Cal Leclerc BP 134 71303 Montceau-les-Mines France Tel: +33 3 85 58 80 80 DISEG (Diseno Industrial y Servicios Generales) Av Jose Carlos Mariategui 1256 Villa Maria del Triunfo Lima Peru Tel: +51 14 283 1417 Servifabri SA JR Alberto Aberd No. 400 Urb Miguel Grau (ex Pinote) San Martin de Porres Lima Peru Tel: +51 14 481 1967 Bajaj Machine Private Limited 7/20, 7/27, Jai Lakshmi Industrial Estate, Side-IV Sahibabad Industrial Area Ghaziabad-201301 U.P India Tel: +91 120 22775119/22775137 Fax: +91 120 22775137 Website: www.indiamart.com/bajajmachine Florachem Flat No. 1119, Hemkunt Chambers, 89, Nehru Place New Delhi 110019 India Tel: +91 11 25589502 Gardners Corporation India (see above)
Food Packs Indiana Thrikkariyoor, Kothamangalam, Ernakulam Kerala 686692 India Tel: +91 485-2522134, 2523610
Geeta Food Engineering Plot No C-7/1 TTC Area Pawana MIDC Thane Belapur Road BehindDavita Chemicals Ltd Navi Mumbai 400 705 India Tel: +91 22 2782 6626/2766 2098 Fax: +91 22 2782 6337
Buhler (India) Pvt Ltd 13-D, K A I D B Industrial Area, Attibele Bangalore Karnataka 562107 India Tel: +91 80- 27820000 Fax: +91 80-7820001 Website: www.buhlergroup.com Delhi Industries 4 Paharganj Lane, New Delhi 110055 India Tel: +91 11 2529720, 27525200, 27536888 Fax: +91 11 25791291 Do-All-Engineering Industries 87/12, Industrial Suburb, Yeshawanthpur Bangalore Karnataka 560022 India Tel: +91 80 23345754, 23372298 Fax: +91 80 23346138 Udaya Industries Uda Aludeniya, Welligalla Gampola Sri Lanka Tel: +94 8 388586 Fax: +94 8 388909 Mark Industries (Pvt) Ltd 348/1 Dilu Road Mokbazar Dhaka 1000 Bangladesh Tel: +880 2 9331778/835629/835578 Fax: +880 2 842048 Email: email@example.com
Narangs Corporation India (see above)
Praj Industries Ltd Praj House Bavdhan Pune, Maharashtra 411021 India Tel: +91 20-22951511, 22952214 Fax: +91 20-22951511 / 22952214 Website: www.praj.net Techno Equipmen ts Saraswati Sadan 1st Floor, 31 Parekh Street Mumbai 400004 India Tel: +91 22 2385 1258 Kundasala Engineers Digana Road Kundasala Kandy Sri Lanka Tel: +94 8 420482
Boiling pans should be made of aluminium, enamelled metal or stainless steel. For larger quantities it is necessary to buy equipment which does not cause burning or sticking of the product to the bottom of the pan. Stainless steel steam jacketed kettles, which are double walled pans are suitable for boiling large quantities of jam and are available in a range of sizes (from 5 to 500litres). Gardners Corporation India (See above) )