Blackberry jam recipe, how to make preserves without pectin

We all love old fashioned blackberry jam, even if it is a really easy recipe it has a few small tricks to make it irresistible.

The techniques I’ll explain here could be applied to any jam, especially to berries jams, like raspberry jam or blueberry jam

If it’s your first time making jams I recommend you read all the post, so you can understand better all the process and have the best results. Try with a small batch recipe.

As I’ve mentioned before, before having this recipe blog, I had a jam-making business called “La cocina de Mila,” so I can speak from experience and give you various tricks and tips for jam recipes.

How to Make Our Own Jam: 

Jam making was born as the simplest way to preserve fruit, especially when it’s too ripe, for the winter. Preparing this jam has a few tricks that I’ll explain below:

  1. As a general rule, when making jam, you use equal parts of white sugar and processed fruit (which would be the washed fruit without seeds or peel). This ratio can vary up to twice the weight of fruit to sugar. For me, the perfect amount of sugar or ratio for making blackberry jam is 8 parts of granulated white sugar per 10 parts of fresh blackberries. Remember that sugar not only serves to sweeten jams but also helps with preservation. I won’t get technical/boring and talk about pH, Brix degrees, and such things, but think about how long white sugar can last in a sealed jar. It stays perfectly preserved, right?
  2. If you like chunks of blackberries in the jam, what you’ll do is mix them with the sugar in a large pot, cover them, and let them rest for several hours at room temperature until they release their juice. Then, cook them over low heat, so the fruit doesn’t break. If you prefer that your jam be more mashed then press de fresh berries with a potato masher during the coking process.

How to Know When Our Blackberry Delicious Jam Is Ready: 

There are several ways to know if our jam is ready or at the right point, ranked from the most to the least precise method:

  1. By temperature: When the jam reaches 104 to 105°C or 220°F (assuming you’re at sea level). 

2. Take a spoonful from the pot and spread it on a cold plate to cool. Then, sprinkle granulated sugar on top. If it doesn’t sink or get wet, the jam is at the right point. 

3. Put the same spoonful of jam on a plate and let it cool. Then, “draw a line” with your finger by passing it through the middle. If, after a few seconds, it doesn’t come back together, the jam is at the right point. 

How to Store and Preserve Our simple blackberry Jam: 

If you’re making a small amount of jam and will use it soon, the easiest way is to wash glass jars with hot water, let them dry upside down, and then fill them with our hot jam. Once it’s cool, cover it and store it in the refrigerator. Under these conditions, our jam should keep well for up to 1 month.

Now, if you want to store jam jars in the pantry for a longer time, you need to understand certain concepts:

If the jam is at the right point and has the right fruit/sugar ratio, it shouldn’t ferment. That’s why our main enemy when preserving jams is mold. However, if we understand mold, we’ll know how to preserve it longer (side note: mold is ugly but not that bad) If your jam develops mold, you can simply remove it along with about an inch around it, and the jam below should be fine.

Mold needs food, the fruit in the jam, and there’s nothing we can do about that. It also needs liquid, so it’s important that our jam is at the right point. This reduces the likelihood of mold growth. Lastly, it needs oxygen (air), and that’s where we have some room to “play.”

So, we need to find a way to reduce the air that comes into contact with our jam:

The technological way: Wait for the jam to cool and then put it in vacuum-sealed bags using a vacuum sealer. If you don’t have a vacuum sealer, please disregard this option. I’ve heard of people using ziplock bags, closing them almost entirely, and leaving a small opening where they insert a straw to “suck” out the air with their mouths. Please don’t do this, as the mouth is one of the most “contaminated” parts of the body, and who knows what you might introduce into the bag/food. 

The brute force (and no less effective) way: Put the jam in sterilized jars. When it’s cool, light an unscented and colorless candle and let the wax drip directly onto the jam, forming a layer about a finger thick. This prevents it from coming into contact with air. When you want to eat the jam, gently break the wax layer with a knife and remove the pieces. This method is ideal when you don’t have jar lids. 

The “traditional” way: You should fill sterilized glass jars when the jam is still hot. Then, close the jars of jam and turn them upside down so they stand on the lid. Watch to ensure that no bubbles are moving. If there are bubbles, it means the jars weren’t properly sealed. As they cool, they should become vacuum-sealed due to the temperature change. You’ll know they’re well sealed if the lid is slightly depressed.

 How to Sterilize Jars for Canning Jam: 

I’ll start from the basic assumption that you don’t have an autoclave, UV lights, or anything strange/technological/industrial.

The simplest way to sterilize is with heat, and here you have two options:

Dry heat (my favorite): Wash the canning jars with water and detergent, let them drain, and place the clean jar in a tray with the mouth facing up (use the same trays you would use to bake cookies). Put them in the oven and set it to the maximum temperature. Once the oven reaches 150°C or 300°F, turn off the oven and let it cool the hot jars with the door slightly ajar before removing them.  Make sure that de jars are good quality and can tolerate heat.

With boiling water: This is the most popular method, but I find it more complicated in practice. Place the jars in a pot with cold water. The pot should be deep enough so that the jars are completely covered by water. Cover the pot and heat it over high heat until it begins to boil. Count to 3 minutes and then turn off the heat. With the help of tongs and a lot of care, remove the jars without touching them with your hands. Discard any water they might contain and let them cool upside down on a rack until they’re cool and dry.

To clean the lids, wipe the interior with a gauze soaked in alcohol.

Substitutes and Additives for Our Strawberry Jam:

The most logical question here is, “Can I make jam without sugar or with less sugar?” and the answer is YES, but there are several caveats to this adaptation. As I mentioned, sugar not only sweetens our homemade blackberry jam recipe but also aids in its preservation and provides volume. So, it’s not as simple as replacing sugar with a sweetener. We need something to increase volume, and there are various methods, but the main ones are:

Add grated apple. Due to its high fiber content and being a high pectin fruit, it’s perfect for adding volume. Ideally, the ratio should be 1 part grated apple to 2 or 3 parts ripe blackberries. Then, sweeten to taste. The issue with apple is that it will contribute its own flavor. 

Add a gelling agent. It could be flavorless jelly previously dissolved in water or agar agar. This will help our “jam” thicken. Regarding the sweetener to use, I’ll be quite categorical: use stevia. It performs well at high temperatures, and it’s also quite affordable and easy to find in any grocery store.

Note that even so, our homemade sugar-free jam won’t keep as well as traditional jam. That’s why you need to refrigerate it in a sealed glass jar, and it will last between 7 and 10 days.

If you want to make a seedless jam:

The easiest way is to mix the sugar and ripe berries in a pot, put on medium heat, and wait until it starts to boil, then stop the heat and carefully mash the jam with a potato masher. Then pass the mixture in a strainer to remove the seeds. Finally, continue cooking until the jam is ready.


natural pectin is a compound found in fruit seeds that gelifies (similar to traditional jelly). The benefit of adding it to jam is that it will reach the right consistency in less time and preserve better. You have the option to buy synthesized pectin “in powder form” (it can be synthesized at home, but it’s a hassle). However, before using it, you need to be clear about two things: First, it gelifies in the presence of acid. So, if you add it and it doesn’t thicken quickly (3 to 5 minutes), you need to add something that rise the acidity levels like lemon juice, orange juice, or mandarin juice instead of more pectin. Second, it starts to gelify very quickly when in contact with liquid. That’s why you should mix it with the sugar before adding it to the pot. If you added pectin directly to the pot, it will form a ball of “gel” that will be technically impossible to undo. The amount of additional pectin you need will vary greatly from brand to brand, so check what the package of the one you buy says.

If you are interested in preserving fruit, I recommend this recipe of cherry syrup, and If you want to do another recipe with blackberries try this delicious kuchen.

Blackberry jam recipe, how to make preserves without pectin
5 from 1 vote

Blackberry jam

We all love old fashioned blackberry jam, even if it is a really easy recipe it has a few small tricks to make it irresistible.

Course jam
Cuisine Internacional
Keyword blackberry jam, blackberry jam without pectin, jam without pectin, old fashion blackberry jam
Prep Time 4 minutes
Cook Time 30 minutes
Servings 2 pounds
Calories 400 kcal


  • 1 pound rip blackberries
  • 1 pound granulated white sugar


  1. We put the blackberries and sugar in a large pot. If you like your jam to be left with whole pieces of fruit, cover the pot and let it sit overnight. If you prefer the jam to be a more homogeneous "paste" you can start cooking it right away.

  2. Cook the jam over medium heat, stirring occasionally until it begins to boil, at which point reduce the heat to a minimum, and continue cooking and stirring occasionally until you have the texture of jam (which is on point). To see the point of the jam, it exists in many ways, I will explain 2 ways that are similar, in an extended dish we put a spoonful of jam and let it cool without stirring at room temperature.

  3. When the jam is cold to see the point we can a) sprinkle granulated sugar on the jam, if it does not sink the jam is already point or b) we pass the index finger through the middle of the jam, if the jam does not go back to to join completely is that it is well knitted.
  4. If we will consume the jam soon, we pack it and when it is cold we refrigerate it covered.
  5. If we want to save jam for the year we will have to sterilize glass jars and vacuum seal them, there are several ways to explained in the post.

Nutrition Facts
Blackberry jam
Amount Per Serving
Calories 400
* Percent Daily Values are based on a 2000 calorie diet.

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