Not all fruits can be made in to jelly. Only those that have flavor and a substance called pectin can be transformed into delicious jelly, such as the bignay fruit, papaya, duhat, santol, tamarind and guava. Soursop (guayabano) sininguelas, breadfruit(rimas), anonas and chico all have high pectin content.
Testing Fruit for Pectin
To determine whether a certain fruit can be successfully made into jelly, boil a small amount of its juice with sugar. If it gels, then it is rich in pectin.
You can also test using 95 per cent denatured wood alcohol. Mix two tablespoon of this with one tablespoon of fruit juice. If transparent, jelly-like lump is formed, then the fruit can be successfully be transformed in to jelly. Make sure that the gel formed is firm and does not dissolve easily.
Another test for pectin content makes use of a jelmeter. This is an instrument similar to pipette, where the fruit juice is allowed to run down the tube. Observe the juice, whether it is thick enough and runs down the tube slowly.
Testing Fruit for Acid Contents
Fruit have to be made into jelly should also have the right acidity-pH 3.4. To test this acidity, mix one tablespoon of kalamansi juice and eight tablespoon (1/2 cup ) of water. Compare its taste with that of the fruit juice. The fruit juice has high acid content if it taste as sour as the kalamansi juice. You may increase the fruit juice’s acidity by adding kalamansi, lemon juice, or commercial citric.
Preparing the Fruit
To make jelly, select and mix together both ripe and slightly underripe fruit. Do not choose overripe, nor green immature fruit as these do not have enough flavor.
Wash the fruit thoroughly in cold running water, then crush, grind or chop into fine pieces. Place them in a large kettle then add just enough water to immerse the mashed fruit. Juicy or watery fruit will only need about 1/2 cup of water per kilo of fruit. Add kalamansi, etc., if the fruit is known to have low acid content.
Boiling and Extracting the Juice
Boil the fruit low heat until the flesh becomes tender. Soft fruit may be boiled for only three minutes, while firmer fruit require a longer period. Dot not overcook as this will reduce the jelly’s quality.
Transfer the cook pulp with the juice into a damp jelly bag. This may be a clean piece of cheesecloth made into baglike strainer. Allow the juice to drain completely, then twist and press the bag just hard enough to squeeze out the juice. Afterwards, strain the extracted juice again through a damp cheesecloth with double thickness. Do not squeeze this time in order to acquire the purest juice.
Fruits rich in pectin and juice can be extracted twice. After juice has been removed the first time, return the pulp to the kettle, add enough water, then boil again. Drain and mix the juice with the previously extracted one.
Cooking the Jelly
Test the fruit juice again for acidity and pectin content. Measure the juice in cups, then prepare one cup of sugar for every cup of juice that is rich in pectin. For fruit with only a moderate amount of pectin, prepare 3/4 cup of sugar for every cup of juice. If the juice is pale in color, add sugar before cooking, otherwise, add sugar after it has been boiled.
Cook no more than two cups of juice at a time. Keep the kettle covered and bring to a boil as fast as possible without stirring. When large bubbles form that tend to” jump out” of the pan, you may remove the kettle from heat.
In a saucer with water, pour a small amount of boiling syrup. If the syrup from a soft ball which crinkles when pushed with a finger, and retains its shape when lifted out of the water, then the jelly has been cooked sufficient. You may also test by just putting a small amount of the boiling syrup into a saucer and observing whether the syrups forms into a gel.
Another way to test the “jellying point” is to dip a wooden spoon into the boiling jelly. The jelly has been cooked sufficiently if it sets on the spoon and falls off as one sheet of flake. Boiling temperature has to reach 119.5° to 222°F for the jelly to be cooked just right.
Finishing the Jelly
Remove the kettle from the heat immediately after the jelly has been cooked well enough. Remove the scum or impurities by drawing a clean piece of paper across the surface of the jelly. You can also strain the jelly through two layers of sinamay cloth.
Pour the jelly at once into a warm jars, leaving 1/2-inch allowance from the top. Set aside to cool undisturbed. Before the jellycools completely, pour melted paraffin 1/8-inch thick to cover the surface, or just place waxed tissue to seal the top completely. Use vacuum sealing, if possible.
Store jelly in cool, dark and dry places.
Ingredients to be Used to Transform Some Fruits into Jelly
- Bignay 3/4 -1 cup of sugar per cup Ripe of juice
- Papaya 3/4 -1 cup of sugar per cup Slightly underripe of juice
- 2 tablespoons kalamansi juice per cup of juice
- 1 tablespoon kalamansi juice per 2 cups of fruit
- Duhat 3/4 -1 cup sugar per cup Ripe of juice
- 1 tablespoon kalamansi per cup of juice
- Tamarind 3/4 -1 cup of sugar per cup Ripe of juice (Soak overnight in water before cooking. Boil for 15 minutes.)
- Guava 3/4 -1 cup sugar per cup of Mixed green and ripe juice fruits
- 1 tablespoon kalamansi juice per cup of juice
For more information, contact:
Dept. of Science and Technology
Rm. 303 DOST Bldg., DOST Complex,
Gen. Santos Ave., Bicutan, Taguig City 1631
Telephone Nos: (632) 837-20-71 to 82
source: dost.gov.ph, photo from wikipedia.org