Knowra Jam Jam Jam is a thick fruit preserve made by cooking fruit or fruit pieces with sugar. Its texture comes from concentrated fruit solids and, in many recipes, pectin.
Pectin : A group of plant polysaccharides that form gels in suitable conditions, especially with sugar and acid. Pectin helps cooked fruit set into a spread rather than remain a syrup.
Fruit : The seed-bearing structure of flowering plants, often containing seeds and surrounding edible tissue. Fruit supplies jam’s flavor, color, acidity, and much of its texture.
Canning : Food preservation by heating food in sealed containers to destroy spoilage organisms and prevent recontamination. Sealed jars allow properly processed jam to be stored without refrigeration.
Jelly : A clear fruit preserve made from fruit juice, sugar, and often pectin, set into a firm gel. Unlike jam, jelly is made from strained juice rather than pieces of fruit.
Gelation : The formation of a gel, a soft solid network that traps liquid. Jam thickens when dissolved pectin forms a network that holds fruit liquid.
Citric acid : A weak organic acid found naturally in citrus fruits and widely used in food. Acidity supports pectin gel formation and balances the sweetness of cooked fruit.
Water bath canning : A canning method that processes high-acid foods in jars submerged in boiling water. Many jam recipes use this method because fruit preserves are acidic.
Marmalade : A citrus preserve made with juice and peel, typically cooked with sugar to form a gel. Marmalade is distinguished by citrus peel, while jam commonly contains fruit pulp or pieces.
Fruit pectin : Pectin occurring naturally in fruit, with amounts and gelling ability varying by fruit and ripeness. Its natural abundance helps explain why some fruits set more readily than others.
Water activity : A measure of water available in a material to support chemical reactions and microbial growth. Sugar lowers available water, one reason properly prepared jam resists spoilage.
Show all 21