Marsha's Favorite Jam Recipe

(From 2016 with 2025 updates.) I decided to document my current favorite way to make jam because I have tried different ways and had mixed results in the past. Sometimes it's great, sometimes it's runny, sometimes it's bubbly (???!!!), etc. But, I have made three kinds of jam this summer using the same technique and so far they have all turned out fantastic. To the point that Scott even said, "I think you have mastered jam." Yay! So, here goes.

Homemade Jam

(Strawberry, Raspberry, Blackberry) 

Ingredients:

• 4 pints (or 30-32 oz.) berries (equals 3 1/4 cups crushed berries), washed and debris removed (for strawberries, quarter the berries for easier mashing)
• 1 box MCP Pectin
• 1/4 cup lemon juice (fresh or bottled)
• 4 1/2 cups sugar (added later, see recipe)
• 1 cup corn syrup (added later, see recipe)
• For storage of the jam, I use five 16 oz. (2 cup) containers

Directions:

1. Crush fruit to your desired consistency.
• I like chunks of fruit in my jam, so I used a potato masher for raspberries and blackberries. Sometimes strawberries are harder to crush with a potato masher, so with larger berries I will quarter them and then use an immersion blender sparingly to blend some of the fruit, while still leaving some bigger pieces. 
2. Gradually mix crushed fruit with pectin and lemon juice. 
• One time I messed up at this step and starting adding my corn syrup as well, but in the end, the jam turned out just fine. However, technically, you add the sugar AND the corn syrup later in the process.
3. Let sit for 30 minutes, stirring every 5 minutes. 
4. Mix in corn syrup (according to the package, this is supposed to help with crystals forming during freezing). 
5. Slowly add sugar. 
6. Pour into containers, cover with lids, and let sit on counter for 24 hours. Freeze or use immediately.
• The jam should start to thicken within a short period of time (an hour or less) so be sure to put it in your containers and not leave it sitting in the mixing bowl for very long.

Marsha's Tips:

Without knowing for sure, I imagine part of my jam-making success was strictly following the "stir every 5 minutes for 30 minutes" pectin step. It sounds like a pain, but it made GREAT jam.

Fruit Container Measurements-

• Strawberries: Currently, our store sells strawberries in 16 oz. containers. A flat of strawberries is eight 16 oz. containers, which will need four boxes of pectin, an entire 32 oz. bottle of corn syrup, 18 cups of sugar, and 1 cup of lemon juice (about half of a 15 oz. bottle). It will make about twenty 2 cup containers of jam.
• If you wanted a single batch of jam using only one box of pectin, then you would only need two of the 16 oz. containers of strawberries and not an entire flat. You would end up with about five 2 cup containers of jam.

16 oz.

This shows what supplies I bought and had on hand for making jam, including the flat of strawberries (one more larger bottle of corn syrup not pictured).

• Blackberries and Raspberries: Both of these currently come in 6 oz. containers. You need five or six of them to make a batch of jam that uses up one entire box of pectin, plus about 1/2 of a smaller 16 oz. bottle of corn syrup, along with 4.5 cups sugar and 1/4 cup lemon juice.
• I bought six 6 oz. containers of each kind of berries (see in above picture) and ended up with more like 4 cups of crushed fruit in the end, so five would have been closer to the recommended amount of fruit per package of pectin... but in the end, it seemed to turn out just fine even with a little extra fruit. The blackberry seemed to tighten up nicely, and the raspberry was runnier, but still fine. If it turns out problematic after freezing and then thawing the jam, I will try to remember to come back and report.

6 oz.

6 oz.

Here are some pictures to show my process:

Here are all six containers of blackberries, washed and ready to go.
I set this strainer full of berries inside of one of my biggest mixing bowls and filled the entire thing up with water so I could stir the berries around and get the bits of leaves and things to float to the top of the water so I could pick out any debris. Initially, if any of the berries appeared to have any mold on them, I removed the moldy berries and then added just a touch of white vinegar (2 Tbl to about 1/4 cup) to the water to help sanitize the remaining berries. I would let the berries sit in the vinegar water mixture for just a couple minutes. Then I pulled the strainer with the berries out of the water in the larger bowl and rinsed everything again off with my faucet sprayer and let sit and drain for a minute or so. 

Clean berries crushed with a potato masher.

As you can see, six packages of berries made about 4 cups crushed, so five probably would have been closer to the recommended 3 1/4 cups berries. So in the future, I will use 5 packages.

Raspberries washed and ready to go.

Crushed, these also made about 4 cups, similar to the blackberries, so again, I would only get five containers next time.

Strawberries getting their final rinse before being stemmed and quartered. Because there are so many strawberries, I did them two 16 oz. containers at a time, washing, rinsing, stemming, and mashing in batches.

Some of the berries I started to slice and then realized that I didn't need to go to that much work if I was just going to mash them, so I quartered the rest of the flat instead.

Mashed with a potato masher. There are still lots of big chunks that were hard to mash up very well this way, so I decided to try the immersion blender instead, which worked well. 

You can see here that two containers made about 3 1/4 cups almost perfectly, so that is what you need to use one box of pectin.

Sporadically using the immersion blend to get some of the larger pieces chopped up, without blending the entire thing because I like some pieces of fruit to remain intact in the final product (you could probably also use a regular countertop blender for this, using the pulse feature so you can control how blended up everything gets).
After trying the potato masher with that first batch of strawberries and deciding that was too much work, I just added my quartered strawberries directly to this red bowl and processed them entirely with the immersion blender moving forward.

Here is the entire flat done. But this bowl is too small to hold the strawberries AND all the sugar and other things to make the jam, so I had to transfer it to another REALLY BIG container (but this container is plastic and I would be afraid to use the immersion blender in this blue tub, so I would still use the red bowl for mashing the berries in the future because it's ceramic).

Berries all mashed and ready for pectin and lemon juice. Then comes stirring every 5 minutes for 30 minutes before adding the corn syrup and sugar later. I found that tucking the handle of my whisk into the handle space of the blue tub kept my whisk from falling into the strawberry mixture between stirrings.

After the pectin has processed and all the other ingredients are added, it's time to divide everything into containers. This worked really well with my large canning funnel and a soup ladle. Between the jam being finished and when I put them in the containers, I stopped to eat dinner and was surprised by how much some of the jam had thickened up already, so don't wait too long to get it all divided up in the containers and ready to sit for the night.

All divided! As you can see, I got 5 raspberry, 5 blackberry, and 19 strawberry. If I had divided things more precisely, I probably would have gotten 20 containers of strawberry.

Lids cleaned and marked, ready for the jam to sit out overnight before freezing.

These are the supplies I had leftover:
I had a partial bottle of corn syrup in the house, so I bought both a full 32 oz. and a 16 oz. bottle for this project. I used all of the full 32 oz. bottle (for the strawberries) AND 16 oz. bottle (for the raspberries and blackberries) of corn syrup, leaving me with that partial 32 oz. bottle that I had from before.
I had a partial bottle of lemon juice (about 1/2 full) so I bought a new 15 oz. bottle. I used all of my partial bottle of lemon juice and part of the new bottle I purchased. It should take less than a 15 oz bottle to make 6 boxes of pectin into jam, just for reference.
I had one old box of pectin, plus I bought eight more boxes because I wasn't sure how much I needed. It turns out for all this jam I needed 6 boxes, so I had three leftover.
For sugar, I have a huge storage tub of sugar in the basement that I dip out of to fill my kitchen sugar container, and I had to fill my container twice from my large supply to get all of this jam made. In total it was 27 cups of sugar. My kitchen container probably holds a 4-5 lb bag of sugar, so if I was buying smaller bags of sugar for this project I would get at least two... maybe three.

I also realized that some of the members of my family live alone now and probably won't want an entire larger container of jam, so I bought some of these smaller containers and dipped out of a couple of the bigger ones so I could give out smaller portions to anyone who wanted it. I would have needed 12 total smaller containers to use up all three of those larger containers. The larger containers are 2 cups (16 oz.) and the smaller are 1/2 cup (4 oz.).

Notes from before 2025: The history of figuring out pectin-

• As I mentioned, I have had mixed results in the past, so this time I even took a picture of the box of pectin I used because not all pectin seems to be the same. They even have different kinds of Sure-Jell pectin, one of which is clearly labeled for lower sugar jam recipes, but two of them have different names with no real indication on the box what the difference is; Sure-Jell vs. MCP. 
• I Googled it, and it appears I am not the only one confused. Here is what one lady wrote, "I went to the Albertsons, and they had the Surejell right next to MCP pectin, and I got very confused. MCP is made by Surejell. Surejell is 1.75 oz at $2.99 a box. The MCP is 2.0 oz for $2.49 a box. More for less? I called Kraft and asked about the differences, and they said the formulas were different. Sure enough, I checked the back of the boxes, and Surejell lists dextrose, citric acid, then pectin. MCP lists dextrose, pectin and then citric acid. I have my formula for jam dialed in, so I didn't want to "mess with success" and switch now, with just one batch to go, but now I'm wondering what, if any, are the differences in the products?" Even the Kraft website (who makes Sure-Jell) lists the same description for it's Sure-Jell pectin and it's Sure-Jell MCP pectin, with the one difference that says, "MCP is available on the west coast." 
• Okay? I live on the west coast, and the regular Sure-Jell is available alongside the MCP, so why do our stores carry both? Any who... So here's the one I liked:

• I made jam successfully, following these steps, with strawberries, raspberries, and blackberries. I imagine you could combine and do a mixed berry with the same success. I am also going to try it with peach in the fall and will try to make a note if peaches worked the same.