Easy Plum Jam – Small Batch

My delicious home-made plum jam is perfect spread on toast, crumpets or tea cakes. This quick and simple small-batch recipe produces a couple of delicious pots and needs no added pectin. 

Easy Plum Jam

This plum jam recipe will convert you to jam making. It’s very simple to make, and I find that it takes only a few minutes at the stove, thanks to my favourite small batch method.

Fresh ripe plums are one of the great British soft fruits. They have a short season, so I enjoy them while I can and capture that flavour for the rest of the year by making jam.

Jam will keep safely for several years but it does lose its freshness and flavour over time. I don’t know about you, but the back of my cupboard used to hold far too many jars of ancient too-solid jams. So now I avoid this by making small batches, and enjoying the jam at its best. If I run out before the next season, I’ll enjoy something else instead.

We have used a red plum with a golden flesh for the jam, you can, of course use any type of plum.  

Don’t I Need Pectin?

No. This plum jam recipe doesn’t use added pectin. The natural pectin in the fruit and the lemon juice sets it very well.

Jam or Conserve: What’s the Difference ?

When making jam, the fruit is sliced and then cooked before the sugar is added. This is necessary for fruit that need more cooking time.

For a conserve, whole raw fruit is left to stand in sugar to draw out the juice. The resulting mixture is then heated to a setting point. By doing this, you minimize the cooking time and keep the fresh flavours of the fruit. You also keep the shape of the fruit pieces. This plum jam recipe uses the conserve method. 

My Easy Plum Jam Recipe

Step one – Cut the plums in half, remove the stones and cut off any bruises.  Cut each half into about 8 pieces. 

Step Two –  Put half the chopped plums into a bowl and pour half the sugar over.  

If you have a glut of plums to use, but no time to make jam, you can freeze them at this point. Just make a note of the weight of plums and sugar used.  

Repeat and make a second layer. 

Cover the bowl and wait.  The sugar will start draw out the juice.  

Leave overnight.  The sugar will draw out the plum juice and make a thick syrup.  There will still be some solid sugar in the bowl.  

Step Three – Sterilize clean jam jars and lids by placing them on a baking tray in the oven at 120°C/250°F/GM1.

Step Four – Transfer the plum and sugar mixture to a large saucepan or preserving pan, and simmer gently until all the sugar is dissolved. Add the lemon juice.

Step Five – Once the sugar has dissolved, heat the mixture quickly to a rolling boil. Then start testing to see if will set. (See below for more information on this.)

Finally, let the plum jam cool for about ten minutes before you spoon it into the jars – this allows it to cool and thicken and will help stop all the pieces of fruit rising to the top, you want your fruit evenly distributed throughout the jam. 

I ladle my jam into a toughened glass jug and pour into the jars through a jam funnel, which helps to stops any stray drips of jam.

Seal the lids while the jam is still hot. As it cools, you’ll hear the lids pop as the vacuum forms. It’s always a satisfying noise after a day with the preserving pan. Clean up any drips, stick on a label and you’re all done – delicious, easy plum jam.

Checking the Set

• First is by temperature; carefully check the jam with an accurate electronic thermometer. The liquid should reach 105°C/221°F. Once the jam has reached this temperature, you know that it should be ready.  However use temperature as a guide, thermometers are inaccurate and a pan of boiling preserve will have some hot spots.  Always check using one of the other methods below. 
• Second, the traditional test using a chilled plate. Before you start cooking, put a side plate in the freezer to chill. Once the jam is boiling, start testing by placing some jam on the plate and let it cool. When you push your finger through, look for a wrinkle ahead of your finger. Once you can see this, the plum jam is ready. This technique takes a bit of practice.
• Third, you can test for setting by checking the way that the jam runs off a spoon. Take a spoonful from the pan and turn it vertically so that the jam falls. If it all runs off, it won’t set. If, however, a little remains on the spoon in a sort of wide drip that doesn’t fall, then the jam is ready.
  Again, this works best with some practice. The advantage of small batch jam is that by making little and often, you tune your senses as to when the jam is done and will be able to see when it is ready by its appearance when it is boiling.
• For more detailed notes on jam setting points, see my blackberry and apply jelly recipe.

With time you will be able to gauge setting point from the appearance, and sound, of the simmering jam.  

If you are in doubt pot the jam – it is easier to remedy a soft set jam than an overset one.

How to check your jars have sealed 

It is crucial to check your jars have sealed – you would have heard the little pops as the lid of each one was sucked in as it cooled. 

Leave the jars out for 24 hours, and press the centre of each one. The centre of the lid should stay put it, showing that it is sealed, and the jar can by put away.   

If the centre of the lid pops up when released, it hasn’t sealed properly. If you have several unsealed jars you can open them all and re boil the jam, or if just one put it in the fridge and eat it immediately.  

Easy Plum Jam – ingredient ratios

Making jams by ratio makes the recipes easy to scale up and down.

• Use the same weight of sugar as fruit.
• Use  1–2  tbsp lemon juice per 500 g of fruit. Riper fruit needs more lemon, firmer fruit needs less. 
• 250 g of fruit makes about 600 g of jam.

Easy Small Batch Plum Jam – Hints Tips and Variations 

One of the reasons we love small batch preserving is that you can experiment with the recipe.

• Try a different type of plum, they all have slightly different flavours and come in a glorious spectrum of colours.
• Add some spices to mix up the flavour.  Cinnamon, cardamon or ginger would all be delicious.

Troubleshooting 

• If your set is too soft, then depending on how much jam there is to fix, you can either boil the jam up again, and re-pot, or leave for a good few months as it will thicken in the jar. 
• If the set is too solid, but the flavour is good, you can try adding some water and re-cook, but it is easy to caramelise the sugar.    
  • Add a little water, heat up and serve on ice cream or pancakes
  • Melt the jam, whisk with vinegar and BBQ sauce for a fruity BBQ glaze or marinade. 
  • Beat it into buttercream for a fruit flavoured frosting. 
• If the jam has started to caramelise, you usually can’t rescue it and I’d throw it away. 
• My jam has gone mouldy?  This can happen for a number of reasons.  The jar didn’t seal properly.   You didn’t sterilise the jars, or you used bruised or damaged fruit.  Throw the jam away – the mould goes far beneath the surface. 

How long does plum jam last?

If you have made the jam properly with quality fruit, and the lid has sealed properly, your jam should last for years stored in a cool dark cupboard. It will thicken and darken over time. 

Once opened I store jam in the fridge, this is largely due to a lack of cupboard space, and that we have several pots of jam and jelly on the go at once.  Homemade jam will be fine in a cupboard for 4 weeks after opening.

This is delicious served on a slice of freshly baked no yeast bread or spread on a slice of fruit loaf, with homemade butter.

More jam recipes

If you enjoyed this plum jam recipe, why not try more small-batch preserving?

• Nectarine jam
• Blackberry jam
• Quince jelly
• Blueberry jam
• other jam recipes

More plum recipes 

• Plum chutney
• Plums in port 
• Plum cake

It is also delicious in any fruity dessert, served with a glass of sloe gin!