Jelly is a mixture of fruit juice and sugar that is clear and firm enough to hold its shape.
Jam is made from crushed or chopped fruit. Jam holds its shape, but is less firm than jelly.
If you plan on making jams and jellies, or doing any canning at home you will need a good guide to help you along the way. I have used many recipes found on the recipe guide in the pectin container and Kerr canning pamphlet with great success.
The success of all jellies and jams depends on the balance of sugar, acid and pectin.
Pectin is what makes jam happen. It's a natural thickening substance found in many fruits like strawberries and apples, etc. Usually fruits that are slightly under ripe are highest in pectin. This is why many older recipes (ones that you don't add powdered or liquid commercial pectin) call for ripe fruit and under ripe fruit. Other fruits, like cherries and blueberries, contain little natural pectin. They must be mixed with other fruits high in pectin or with commercial pectin products for a gel to form.
The right amount of acid is critical to gel formation. With too little acid, the gel will never set. Too much acid will cause the gel to lose liquid (weep). If fruits are low in acid, add lemon juice or other acid ingredients as directed. Commercial pectin products contain enough acid to ensure gelling.
Use granulated or preserving sugar. Granulated is fine for high-pectin fruits. Preserving sugar is more expensive but will help set low-pectin fruits without the need to add lemon juice. Always make sure the sugar is completely dissolved before bringing to a boil. If not, the result will be grainy.
Always use undamaged fruit. Fruit with too much damage will spoil the result and the jam is likely to deteriorate quickly.
Don’t make too large a quantity at one time. Large volumes of fruit and sugar will take a long time to reach setting point causing the fruit to beak up and eventually dissolve in the jam. Generally it is suggested to use 1 to 2 cups of sugar for 2 cups of prepared fruit or fruit juice. The amount varies to the degree of set you want and to type of product - jellies, jam, preserves, conserves etc. you are making.
The amount of acid to add depends on the amount in the fruit you are using so check the sheet. Acidity is easily boosted by adding lemon juice to the fruit before cooking – about 2 tablespoons to 2 cups of prepared fruit or fruit juice. To determine the amount of pectin in your liquid put one teaspoon of the liquid on a plate and add 2 tablespoons of rubbing alcohol to the mix. Swirl the mixture around until clots start to form. It will amaze you but it will happen and you will know the strength of the pectin by the size of the clots. Basically you want a fairly large viscous clot to form to indicate strong pectin. Weak pectin count will show up as several small, scattered clumps. If that is the case, just bring the liquid back to the boil and reduce further. If you put a teaspoon of butter in cold juice before you boil jelly you will not have a scum on the jelly.
A vegetable brush is just the thing to remove scum from jelly. Jellies made from frozen berries are superior to those made from fresh fruit.
The freezing and thawing break down the cells of the fruit and allow the natural colors to dissolve in the juice. To economize on sugar when making jam, let the fruit boil for about 10 minutes before adding sugar. Only about 1/2 of the usual amount of sugar will be needed.
Temperature test — Use a jelly or candy thermometer, and boil until mixture reaches the following temperatures at altitudes of:
Sea level to 1,000 feet — 220 degrees F **** 1,001 feet to 2,000 feet — 218 degrees F
When the gelling point is reached, remove jelly from the heat and quickly skim off foam.
Use a wide-mouth funnel, and pour the jelly into sterilized jars. Leave 1/4-inch head space. Adjust lids and process as directed.
For the pectin to set you need both acid and sugar. This is why you can NOT deviate from the recipe in jam making.
Old fashioned recipes will ask you to cook the mixture to the "jam stage" which is when you spoon some mixture and let it slide off the spoon. If it is not done it will just run off, if it is cooked correctly it will slide off, but leave a "sheet" attached to the spoon.
Reliable Jelly Test: Dip a silver fork into the boiling jelly, and if it fills in between tall the tines of the fork the jelly is done. If not, cook a little longer until it fills in between the tines instead of dripping through , or In determining when the jellying point has been reached, place some of the jelly on a cold plate and draw a path through it with the point of a spoon. If the path stays without the jelly running together, the jellying point has been reached ; Always test for setting point at the time the recipe suggests, if not set continue to cook checking every 5 minutes.
Don’t overcook. It is tempting to keep cooking to achieve a firmer set. A slightly looser jam is preferable to one that tastes scorched or where the fruit has dissolved.
Too much sugar is the most frequent cause of jelly failure. Juice which does not have a tart taste is not acid enough and needs lemon juice added to it, about 1 tablespoon per cup of juice.
To Harden Jelly: After jelly glasses have been filled and allowed to cool and still the jelly has not hardened, place the glasses in a pan of cold water and set in the oven, allow them to cook until stiff .
What makes jelly cloudy? One or more of the following may cause cloudy jelly:
Pouring jelly mixture into glasses too slowly. Allowing jelly mixture to stand before it is poured.
Juice was not properly strained and so contained pulp. Jelly set too fast–usually the result of using too-green fruit.
What causes jelly to be too soft? One or more of the following may be the cause:
Too much juice in the mixture. Too little sugar. Mixture not acid enough. Making too big a batch at one time.
What makes jelly syrupy? Too little pectin, acid, or sugar. A great excess of sugar can also cause syrupy jelly.
What causes weeping jelly? Too much acid. Layer of paraffin too thick. Storage place was too warm or storage temperature fluctuated.
What makes jelly too stiff? Too much pectin (fruit was not ripe enough or too much added pectin was used). Overcooking.
What makes jelly tough? Mixture had to be cooked too long to reach jellying stage, a result of too little sugar.
What makes jelly gummy? Overcooking Commercially frozen and canned juices are low in natural pectins and make soft-textured sweet spreads. Use only in recipes calling for added pectin.
Paraffin or wax seals don't prevent mold growth and are no longer recommended for sealing any sweet spread, including jelly.
Overcooking jam and jelly can break down pectin and prevent proper gelling. Always make only one batch at a time. Making more than one batch at a time (doubling or tripling the recipe) often results in soft gels. Stir constantly while cooking to prevent burning. Remember that recipes are developed for specific jar sizes. Using larger jars may cause excessively soft sweet spreads.
Measure jelly to be recooked. Work with no more than 4 to 6 cups at a time. To remake with powdered pectin: For each quart of jelly, mix 1/4 cup sugar, 1/2 cup water, 2 tablespoons bottled lemon juice and 4 teaspoons powdered pectin. Bring to a boil while stirring. Add jelly and bring to a rolling boil over high heat, stirring constantly. Boil hard 1/2 minute. Remove from heat, quickly skim off foam and pour into sterilized jars. Leave 1/4-inch headspace. Adjust new lids and process the jars.
To remake with liquid pectin: For each quart of jelly, measure 3/4 cup sugar, 2 tablespoons bottled lemon juice, and 2 tablespoons liquid pectin. Bring jelly only to boil over high heat, while stirring. Remove from heat and quickly add the sugar, lemon juice, and pectin. Bring to full rolling boil, stirring constantly. Boil hard for 1 minute, then remove from heat. Quickly skim off foam and fill sterilized jars. Leave 1/4-inch headspace. Adjust new lids and process the jars .
To remake without added pectin: For each quart of jelly, add 2 tablespoons bottled lemon juice. Heat to boiling and boil for three to four minutes. Use one of the tests described above to determine if jelly is done. Remove from heat, quickly skim off foam and fill sterilized jars. Leave 1/4-inch headspace. Adjust new lids and process the jars as directed.
Mother Nature produces fruit, so sometimes, depending upon your fruit’s sweetness, jam just doesn’t set as much as we’d like it to. If this happens, just go with the flow and enjoy it over ice cream!