Simple Plum Jam

This simple, fresh Plum Jam recipe is made with only 3 ingredients in under 20 minutes. This jam will become a family favourite with a sweet, fruity flavour and can top your favourite breakfast toast.

Jam making reminds me of my French Grandmother, who would make jars and jars of jam in various exciting flavours. Plum jam has to be one of my favourite jams, alongside blackberry jam, to slather on hot buttered sourdough toast or classic scones.

This recipe needs just 4 ingredients and a handful of simple steps to make this incredible jam. It's delicate in flavour and has the perfect texture.

Today, I'll share two easy ways to sterilise your jars, images and steps on how to make this plum jam but as my top tips on how to tell if the jam is set. You'll be a jam-making expert in next to no time!

🧾 Ingredients Needed

As you can see from the image below- the list is short, but I've made a few pointers on each ingredient below.

• Plums -Use any of your favourite varieties of plums. There are many colours, and your jam will take on the colour of the plums. I used the popular yellow fleshed plums with purple skin, and the jam took on the colour of the skin. So beautiful. Just make sure that you choose ripe, but not overly soft, mushy plums and cut out any blemishes.
• Sugar - Caster or granulated sugar is used. When you see the sugar in the bowl, it may look like a lot, but you need it all to allow the jam to set. Reducing the sugar will only hinder your efforts!
• Lemon Juice - Fresh lemon juice not only adds flavour, but the natural pectins found in the juice helps the jam to set. Occasionally, I add in the lemon zest which adds a lovely refreshing citrus note to the jam.
• Water - Just a small amount of water is added in at the start of the cooking process to help the stone fruit to soft and the juices to extract.

📖 Variations

• Cardamom Plum Jam: You'll need to crush 10 cardamom pods to expose the seeds, wrap the seeds and pods in a small muslin cloth square and add to the mixture right at the start of the jam-making process. Remove just before ladling jam into the jars.
• Plum Thyme and Lemon Jam: Add a sprig of thyme and the zest of 1 lemon to the jam as it cooks. The herbal citrus flavours will infuse into the jam and add fresh notes.
• Spiced Plum Jam: Make the perfect jam for Fall by including star anise, a cinnamon stick and a knob of peeled fresh ginger whilst the jam cooks. Remove when ladling into jars. The spices make the jam sing on your palette and add the perfect warmth.

👩🏻‍🍳 How to Make

*Be sure to see the recipe card below for the full ingredients list & instructions!*

In this section, I'm sharing how to turn fresh blackberries into a beautiful jar of sweet blackberry jam. Before making the jam, we'll tackle my two favourite ways to sterilise your jam jars. It's super important if you want to store your jam and not use it right away. 

First, place two small saucers in the freezer (tip- this helps see if your jam has set! I'll explain further!)

How to Sterilise Your Jam Jars

There are numerous ways to sterilise jars but I'm going to show you my two favourite ways

In the oven:

• Heat the oven to 14OC/280F.
• Give the jam jar, lids and any utensils you may be using, like a ladle, a wash in hot, soapy water and rinse off with clean water. Just so you know, if the jar has a rubber ring seal, please remove that and wash it also.
• Place the wet jars on a baking tray and into the oven - remove once the jar is fully dry- this can take about 10 minutes.

In a saucepan:

• Give the jam jars, lids and any utensils you may be using, like a ladle, a wash in hot, soapy water and rinse off with clean water. Note, if the jar has a rubber ring seal, then make sure to remove that and wash it also.
• Place the jar in a saucepan and cover completely with boiling water and boil for 10 minutes. Remove carefully from the water and allow to air dry.

Prepare the Plums

STEP 1. Slice the plums. Slices the plums in half, then de-stone. If the plums are small then slice them into quarters or if they are large then slice them into smaller pieces (Image 1).

Make the Jam

STEP 2. Soften plums. Add the plums and water into a large saucepan and heat on medium-low until the flesh of the plums has softened (Image 2). This will take 5 minutes or so, or a little longer if the plums are under-ripe.

STEP 3. Add the sugar and lemon juice. Add the sugar and lemon juice and allow the jam to simmer until the sugar fully dissolves (Image 3).

STEP 4. Allow the jam to boil. Bring the jam to a rolling boil on medium heat and cook until the mixture thickens (Images 4). If there is scum on the surface of the jam, then skim it off the top with a spoon. (TIP: You can also add a knob of butter into the jam, dispersing the scum without removing it!)

STEP 5: Check if jam has set. Alrighty, this is a crazy easy way to test if the jam has cooked for long enough. Remove one of the saucers from the freezer and drop a teaspoon of jam onto it (Image 5). With your finger, make a pass through the jam.

If the two sides of the pass don't move and join back together, and if the jam wrinkles, your jam is ready, yay!! 

If it does join, continue cooking the jam for a couple more minutes and test again on the other saucer from the freezer.

Alternatively, you can use a thermometer. The jam setting point is 104C/220F - when you reach this temperature, the jam is ready.

Store the Plum Jam

STEP 6: Fill your jar! Ladle the jam directly into your sterilised jar/jars (Image 6). Leave 2 cm room from the top. Tap the jar or use a knife, stirring out any air bubbles. Wipe the rim of the jar clean and screw the lid on tight. The jam will thicken as it cools.

Allow to cool fully before storing in the fridge. 

🥣 How To Serve

There are so many ways that you can use this incredible jam. 

• On toast, crumpets, English muffins, croissants, or pancakes.
• Spread over your favourite crêpes or french toast.
• Use as a filling in sponge cakes or cupcakes.
• Dolloped ontop a bowl of breakfast yogurt or porridge.