Little did I know that making a batch of jam was going to awaken my inner (largely dormant) nerd, but all this talk about jam-making and preserving has really piqued my interest. Without going into too much detail, here are the basics we need to determine before we set out: 1) fruit(s) used 2) amount of sugar.
Pectin is a naturally occurring substance that’s found in fruit, although more concentrated in some fruits than in others. For example, while grapes, plums, and apples have a high pectin content, strawberries, apricots, and peaches contain very low levels of it.
Seasonal fruits are best for jam-making, but you do need to determine whether they have enough of the gelling agent present in them (assuming you’re like me and don’t want to use any commercially bought pectin/setting agents). One way of getting past this low-high conundrum is to use a combination: if the fruit you want to use is on the low-pectin list, combine it with one that has a high pectin count. Using plums with strawberries is a classic example of this.
Most often than not, you will find recipes that dictate a 1:1 fruit to sugar ratio for jams and preserves. Don’t quote me on this, but I’m pretty sure that’s what commercial brands use. Since sugar acts both as a preservative and as a setting agent in the jam, what’s the best way to increase its shelf life? Dump more in. Not to mention that the texture of this sickly sweet product is akin to something you can bounce off of a wall (let’s not even go into the vile artificial colouring part).
What I was after was a soft-set jam, sweet enough to counter the lip-puckering tartness of the plums while still retaining its original flavour (this recipe is versatile, so you can add more sugar if you want). I also wanted it to look and taste as homemade as possible, so I kept the fruit quite chunky and left the skins on. The only drawback with using less sugar is that it won’t keep for as long – two months maximum, but I seriously doubt that that would be a concern.
- 800 grams plums, pitted and quartered
- 250 grams sugar
- Juice of ½ a lime/lemon
- Place a heavy-bottomed pot over medium heat and toss in the plums. Stir, then clamp on a lid and cook until tender and the plums are falling apart, about 5-10 minutes (the timing will depend largely upon the ripeness of the plums). Push the plums down using a spatula and mush them as you go along.
- Once the plums are tender, add the sugar to the pot. Cook the jam over medium-high heat stirring frequently until the sugar is dissolved. Continue simmering for a further 10 minutes, skimming off any scum that rises to the surface (note: stir frequently at this stage as there is a risk of the sugar catching at the bottom).
- Continue cooking until the jam has thickened, another 5 - 7 minutes or so. (A good way to tell if it’s done is to scoop some up in a ladle and pour it back into the pot. You want it to fall in clumps and not be too runny). If you think it’s not there yet, let it cook for a little while longer.
- Taste the jam; if you think it’s too tart, add more sugar and cook until it dissolves completely.
- When ready, add the lime/lemon juice and ladle them into clean glass jars. Let them sit outside until they get to room temperature and then refrigerate.
- I like to keep the fruit quite chunky. If you’d prefer it smooth, purée the plums after cooking them (before you add the sugar).
- The jam will thicken slightly as it sits in the refrigerator.
* Adapted from David Lebovitz