“The rule is, jam to-morrow and jam yesterday—but never jam to-day.”

– Lewis Carroll, Through the Looking Glass.

My homemade English muffins seemed to cry out for some rich red raspberry jam so I went for it – my first stab at canning. I didn’t have much to go on but I thought, This is jam – how hard can it be, right? Just mix equal parts sugar and fruit, with some lemon juice thrown in, and boil away.

Ah, not so fast, grasshopper. Remember poor Meg March and the jelly scene in Little Women? Successful jam is all about the art of the “set”, as well as the tricks of the (homemade jam) trade.

The Questions

• Are all those canning wazoos and gadgets truly necessary, when you’re already trying to justify the new pastry brushes you just bought?

• Should you warm your sugar first?
• Do you add lemon juice or leave it out?
  • Sub lemon juice questions – how much? bottled or fresh?
• Should you add commercial pectin?

I tell you, delve into just about any subject and you realize how many rabbit holes there are.

The Answers

• Given that there’s only two of us in my humble abode, I went with small batches of jam. Which meant no long-term storage, hence no new “equipment” necessary.
• As far as warming the sugar first – which is supposed to reduce jam boiling time, which is supposed to result in tastier, fresher jam – it was a pretty messy operation. Sugar is like sand in that it gets everywhere. I’m still trying to determine if it’s worth it.
• Yes to the lemon juice for many fruits, though how much you add should really depend on how much pectin and acid the fruit contains in the first place. Not only does the lemon help with the pectin “gelling” process for most fruit jams, but it also improves shelf life and helps prevent spoilage. (The case for bottled lemon juice is because it’s controlled and standardized but I’m okay with using fresh.)
• And finally, a brief guide to fruits and their pectin concentrations is below.

A Brief Pectin Primer

Pectin is a long chain of carbohydrates – in this case, a polysaccharide – and is found in the cell walls of plants, providing structure for the flowers and leaves and stems, as well as holding the cell walls together. It’s most concentrated in the skins, pips, and cores of raw fruit, with some fruits, e.g. apples, having high levels and some, e.g. strawberries, having low levels. In a solution, and with the assistance of sugar, acid and heat, pectin forms a network that traps liquid and sets as it cools, which in the case of jam, means delicious bits of fruit get trapped in that network too.

General Tips

• For low-pectin fruits (see below), you can add another fruit with high pectin to help compensate. You can also add commercial pectin – don’t worry, I won’t judge.
• For naturally-acidic or tart fruits, you might want to lessen the amount of lemon juice.
• For full-flavored jam that sets well, a mix of slightly under-ripe fruit (more pectin) and just-ripe fruit (more flavor) is probably the way to go.
• Use a wide pot to boil the fruit and sugar.

High-pectin fruits

Cooking apples, blackberries (sour), loganberries, crabapples, cranberries, quinces, lemons, limes, currants, and many plums.

Medium-pectin fruits

Ripe apples, grapes (California), raspberries,* loganberries, blackberries (ripe), sour cherries, grapefruits, oranges.

Low-pectin fruits

Apricots, blueberries, sweet cherries, strawberries, Italian plums, rhubarb, figs, peaches, nectarines, pears, guavas, pomegranates.

*raspberries are sometimes listed as being low-pectin but behaving as other medium- or high-pectin fruits when it comes to jam-setting

Reality Bakes

Even after all that research, my jam didn’t really set. Next time, I’ll try the cold-plate test instead of the spoon test, which I apparently did not perform successfully. I’ll also use a bigger pan, mix in some less-ripe fruit, and skim the jam before canning.

Raspberry Jam Playlist