
Our homemade blackberry jam family recipe, prepared as per the traditional French jam-making method.
You'll only need two ingredients: fresh or frozen blackberries and sugar.


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TL;DR
A homemade blackberry jam prepared as per the French jam-making tradition.
French fruit jams contain only fruit and plain, regular sugar. Artificial pectin sugar is not used. They are also not canned, as it's common in North America.
Clean, sterilized jars filled with jam are turned upside down to create a vacuum. The jam preserves well but needs to be stored in the fridge once opened.
We make this jam every year with our home-grown blackberries. It's a smaller quantity because blackberries don't ripen all at once.
We usually collect the ripe berries, rinse them, and freeze them until we have collected enough to prepare a jam.
You can do the same thing or use ripe store-bought berries.

Ingredient Notes
- Blackberries — Fresh, cleaned blackberries or frozen berries. We tend to harvest a bunch, clean, and freeze them batch by batch, until we have enough to make a jam.
- Sugar — Normal granulated unflavored sugar. The cheapest kind will do. Sugar helps in preserving the fruit jam. Note, if you switch sugar with another sweetener, you will end up with a jam that won't keep that long.

Process Overview
Step 1
Rinse your berries and weigh them.
Place the berries with the sugar into a pan, mix, and keep to macerate (to soak for some hours).


Step 2
Take the berries with the sugar to a heat source. Bring to a rolling boil and then reduce heat to simmer down the jam.
Reduce until the fruit looks cooked and the jam appears shiny. That can take 25-50 minutes, depending on the quantity.


Step 3
Blend the jam. After blending, you have the option to strain the jam if you don't like seeds.
Test if the jam is set with a thermometer (The setting temperature is 220 Fahrenheit/105 Celsius) or by dropping hot jam on an ice-cold plate to see if it's set or still running.



Step 4
Pour jam into clean, sterilized jars and close with a lid tight.
Place upside down to create a vacuum and leave it like that until it has cooled down a bit. Store or use as needed.



📖 Recipe

French Blackberry Jam Recipe
Instructions
- Wash your blackberries and pick out any impurities. Weigh the berries and place them into a large cooking pan.4 Cups Blackberries
- Add and stir in all the sugar.1½ Cup Sugar
- Keep the fruits to macerate overnight or for 3-8 hours. (Optional) Macerating helps soften fruits and bring out all the beautiful natural flavors.
- Keep on a medium-high heat setting and bring to a rolling boil. Reduce the heat after that and simmer.
- Cook down your jam, stirring occasionally, until the chunky jam appears shiny, and the fruits look cooked. This can take 30–50 minutes, depending on your heat intensity. You can check the setting point with a thermometer already; it's done cooking at 220 Fahrenheit/105 Celsius.
- Take it briefly from the heat, and blend the jam with a hand blender. You can leave it chunky or smooth.
- If you don't like the seeds, you have the option to strain the jam too. I did not strain since we enjoy the seeds in the jam.
- Take the jam back to a lower heat setting. Test the jam again if it's properly set. Either with the candy thermometer (220 Fahrenheit/105 Celsius setting temperature) or by dropping some hot jam on an ice-cold plate. The jam cools down instantly on the plate, revealing its true consistency. If it's not running, it's set, if it's running, it needs some more simmering.
- Before you fill the jars with the jam, drop a little rum into the lid. That will help in keeping the jam germ- and mold-growth-free. (optional)
- Pour set blackberry jam into a clean, sterilized jar. Clean up with a Wettex or sponge. Close with the lid tight and turn the jar quickly upside down to create a vacuum. Leave the jar like this until it's not hot anymore, and then turn it back upside to label it with the name and date.
- Store the jam in a dry place, away from direct sunlight. I keep them on an open shelf so that we don't forget them at the back of the pantry.
Equipment
- Pan
- Hand Blender
- Candy Thermometer to check setting of the jam. (optional)
- A small Plate left in the freezer 2nd option to test jam setting point.
- 2 8 oz Canning Jars or 236 ml jars.
- Wide Mouth Funnel optional, helps in pouring the hot jam into the jar.
- Soup Ladle to pour jam into jar.
- Silicone Spatula to help you scrape out all the jam from the pan.
- Wettex Absorbent Sponge to clean jars if you made a mess.
Nutrition
Uses
You can add a spoonful of blackberry jam to your plain yogurt as a dessert or spread some on your morning breakfast bread to start the day.
Also, try adding some blackberry preserves to baked goods or as a filling to stuffed doughnuts, pastries, and cookies.
Storing Instructions
Store your unopened jars of blackberry jam on a pantry shelf, away from direct sunlight and moisture. They will keep for ten to twelve months if prepared the French way, without a water bath.
Once you are done filling them with the blackberry jam, you can follow the FDA-approved canning instructions and put your jam in a water bath.
This will add another layer of protection and increase the jam's shelf life. We generally don't do this in Europe.
In humid, hot places, keep the jars in a cool, dry place all the time or in the fridge. Once you open the jar, put it in the fridge. Avoid double-dipping, as it can lead to the growth of mold and is unhygienic.


FAQs
There are a few reasons why your blackberry jam can turn out runny. Your fruits are not sour enough. Store-bought hybrid blackberry varieties tend to be sweeter.
Wild and homegrown blackberry varieties are sourer. Quick fix: Add 2-3 organic lemons with the rind and lemon juice, that will help in adding natural pectin without much effort. You tried to double the batch. It's easier to work with a batch of 1-kilogram fruits. Trying to jam more than a kilogram at a time can complicate things. You reduced the amount of sugar in the recipe because you thought it contained far too much sugar. Don't ever reduce the sugar in a jam recipe, especially when it's without pectin. The sugar is key to jam and helps in the jelling and storing so that the jam doesn't turn bad. You didn't give your jam a rolling boil, or you didn't cook your jam long or high enough. In that case, use a thermometer. You used a pot that wasn't giving uniform heating. Some jam got cooked less, some more, that shouldn't happen. That is why you might want to use a pan like the French copper pans.
The blackberry jam setting temperature is 220 degrees Fahrenheit (105 °C).
A hard jam means it has been overcooked. It's more difficult to fix a hard jam. You can take it back to the heat with a small quantity of water to mix in. Briefly cook and pour the jam into a jar to store, but make sure to use the jam within a few weeks because it won't keep that well, since you had to add water.
More Berry Jams
The post Blackberry Jam was published for the first time at maslaherb.com on September 17th, 2014, and has been enhanced and updated ever since.

Thank you Helene for the recipe and for saving my 1st runny jam with your advice!
The fisr time I cooked it I didnt have a thermometer and I'm sure I had not reached the proper temperature: it yielded 3 jars of blackberry juice (really). Helene said it was ok to throw it back in the pot and watch the temperature carefully this time & wash/sterilize the jars again to be safe. I did jist that and oh boy! It worked out perfectly and this time I got about 2 and 1/4 jars.
I'll be using it again for sure!
Bianca, I'm glad it worked out after all! =D I know at the beginning I used to always make my jam without a thermometer but once I messed it up and since then I use always a thermometer. Thank you Bianca, for taking the time to share your experience. Much appreciated and I hope your experience and knowledge will be useful to others in the same situation.
Helene, merci pour la recette! I just tried it and unfortunately it's too runny. Maybe it didn't reach the proper temperature...i didnt have a thermometer to help 🙁
Question: is it ok to throw it back in the cooking pot and cook it for a little longer?
Hi Bianca!
I'm sorry to read that your jam turned out runny. Yes please, take it back to the heat and try to use a thermometer or do the cold plate/spoon test with the hot jam. so that you know when it' s set. Also, wash the jars again and sterilize well before filling up your jam again. Be careful to not overcook the jam accidentally (that can happen when you undercooked it first out of fear). It's always easier to fix a runny jam. All the best and let us know how your jam turned out at the end. 🙂
I loved making this jam so so easy I love blackberries can not get enough of them .thank you for this cooking tip.
Thank you for your feedback. It's great to know that you enjoy the blackberry jam as much as I do.
how long does it keep, and can it be frozen?
The Blackberry Jam is good for a year if you keep it unopened in a cool and dry place (by having sterilized the jars and added alcohol into the cap to get rid of germs etc). once you open it, store in the fridge and usually it will be still ok too after 10 months, but the jam might get dry-ish. Freezing jam is not necessary because it's a traditional recipe and the sugar amount in the recipe preserve the jam without a need for freezing.
This was perfect blackberry preserves. I appreciate the weights. I switched my scale from ounces to grams, and voila! Your many tips, especially to use less ripe fruit for natural pectin worked beautifully. Mine took a long, long time to reach 220F, and after 1 hour of cooking my preserves wouldn’t rise in temperature beyond 214F. I increased the heat from low to medium, and then it was done in less than 4 mnutes. Many thanks!
Happy to read that it worked out well. =)
With the time and temperature it can depend also on the stove you use and the pot.
In that case, the way you handle it was the way to go. A thermometer can be super useful.
Thanks for taking the time to come back and leave a comment, much appreciated!
Do you have a conversion chart for measuring. I'm from the Mid-US and we use cup, tablespoon, tsp, etc. I usually have loads of berries. I love to cook.
Hi Linda,
For the blackberry jam you can use 4 1/8 cups fresh Blackberry and 3 3/4 cups sugar. I will be adding US measurement to my posts soon, so it will be easier to follow the recipe for you.
I'm right there with you Helene on the GMO issue. I was at a conference last week and heard that a group of researchers are trying to develop a chile where all the fruit on the plants are the same shape and size so they can be picked by machine, not people. There are SO many things wrong with this! There is something so real and natural making jam this way and the results are better than anything you could buy at the store. What a beautiful jar of jam!
Blackberries grow like crazy here in the Pacific Northwest - they are everywhere, so we pick them and freeze them (and make jam!). Unfortunately, they're an invasive species - not native to the area, and they pretty much take over when they start growing. Much as I like the berries (and jam!), they're a real problem. (One example is when they move into streams, they get rid of the plants that create the shade that allow salmon to spawn).
Your jam looks lovely! Pectin is not needed for jam!
What gorgeous black jam, I would be spooning 😛
Who needs toast right?
Cheers
Choc Chip Uru
Good to know this requires no pectin! Don't like the stuff at all. It looks divine!
The jam looks too tempting. Just can't believe that it is made without pectin!!
Helene, your jam looks outstanding... so delicious! I eat with all my senses!
This jam - wow - I could eat the whole jar!!!
I -too- use all my sense and much rather have food that tastes delish and is nutritionally dense.
That is one of my favorite jams! Lovely.
Cheers,
Rosa
I would love to say I used all my senses but sometimes it's just smell and taste. I should think about it more. Outstanding blackberry jam.
that looks delicious. So pretty and I cant believe it doesn't have pectin in it!