Traditional jam and jelly are made with pectin that requires acid and sugar to create a gel. The sugar also acts as a preservative to prevent mould growth.
To create jam with a low-sugar content, natural citrus pectin is modified so the pectin bonds with calcium to form a gel. To assure that there is sufficient calcium available to create a gel, it is added to the fruit mixture.
The modified pectins are called low-methoxyl pectins (LMP). This type of pectin does not readily dissolve in liquid so the dry pectin is mixed with a small amount of sugar or other sweetener before it is added to the crushed fruit or juice.
The mixture is then boiled and stirred to ensure the pectin is dissolved. Additional sweetener can be added after the pectin is dissolved if desired.
Dicalcium phosphate salt, a calcium salt needed to make the gel, is usually sold with LMP for this purpose.
The salt is mixed with water at the rate of 1/4 teaspoon (1 mL) dicalcium phosphate per 1/4 cup (60 mL) water. The amount of calcium solution needed will vary with the degree of hard water. The salt does not dissolve readily in water, so the calcium solution must be mixed thoroughly and measured while the liquid is cloudy.
Jam and jelly can be sweetened with small amounts of sweetener such as sugar, honey, agave, maple syrup, frozen juice concentrate and concentrated fruit or artificial sweeteners.
Agave can be used just like honey but it doesn’t impart any taste. It is possible to make preserves without sweetener but it is not recommended because the final product is likely to be tart and bland.
These spreads are low in sugar so to prevent spoilage, they need to be processed in a boiling water bath and sealed for shelf storage or stored in the freezer for up to one year. Cooked and processed low or no sugar jam, once opened, will last about three weeks in the refrigerator.
If the recipe directions are followed, the jam should gel when it is completely cool 12 to 24 hours after removing it from the water bath.
If the gel is too stiff, too much calcium was added and the water was probably too hard. Reheat and add more juice.
If the gel is too thin, not enough calcium was added, so try reheating and adding more calcium solution.
Unlike other pectins, it is possible to develop your own recipes or convert a recipe written for a different pectin to a LMP recipe. The LMP can be stored indefinitely if stored in a tightly sealed container.
Acid, such as lemon juice, is not needed to promote gel formation but can be added to the jam or jelly to enhance the flavour and colour.
Blueberry nectarine no sugar jam
Prepare calcium water by combining 1/2 teaspoon calcium powder (small packet in box of Pomona’s pectin) with 1/2 cup water in a small, clear jar with a lid. Shake well. Extra calcium water may be stored in the refrigerator for future use
- 3 c. fully ripe mashed nectarines 750 mL
- 1 c. blueberries 250 mL
- 1/4 c. lemon juice 60 mL
- 1/4 c. calcium water (shake the jar well before measuring) 60 mL
- 1/2 c. honey 125 mL
- 3 tsp. Pomona’s pectin powder 45 mL
Wash your jars, lids and bands. Place jars in canner, fill canner 2/3 full with water, bring canner to a rolling boil and boil jars for 10 minutes to sterilize them. Reduce heat and allow jars to remain in hot canner water until ready to use. Place lids in water in a small saucepan, heat to a low simmer, and hold until ready to use.
Peel and remove pits from nectarines, then mash in a large bowl.
Measure three cups (750 mL) mashed nectarines and one cup (250 mL) blueberries, pour into a saucepan along with lemon juice and calcium water. Mix well.
Bring fruit to a full boil over high heat. Slowly add pectin–honey mixture, stirring constantly. Continue to stir vigorously for about two minutes to dissolve pectin while the jam comes back up to a boil. Once the jam returns to a full boil, remove it from the heat.
Remove jars from canner and ladle jam into hot jars, leaving 1/4 inch (0.5 cm) of head space. Remove trapped air bubbles, wipe rims with a damp cloth, put on lids and screw bands and tighten to fingertip tight. Lower filled jars into canner, ensuring jars do not touch each other and are covered with at least one to two inches (2-4 cm) of water.
Place lid on canner, return water to a rolling boil and process for 10 minutes. (Add 2 1/2 extra minutes of processing time for every 1,000 feet above sea level.)
Turn off heat and allow canner to sit untouched for five minutes, then remove jars and allow to cool undisturbed for 12 to 24 hours.
Confirm that jars have sealed, then store properly. – Source: www.pomonapectin.com.
- Preserving with Pomona’s Pectin: The Revolutionary Low-Sugar, High-Flavor Method for Crafting and Canning Jams, Jellies, Conserves and More by Allison Carroll Duffy and Pomona’s Partners. Check out the website, pomonapectin.com, for a how-to video.
Betty Ann Deobald is a home economist from Rosetown, Sask., and a member of Team Resources. Contact: email@example.com.