HOME canning once struck me as remote and quaint -- far too time-consuming to contemplate actually doing, and with the element of risk that the jars would be inadequately sterilized and I'd poison both myself and the recipients of my lovingly homemade gifts. Besides, if I wanted to store something particularly ripe and seasonal, I had the unquaint freezer. Late one summer I found myself alone at a friend's California house with exceptional tomatoes going to waste in the garden, an unopened box of canning jars in the pantry, and a deadline waiting in the study. The whole enterprise took on sudden allure. It turned out to be remarkably, even disappointingly, easy.
The question before anyone thinking of "putting food by," as the title of an authoritative manual has it, remains this: Wouldn't it be easier -- and just as satisfactory -- to go to the store? If the food in question is something you've grown yourself, objectivity is impossible. If, however, the food is bought, considerations of time and shelf space come into play.
In many experiments with marmalade over two winters, I decided that for citrus it's worth it. The flavor is brighter, sharper, and more distinct than it is in marmalade you can buy. (Terminology is loose, but the general distinction is that jellies are made from juice alone, jams include crushed fruit, and marmalades include citrus rind. Preserves are whole fruit or chunks of fruit in syrup, and conserves include nuts, spices, and other oddments.) You can actually tell what fruit you're eating -- not always possible with marmalades from even the most homestyle-seeming producers -- and even though you're using pounds of sugar at a time, the taste of the finished marmalade will be much less cloying.
Also, lemon marmalade is scarce. Indeed, I never tasted lemon marmalade until I made it. After one spoonful I realized that whatever the dictates of tradition, oranges were expendable. (The name "marmalade" didn't originally refer to citrus anyway; it derives instead from a word for quince, another tart fruit that home cooks boil with sugar.) My revelation came in another house, as I avoided another deadline, with a lemon tree outside the kitchen window; it was confirmed at home, where I used the wonderfully sweet Meyer lemons, thanks to Diamond Organics, which ships them year-round (the number is 800-922-2396). Meyer lemons, which grow in many California back yards, are thin-skinned and almost seedless, with a clean, only lightly acidic flavor. Their two peak seasons are the early fall -- and now.
I was lucky in my choice of gardens: tomatoes and citrus provide easy and safe introductions to home canning, because both are high in acid, which naturally retards the growth of most micro-organisms. (Pickling is the commonest way to home-can vegetables, not because so many cooks love vinegar but because it renders low-acid vegetables safe.) Sugar, too, retards bacteria, because it chemically binds with water and ties up a natural medium for growth; it's safe to eat most jellies (and honey) long after it might be wise to throw out other bottled foods. In sweet home-canned goods the goal is to make something that jells, lest you bottle syrup. This can be a very tricky matter for many fruits. Acid, sugar, and pectin determine the "setting" point, and luckily marmalade is high in all three. Commercial pectin is usually made, in fact, from the pith (the white part of the rind) of citrus fruits.
Most marmalades, then, will jell readily and pose little danger of spoilage -- if you use the classic proportion of one part sugar to one part fruit. Low-sugar preserves require the addition of commercial pectin, which makes for complications, and low-sugar marmalade is also subject to fermentation. After experimenting with reducing the proportion of sugar for fruits that seemed sweet and raising it for particularly sour ones, I came to the convenient (and to me surprising) conclusion that one to one always produces the clearest and best flavor.
This ratio is by weight: in home canning, as in serious baking, a kitchen scale is essential. So is a thermometer, to remove anxiety from the decision of when the marmalade is done. Either a jelly or a deep-fat-frying thermometer will serve; most hardware stores sell them for a few dollars. You don't need a special preserving kettle, attractive as the tinned copper ones are, with their slightly flaring sides and curved, swinging handles. Any heavy-bottomed pan wider than it is deep, so as to encourage fast evaporation, will do. Canning jars with screw-top metal lids -- easier to manage, if less appealing, than jars with clamping glass lids -- are available at most supermarkets and hardware stores.
Small batches are always more manageable: the preparation is easier, and so is bringing the marmalade to the setting point. As the writer Jeanne Lesem points out in her concise and informative , most of us do "not need or want...dozens of jars of anything." Still, there's no better gift than a jar of your own marmalade. Don't lose the decorative labels that come in most boxes of jars -- they're necessary for pride of authorship.
THE British are the world's masters of marmalade, and they have evolved many ways to make it. Guided by the no-nonsense voice of May Byron, whose Jams and Jellies was published in England in 1917 (Dover reprinted it in 1975), I tried them all, and boiled the techniques down (sorry) to three: what I call whole-fruit, cut-rind, and shredded-zest.