All fruits are suitable for preserves, especially if they come in vibrant colors, but some, like apples, quinces, pears, plums and grapes, are naturally high in pectin and will gel beautifully without additives.

Jellies must be firm and transparent like colored glass, in brilliant jewel tones, with no cloudiness or leftover bits of fruit.

Quince jelly, a delicacy of the northern countries (quince trees don't thrive in warm climates), is the gold standard for this sugary confection.

It achieves perfection on all fronts: the high pectin content gives it superior consistency, its flavor and fragrance are out of this world, it is sour enough so its sweetness does not overwhelm, it runs clear when strained and its color is a radiant rose amber, which looks like it glows from within.

Quinces are an acquired taste, I'll grant you that, but once you acquired it, you never lose it. These late fruits of the fall are tart and sour, so much so some won't consider eating them raw, but cooking them releases such fragrance and flavor they can define autumn all by themselves. You can keep them in a sunny window where they release their unforgettable fragrance all winter long.

Don't forget to add sugar. They're really sour.

Author's Bio: 

Main Areas: Garden Writing; Sustainable Gardening; Homegrown Harvest
Published Books: “Terra Two”; “Generations”; "The Plant - A Steampunk Story"; "Letters to Lelia"; "Fair"; "Door Number Eight"; "A Year and A Day"; "Möbius' Code"; "Between Mirrors"; "The Blue Rose Manuscript"
Career Focus: Author; Consummate Gardener;
Affiliation: All Year Garden; The Weekly Gardener; Francis Rosenfeld's Blog

I started blogging in 2010, to share the joy of growing all things green and the beauty of the garden through the seasons. Two garden blogs were born: allyeargarden.com and theweeklygardener.com, a periodical that followed it one year later. I wanted to assemble an informal compendium of the things I learned from my grandfather, wonderful books, educational websites, and my own experience, in the hope that other people might use it in their own gardening practice.