A Few Tips for Making and Canning Jam:
Of course, there's tons of information available online for expert jam makers. These are just the main points I feel are important to focus on and that have been really useful for me in my experience.
What's the difference between Jam, Jelly, Preserves and Marmalade?
Jam consists of crushed fruit, with or without seeds.
Jelly is made from fruit juice and sugar, and is very smooth and clear.
Preserves consist of whole chunks of fruit, in syrup or jam.
Marmalade consists of whole chunks of fruit and rind, usually citrus fruit. The rind adds a little bitterness to counteract the sweetness of the fruit.
Ratio of Fruit to Sugar:
The general rule of thumb is approximately equal weights of fruit to sugar (1 pound of fruit needs 1 pound of sugar.
This sounds like a lot, and it is. Jam is sweet. But sugar is also a natural preservative, so if you use less sugar, then your jam will have a shorter shelf-life.
What makes jam "jammy"?:
Pectin is a gelling agent that is naturally found in, and extracted from fruit, particularly citrus fruit. Some fruits contain more natural pectin than others. It's available in packets or bulk jars, and is a whitish sort of powder. The addition of pectin is what causes jelly to gel.
There are several varieties available, such as Low-Sugar and Classic. I have only used the Classic version.
If I were making a small batch of quick jam to eat right away, I wouldn't use pectin, I would just let the fruit simmer on the stove until reduced and thickened enough to spread over toast. But for large batches and/or canning, the pectin is needed.
Also contributing to the gelling of the jam is the addition of lemon juice, which is high in pectin.
Pectin jars also come with basic recipes for making jam, and you really can't go wrong following that formula.
Spices and Other Flavors:
Other than fruit, lemon, pectin and sugar, you don't need to add a lot to your jam, since the fruit is supposed to be the star, after all.
But a few complimentary spices can be really nice, and can add some interesting flavors.
Besides containing pectin, I like lemon added to jams simply because the bright, tart citrus notes are a nice contrast to the super-sweet fruit.
A few favorite spices to stir in are cinnamon, nutmeg and ginger. A touch of vanilla can be nice, too.
A very small amount of butter helps to remove any foam that collects on top of the jam while cooking.
Experiment with combining two different fruits - I've made Strawberry Apricot, Apricot Peach, Cranberry Blueberry, Black Cherry Vanilla, Red Currant Blackberry...
Water Bath - necessary or not?:
YES - If you're planning to store the jam in your pantry and/or give away as gifts. A hot water bath is the only approved, safe method for preserving jam and preventing bacterial contamination. Most recipes should have instructions for the recommended number of minutes of boiling in the water bath (high altitude takes longer).
NO - If you're planning to refrigerate and eat the jam within a few months.
Equipment Needed:
Canner - Probably not necessary if you're just canning a few jars here and there, and if so then your largest stock pot is fine. It needs to be big enough that the tops of the jars are covered with at least an inch of water. If you'll be canning large batches, then you'll probably want one of those great big canners that can hold a lot more. My biggest stock pot only holds 7 jars, so it takes a while to process in batches if I'm canning more than that.
Jar Funnel - Very nice to have. Otherwise, you splash jam everywhere while trying to ladle or pour jam into the jars.
Jar Lifter - A must have. I have tried those little plastic baskets (useless) and rubber-tipped tongs (dangerous) and finally gave in and spent the $9 to buy a jar lifter. Don't mess around when it comes to a huge pot of boiling water.
Glass Jars - Obviously. Use whatever you like, plain or quilted, 4-ounce, half-pint, 12-ounce or pint. Before filling with jam, they need to be clean, hot and sterilized (this is best accomplished by running them through the dishwasher with the heated dry on). If they are hot to begin with, this will lessen the chance of breakage when filled with boiling jam. Jam should be filled to about 1/4 inch from the top of the jar - this gap between the jam and the lid is called "headspace", and it allows for expansion during the water bath. Most recipes will include the recommended headspace for what is being canned. After filling them with jam, wipe the rims with a clean damp cloth, before putting the lids on. Glass jars can be used over and over.
Lids and Rings - If you are just filling jars to refrigerate, then you can reuse old lids and rings, unless they're rusty, and then that's just gross. But for canning where you don't want any bacterial contamination, you must use new lids and rings every time. Once they are used, they may no longer seal properly. After filling the jars, place the lids on top of the jars. Tighten the ring "fingertip tight", meaning, you're not wrenching it as tight as you can, just lightly tightening it; this allows steam to penetrate under the rings to seal the lids properly. You will know it is sealed if the center of the lid is indented (this may not happen until a few hours after the jar has cooled). If it is popped up, it didn't seal, and will need to be refrigerated and consumed. The ring may even be loose when you take the jar out of the water bath - this is normal and nothing to worry about - they don't even need to be tightened if the lid has sealed.
Getting Started:
Be sure your jars, lids and rings are clean, sterilized and hot (just run them in the dishwasher beforehand) before you get started.
I would like to be able to tell you the weight of the fruit, but the truth is, the battery in my kitchen scale died, so I was unable to weigh the fruit, and only able to provide the volume once I had it all cut up. I did have 5 peaches, which yielded 2 cups when chopped. And a huge pile of apricots - they were very small, so there might have been 50 or so in the pile, but I didn't count them...
The easiest way to peel the fruit is to blanch them. Bring a large pot of water to a boil. You will also need to have a large bowl on the counter filled with ice water, and a baking sheet covered with a towel. Carefully drop the fruit, a few at a time, into the boiling water. Leave for 40 seconds; if the fruit isn't quite ripe yet, leave for a full minute. Using a slotted spoon, remove from the boiling water and transfer directly to the ice water bath. Leave for about 30 seconds, then transfer to the paper towel to drain. Repeat with the remaining fruit. After blanching them, the skins will slide off very easily.
All those little apricots will take a while to peel, then remove the pits and cut them up, but be patient. The result is well worth it.
Once all the fruit is ready, measure out the rest of the ingredients and have them ready to go.
This recipe can easily be pared down to a smaller quantity (it makes 9 half-pint jars / 9 cups of jam); the reason I made so much is because I had so many apricots I had brought home from a weekend trip, and needed to use them up.
Apricot Peach Preserves (with a hint of ginger and nutmeg)
5 cups peeled and chopped apricots
2 cups peeled and chopped peaches
juice and zest of 2 lemons
2 tablespoons diced candied ginger
1/4 teaspoon ground ginger
1/2 teaspoon ground nutmeg
5 tablespoons classic pectin
4 1/2 cups granulated sugar
1 tablespoon unsalted butter
1 teaspoon vanilla
Making the Jam:
In a large stock pot, combine the fruit, lemon zest and juice, candied ginger, ground ginger and nutmeg. Bring to a simmer over medium low heat.
Gradually stir in the pectin. Increase heat to high (be sure you are wearing oven mitts to protect your hands and arms from boiling jam splatters) and stir constantly to bring to a rapid boil.
Dump all the sugar in at once. Continue stirring constantly to return to a vigorous boil that can't be stirred down. Boil hard for one minute.
Remove from the heat. Stir in the butter (to reduce any foaminess) and the vanilla.
Ladle into your hot, sterilized jars, leaving 1/4 inch "headspace" at the top, to allow for expansion.
Wipe the rips with a clean, damp cloth, center the lids on the jars, and screw on the rings "fingertip tight".
Process in a water bath according to standard canning procedures (about 10 minutes in boiling water at sea level and 20 minutes in boiling water for high altitude).
Carefully remove from the water bath (using a jar lifter) and set on the counter to cool overnight. The next day, check the lids - if they are indented, then the jars sealed properly and you can store the jam in your pantry until ready to use. If the centers of the lids are popped up, then they didn't seal properly, and will need to be stored in your refrigerator and eaten in the next 3 months or so.
Yields 9 half-pint jars.
Recipe from Curly Girl Kitchen