Blackberry Jam

Blackberries are a delicious fruit that is naturally high in pectin. This makes it a great fruit to make an easy blackberry jam which needs no added pectin. With blackberries, sugar, and a splash of lemon juice, you can easily have some delicious, no pectin, low sugar blackberry jam ready to enjoy on toast, pancakes, waffles and more.

 

Blackberries

To make this simple blackberry jam, you will need blackberries. If you are picking your own berries, make sure to pick them from an area that hasn’t had any nasties sprayed on them. It is also a good idea to clean them thoroughly. Soaking them in salted water will help clean them and remove any bugs. Dry thoroughly before using.

When choosing the blackberries for your jam, it is best to use ripe and slightly underripe berries as overripe ones tend to have less pectin in them.

Getting Jam to Set

For jams to thicken and set, they need a substance known as pectin. Some fruits naturally contain more pectin than others. When making jams and jellies with low-pectin fruits, often lemon juice is added.

High-pectin Fruits

• Apples
• Blackcurrants
• Redcurrants
• Gooseberries
• Raspberries
• Plums
• Cranberries
• Oranges
• Lemons
• Apricots
• Blackberries
• Blueberries

Low-pectin fruits

• Strawberries
• Rhubarb
• Peaches
• Cherries
• Pears

If you are using low-pectin fruits in your jam, you should also add some lemon juice or perhaps mix in some high-pectin fruit to help your jam to set. Alternatively, using jam sugar with low-pectin fruit works well.

To make jam, you need to soften the fruit first. We like our strawberry jam relatively smooth, so while softening the fruit, I used a masher to mash it to a smooth puree, though this is just our personal taste. 

The mixture will then need to boil and thicken and you will need to stir it frequently so that it doesn’t burn or stick to the bottom of the pot. If you have a candy thermometer, it needs to read 105°C (220°F), though you will need to keep a close eye on the mixture when it starts getting around this temperature.

If you don’t have a thermometer, you can use the jam / cold plate test. Before starting your jam, simply place 3 or 4 small plates in the freezer. When you think the jam may be ready, place a small teaspoon amount of jam onto one of the cold plates from the freezer and let it sit for about 30 seconds. Then run your finger through the middle of the blob of jam. If the line starts to fill back over, it means the jam is too runny and is not ready yet, so keep cooking and repeat again in about five minutes. If the line remains, then the jam has reached setting point and is ready.

This jam needs to be placed into sterilised jars. This recipe makes about 3-4 cups of strawberry jam, so you won’t need too many jars. It will need to be stored in the fridge and should last about 1-3 months this way. Though, if you follow the correct instructions for canning (the hot water bath method), you will be able to store it in the pantry for up to two years.

Can I Freeze Blackberry Jam?

Yes! You can freeze it right in the jar. Just make certain that you have preserved it properly and definitely leave some space at the top as it will expand a tiny bit when freezing.

Why Didn’t my Jam Set?

There are many reasons as to why your jam didn’t set. It may have needed to be cooked longer or sometimes, the fruit you used didn’t have enough natural sugar and needed a little more pectin added.

If you followed these instructions and your jam didn’t set properly, place your jam in the fridge overnight. If it isn’t set in the morning, you could try re-cooking it a bit longer and may be adding a bit of pectin or some more sugar and lemon, though make sure to taste test as you don’t want to add too much that it may affect the flavour.

Sterilisation

There are a few ways to sterilise your jars.

Was the jars and lids in hot, soapy water. Rinse the jars I hot water and place upside down on racks in an oven heated to 120˚C. You can line the racks with baking paper first, if you want. 

Heat the jars for 20 minutes. 

You can also clean and sterilise your jars by washing them in hot, soapy water then rinsing them well.  Then, boil them in a pot of water for about 15 minutes. (Make sure the jars are completely dry before filling them.)

Do not place cold jam into hot jars or hot jam into cold jars as they may crack and break.

Making Blackberry Jam

To make blackberry jam, you will need:

• 1 pound (454 grams) Blackberries
• 1 ½ cups White Sugar
• 2 TBSP Lemon Juice, freshly squeezed

Place two small saucers or plates in the freezer. You will use these to test when the jam is set if you don’t have a candy thermometer. 

Prepare the blackberries by washing, and drying. You can cut them in half if you wish as well.

Place the blackberries, sugar and freshly squeezed lemon juice into a large saucepan.

Heat over medium low heat, stirring regularly.

Once the sugar has completely dissolved, mash the blackberries into smaller bits, if you wish. 

You can then run the smashed berries through a mesh sieve, catching the syrup and pulp, discarding the seeds and core. Again, this is optional.

Boil for around 20 minutes, while stirring regularly until the jam reaches the gel stage. Check by dropping a little of the jam onto a chilled saucer. This jam can take up to 30 minutes to reach the gel stage. Note that during this time, the blackberry jam can heavily foam. You will need to watch it continuously and stir as the foam rises.

To help with the foaming, a small dab of butter can be added to the mixture. Though this is not necessary if you stir when it foams up.

Let the dropped jam stand for 30 seconds and then run your finger through it. If it wrinkles, the jam is ready. If it is still quite runny, cook the jam for a further 1 to 2 minutes before retesting.

When the jam is done, carefully ladle into prepared canning jars leaving ¼ inch headspace. 

Store in the fridge for up to 3 months, or process in a water bath canner for 10 minutes.

Canning

Using clean and sterile jars, make sure they are hot before adding the hot jam.

Carefully ladle the warm jam into the jars leaving ¼ inch headspace.

Once all the jars are full, wipe of any excess jam from the rims with a clean, damp cloth.

Place the lids on the jars, ensuring they are centred and flat. Twist on the screw bands until they are fingertip tight. Don’t over-tighten the lids.

Place the jars into a boiling water bath, ensuring they are covered with at least one inch of water. Boil for 10 to 15 minutes, depending on the size of the jars you are using. 12 oz = 10 mins, 16 oz = 15 mins.

Once the jars have finished processing, remove them from the water using a jar lifter and allow them to cool on a towel or rack for at least 24 hours. Once cooled, check the seals and store in a cool, dry place until ready to use. 

This jam should keep for up to one year. 

Refrigerate once open.

Notes

• The more sugar you add, the quicker the gel stage will be reached.
• This is a low sugar blackberry jam recipe. You can make a more conventional jam without pectin by weighing out equal parts sugar and fruit and following the same method of cooking. The yield will be much more if you make the jam this way.
• The amount of sugar and lemon juice does not affect the recipe for safe canning. The measurements for these ingredients can be increased or decreased with affecting it.
• This recipe yields around 2 cups of jam. It may be doubled to make a larger batch, though don’t overdo it as extra large jam batches often have trouble reaching the heat required for reaching the get stage.

Other Jams and Spreads

• Homemade Bread
• Strawberry Jam
• Rosella Jam
• Mango Jam
• Mulberry Jam
• Slowcooker Apple Butter
• Apple Scrap Jelly
• Blueberry Jam
• Lemon Marmalade
• Orange and Lemon Marmalade
• Passionfruit Curd
• Lychee Jam
• Jam Drops