The fruit known for its high pectin content and often used to make jellies is the apple. Apples, particularly certain varieties like the Granny Smith and McIntosh, contain a significant amount of pectin, a natural polysaccharide that acts as a gelling agent. When apples are cooked and combined with sugar, pectin helps create a thick consistency essential for jams and jellies. This property makes apples a popular choice for home canners and commercial jelly producers. Other fruits high in pectin include citrus fruits and quinces, but apples are the most common in jelly-making traditions worldwide, appreciated for their flavor and gelling ability.