A quick recipe for one bottle of marmelade, I use it to avoid canning - just put it in any bottle and refrigerate after making. It's best when it's first made though, and still warm. I like my marmelade tart - if you find it's too sour for your tastes, just use more sugar. Note: you don't need any gelatin, there's plenty of natural gelatin in the peel of all citrus fruits.