Fresh blackberries, sugar and lemon juice are the ingredients needed to make this delicious jam! No added pectin is needed as wild blackberries are naturally high in pectin.
This seedless blackberry jam is perfect for using on toast or in sandwiches.

This recipe has been updated to reflect additional information and now includes lemon juice. The lemon juice helps the jam set. I have had success with and without the lemon juice, but this can vary depending on your blackberries. I recommend adding the lemon juice to help ensure your jam sets up.
Why make this jam
We have been picking wild blackberries like crazy. Rod told me we have over 8 gallons in the freezer!
Homemade jam is just one way to fully enjoy these amazing berries.
I've also been making Blackberry Muffins and Seedless Blackberry Jam. Another favorite is Blackberry Pie Bars and Blackberry French Toast
Several years ago I made blackberry jam, but left the seeds in. The jam was delicious, but the seeds seemed really large. I actually thought the jam was hard to eat. Making this jam seedless took an extra step, but was well worth it!
You have several options once you make homemade jam. You can refrigerate and eat it within one month. You can freeze it in smaller portions and pull out when you're ready to eat or you can can it in canning jars and preserve in a hot water bath and keep on your selves in your pantry for up to a year!
I've included instructions for making the jam and for canning the jam!
Key ingredients
- Blackberries - fresh or frozen. If using frozen, allow berries to thaw first. Be certain to keep all the juice that is released as the berries thaw.
- Sugar
- Lemon juice
Pectin
Pectin is a naturally found substance in many berries and fruits. It is also produced commercially to aide in setting jams and jellies. Commercial pectin requires an exact amount of fruit and a high amount of sugar in order for the jam or jelly to set.
Lemon juice and sugar is added to help activate the natural pectin
Blackberries are naturally high in pectin so no added pectin is needed. I always add a few reddish blackberries into the mix because they have even more pectin than the riper black ones.
Because this recipe doesn't use a commercially added pectin, the amount of sugar added is all up to you! I added 4 cups of sugar to 8 cups of strained fruit. Most jam recipes call for equal amounts of sugar to fruit!
Feel free to adjust the sugar to your liking.
Step by step directions
- Mash berries and strain seeds
- Place strained berries, sugar and lemon juice in a pot over medium high heat
- Stir often to avoid scorching
- Heat until jam reaches the gel stage
- If canning, place jam in clean and sterilized jars
- Wipe rim clean
- Add lid and screw cap and process in a hot water bath
How do I know when my jam is done?
Knowing when your jam is set, or done is the hardest part of making jam.
When cooking without commercial pectin you need to rely on a spoon test, a plate test or check the temperature. I like to use at least two methods, and often all three methods when making jam.
Spoon test
The spoon test relies on watching the sheeting or drops as they come off the spoon while it is cooking. When the jam first starts boiling it comes off in drops or thin steams.
When the jam has set, the jam will come off the spoon in more of a sheet. This takes some time to learn what this looks like and even though I've been making jam for years, I always rely on a second method.
Plate test
Have a small plate chilling in the refrigerator. When you think the jam has set, place a spoonful of hot jam on the cold plate. Wait one minute and draw a line through the center of the jam. If the line holds its shape and doesn't run, the jam is set.
Temperature test
The temperature test is the most reliable. However the exact temperature will vary, depending on your altitude. You will deduct 2° for every thousand feet above sea level. Jam sets at 220° at sea level. I'm at about 2000 feet above sea level and my jam sets between 216° - 218°
I usually watch my jam with a thermometer and when it starts getting close to 215° I begin doing a sheeting test and then the plate test. I don't like to rely on just one method.
Tips for making jam
- Blackberries are very messy and the juice will stain. Wipe up spills and drips quickly and wear something you don't mind if a few stains remain.
- Use a pot that is a least double the size of the ingredients. When you boil jam it will really swell up in the pot.
- Keep a close eye on your jam. You don't want it to burn or boil over. The pictures below show my jam boiling all the way to the very top of a large pot. If this happens, turn down the heat, blow gently on the top of the jam and carefully stir the jam. You don't want it to boil over and lose all that jam and have a burnt sticky mess to clean up.
- Jam will often create foam when boiling. I just ignore the foam. It usually disappears once the jam is set. If you still have foam on top of the jam, you can skim off before canning your jam.
A few tips when canning jam:
- Make certain you always clean and sterilize your jars prior to using.
- Use new canning lids that have been washed.
- Hot water bath your jars according to the size of your jars and always adjust for your elevation.
- Once jars are sealed and cooled for 12 hours, remove rings and wash jars. Replace rings if desired.
- Label and date jars.
Canning Supplies
A few supplies you may need to make this jam include Canning Utensil Set, Food Press(or chinois) Large Pot, Thermometer and Canning Jars.
If you'd like to freeze excess blackberries, follow these steps for freezing raspberries.
Some additional jam recipes for you to try include Apricot Jam, Rhubarb Jam, Strawberry Jam and Plum Jam.
If you make this recipe, I’d love to hear about it! Leave a comment below and snap a picture and tag me on Instagram @beyondthechickencoop
Check out all my Canning Recipes.
Seedless Blackberry Jam
Ingredients
- 12 - 14 cups blackberries (ripe berries and a few unripe berries)
- 4 cups sugar
- 2 tablespoons lemon juice
Instructions
- Mash and strain seeds from blackberries using a chinois. Measure out 8 cups of strained fruit for jam.12 - 14 cups blackberries
- Put 8 cups of fruit, sugar and lemon juice in a heavy stockpot over medium heat.12 - 14 cups blackberries, 4 cups sugar, 2 tablespoons lemon juice
- Stir until sugar is dissolved. Continue cooking over medium heat until mixture comes to a boil. Stir every few minutes to prevent scorching.
- Boil until jam is set (220 degrees at sea level and -2 degrees for every 1000 feet above sea level.. 1000 feet 218°). Jam needs to reach temperature in order to thicken. Stir often to prevent scorching. Remove from heat. Ladle into clean, sterilized jars.
- Wipe down rims and add canning lids and rings. Place in a hot water bath and boil jars for 10 minutes (adjust time according to elevation - see notes below)
Notes
- Be certain to add some unripened, or reddish berries as well as the ripe blackberries. The unripe berries have higher levels of pectin.
- Cooking time will vary depending on your elevation and your stove.
- I used pint sized jars (2 cups.) You can also use ½ pint size jars.
- Be certain to adjust water bath times according to your elevation.
Misty says
Can I put the blackberries in a good processor to get rid of seeds?
Kathy says
Hi Misty,
I have not tried putting them in a food processor. Let me know if you give it a try!
Kathy 🙂
dawna stice says
I made the jam yesterday and it is great! I cooked it a little too long because I wanted to make sure that it's set up so I had to thin it down. But this is one easy great recipe!
Kathy says
Hi Dawna,
Thanks for your comment! Blackberry jam just makes me think of summer!
Enjoy!
Kathy 🙂
Angela says
Hi Kathy
Thanks for your help
I think I may have made it a little sweet??
I had 2325g of fruit with seed and added 750g of sugar and macerated it overnight
After warming it and mashing it I had approximately 8 cups of juice and then added 2 cups of sugar
It made lovely jam
How much sugar would you have added after maceration??
Bumper year for blackberries
I might go out again before the end of September lol 😁
Kathy says
Hooray for so many blackberries. I'm afraid I haven't made the blackberry jam in the way you describe so I don't know what the ratios of sugar should be. If you felt it was too sweet, I'd cut back the amount. Try tasting the juice after macerating and see if it needs any additional sugar at all.
Kathy 🙂
Angela says
Thanks Kathy
Now that it’s set and been refrigerated I am finding it very thick and hard to spread
Any ideas on how to make it thinner at this stage??
Kathy says
Yikes! How is it at room temperature? Still too thick? You might try this strategy from Nation Center for Home Canning
They suggest, "Stiff jams or jellies can also be warmed for use as pancake or ice cream syrups.
Stiff jams or jellies can be thinned with water or fruit juice. They may or may not form a gel again once they are re-heated, as over-cooking of pectin can reduce or destroy its ability to form the gel structure."
Kathy
Sydney says
I love how easy this recipe is, although my jam was very thick and I had to eat it right after I made it.
I'm excited to try again with more berries!
Kathy says
Thanks, Sydney!!! 🙂 When you make it again, keep an eye on your jam and try to determine when the jam is done by using the spoon test and the plating test. Reaching 220° might be too high for you. I usually keep an eye on all three testing methods when I make my jams...every time it's just a bit different!
Enjoy 🙂
Lisa G says
Can I use frozen blackberries from the store?
Kathy says
Hi Lisa,
Frozen blackberries from the store should work.
Kathy 🙂
Carolyn says
I made this delicious jam last night. I was a bit worried about it not setting and had to add extra lemon juice. I struggled to get the temp up to 220 without it boiling over. I didn't add many unripe berries which is likely what caused the problem. Im so happy to have fresh blackberry jam without all the seeds! thanks for
Brenda says
How much water goes in the water bath?
Kathy says
Hi Brenda,
You'll need enough water to cover the top of your jars by at least one inch.
Kathy
Kate says
Hello! I finally have enough wild blackberries to make this, this weekend. I see some recipes use lemon juice. Have you tried this one with it, if so, how much do you suggest using? Thanks!
Kathy says
Hi! Yes, you can add 2 tablespoons of lemon juice. I have updated this recipe to reflect added lemon juice.
Enjoy! 🙂
Ann Mather says
My jam is in the canner right now. It looks and tastes great. I have a bumper crop of blackberries this year and this is my third batch. I am glad to have advice about using less sugar than other recipes. It never did reach 220 degrees but I did the spoonful in the freezer test, plus the spoon test. Thanks!!!
Kathy says
That's great!!! Lucky you to have so many blackberries! Thanks for your comment 🙂
Christina Marie Perlowski says
Is this freezer jam or when you use the hot water bath it's good to keep in pantry?
Kathy says
Hi Christina,
The hot water bath makes this shelf stable so you can store in your pantry.
Enjoy!
Danielle says
Help!! I used this recipe and mg jam was extremely runny. What should I do? It was k on blue juice from the blackberries, no seeds or pulp!
Danielle says
It was all pure juice, no pulp
Kathy says
Hi Danielle,
You may need to cook your jam longer for it to thicken.