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.
- Put 8 cups of fruit, sugar and lemon juice in a heavy stockpot over medium heat.
- 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.
Rebecca Smith says
I cooked until 220 degrees, but it is not setting up. Can I empty the jars and cook longer?
Kathy says
Yes, you can. Try using the sheeting method or testing on a cold plate.
peggy courtney says
it says to adjust the water bath time according to the altitude, so where do i find that info.
Kathy says
Hi Peggy,
Here are the guidelines for adjusting to altitude when water bath canning above 1000 feet:
1,001-3,000 – increase 5 minutes
3,001-6,000 – increase 10 minutes
6,001-8,000 – increase 15 minutes
8,001-10,000 – increase 20 minutes
Ellen says
HELP ,!Please, I am making this now but as i hand mash berries, they are very thick. What is the easiest way to remove seeds? Thank u
Kathy says
Hi Ellen,
Place in a fine meshed strainer or if you have a chinois use that. For the strainer, use the back of a heavy spoon and push the pulp through the sieve. If the berries are too difficult and thick, heat them over a low heat until the berries begin to break down. Then place them in the strainer.
Hope that helps!
Kathy
Tamera says
Thanks for this recipe. I impelling all my frozen Blackberries from last year out of the freezer this week since my bushes are blooming and i know in another month and a half or so ...it will be time to start picking again!
Kathy says
What a lovely problem to have! I need to do the same thing with blackberries and raspberries! Let me know how the jam turns out.
Enjoy! 🙂
Sheryl says
I have cooked my jam at 220 degrees and it is not thickening? What am I doing wrong?
Kathy says
Hi Sheryl,
I'm sorry I couldn't get back to you right away. Hopefully you cooked it a bit longer and it thickened. Let me know how it turned out.
Kathy
Crystal says
Making this tomorrow to put in a cake, is the hot bath step necessary? Or can i just make it, set it aside to cool in a bowl, then straight into my cake?
Kathy says
Hi Crystal,
You only need to water bath the jars of jam if you are intending to store for an extended period of time. If you are using right away, you can skip that step. Using in a cake sounds like a delicious idea!
Enjoy,
Kathy
Crystal says
Amazing, thank you! I just made it, i think i cooked it a little too long though, it's super thick...! I was so worried it would be runny i went the other way lol
Amrita says
This recipe looks wonderful! How long does the jam last once canned?
Kathy says
Hi Annita,
Canned jam lasts for up to two years. Just always make certain you check to make certain the jar has remained sealed and the jam should last. To preserve the color, store in a dark place.
Enjoy,
Kathy
Peggy says
I started with 4 cups strained juice/pulp so I halved the recipe ....since I hadn’t picked quite as many berries.... yet. This makes a very concentrated Luscious jam. It made 2 1/2 cups jam. For my next batch I will put in even less sugar. Great jam! Just can’t resist the berries all over Oregon while visiting my daughter. Cooked to 220F and was very thick at 400 ft elevation
Kathy says
Oregon certainly has lots of wild blackberries. Lucky you to have access to them!
Juliana says
Hey there ! I love this recipe! Just wanted to ask if I could make jam from frozen blackberries . I’m picking so many that I don’t have room to make anything else, but I would like to freeze it and when I run out, i wanted to know if that’s ok to make some more from the frozen ones. Thank you!!
Kathy says
Hi Juiliana,
Yes, you can use frozen blackberries. You'll want to thaw them first before making into jam.
Enjoy!
Kathy
Rosemary Parson says
I cooked this to 220 degrees and it was very thick! In fact, next time I might stop a bit before 220 degrees. I had 12 cups of blackberry puree and used 6 cups of suger, plus a few tablespoons of lemon juice. I ended up with 3 and 1/2 pints of jam.
Kathy says
Hi Rosemary,
Here's some additional information about the temperature of jam from the National Center for Food Preservation: When done, the temperature of the jelly should be 220°F, 8°F above the boiling point of water, if you are at sea level. NOTE: For each 1000 feet of altitude above sea level, subtract 2 degrees F. For instance, at 1,000 feet of altitude, the jelly is done at 218°F; at 2,000 feet, 216°F, etc.
This could be why yours turned out thick.