I posted this about a year ago, bringing over here to share as well for easy access...
How to Make Strawberry Jam
...at least how I do it!
Ingredients are 9 cups of hulled, clean strawberries, 4 cups of sugar, and 1/3 cup of lemon juice.
I start by well, picking my berries! These are all from my garden:
I like to just dump a batch into a bowl, fill with water, and rub the dirt off. If you don't get all crazy, the dirt settles to the bottom, and the berries all float. I just cut the top off with a knife. I put them in a colander on the other side. I also check for bad spots and cut those out.
After I cut them all up (do the whole batch that is in the water at once, so they don't get waterlogged - if you have to leave them, take them out of the water!), I measure out 9 cups and put them in my big ol' pot. I got it for about $5 at the dollar store - it's just a cheap steel pot. It's awesome. You want a BIG pot, and you'll see why later....
Take a potato masher and just mash the heck out of them, depending on how big of strawberry "chunks" you want. They will break down more. If you want perfectly smooth jam, then measure your whole berries, then run them through the food processor. I like some chunks. Put them on medium heat and let them come to a simmer. Add the sugar and lemon juice. I can't remember if I've added the sugar and lemon juice here, but you can see the texture kind of...
I don't use pectin or anything, so now is the fun part, the boiling. Bring it up to a full boil, and just stir regularly, every couple minutes. This is after a few, maybe 5 minutes:
And now it's REALLY boiling. THIS is why you want a tall, big pot. They are boiling at 2-3 times the "height" of just the berries. I still have lots of room to spare.
This is probably 15 minutes of boiling, at the same heat. Notice how there is some red showing, it's not just pink juice boiling like mad:
This is something like 20-30 minutes (I don't really keep track). This is where you want to stir it regularly. I have JUST taken it off the heat, but it pretty much looks like boiling, thick goo, and the foam is just on the sides. If you stick a spoon in and drip it onto a cool plate and hold it vertical, the drops of jam will slide and then stop. I like to test again by pushing a line through the jam on the plate with my finger. If it doesn't move, it's done
Skim off the foam - you don't have to get all crazy, I just use a wide, shallow ladle, and tap it onto a plate with paper towel, and wipe the ladle until all the foam is gone.
I don't have skills to show putting the jam in, but I just have a cheap plastic funnel that you can get in the canning section of the store, and fill my clean jars by setting the funnel on the top, and then ladling the jam in with a clean ladle. I always clean more than enough jars - having not enough is NOT FUN. You want to put your jam in ASAP - while it's HOT - so that when you water bath it, you know it's getting up to a hot, good temp.
Wipe the tops of the jar with a clean paper towel, put the clean lids on, and put the rings on just snug, and put them in the water canner! Fill with water til it's well over the lids (I go for about an inch). Hint - fill with the hottest tap water you can get out of your faucet ) Bring to a boil - enough that there are bubbles coming up and steam. Then put the cover on it, and set a timer for 15 minutes. When the 15 is up, carefully remove the lid, and use tongs to lift the jars out. Place them on the counter on a towel. I like to then carefully, with a towel over the top, snug the lid down again. You don't have to get all crazy, just hand tight. The heat and cooling will seal against the lid. You should hear them "pop" when cooling. After they are completely cool (I wait all night), check by pressing the lid. If it pushes down and springs back, you have to reprocess, or just put in the fridge and eat within a couple weeks. If it doesn't move and is all the way down, then it's good to store for a long time, at least a year. I like to check them every few months to make sure the lids are still down. If they pop back up down the road, then just get rid of it, don't eat it.
Jam!
Also, do not try to double canning recipes that require it to "set" like jams or jellies. It won't work. Do batches (thats why I have extra strawberries in one picture).
I personally don't use pectin because, well, I never remember to get it, and two, I prefer the SUPER taste - the boiling reduces the berries down and their natural pectin makes the jam - so you end up with a "concentrated" fabulous strawberry taste. It's amazing - like NOTHING you can get in the store. It also helps that I'm using ripe, just picked berries as they have a whole lot of flavor. Using pectin is faster as you don't have to boil nearly as long, but then you end up with not quite as concentrated flavor. There isn't anything wrong with pectin, I just prefer to take a few minutes longer and get that stronger flavor. There is also the pain of pectin when it doesn't decide to set for whatever reason, and you end up having to reprocess your jam (did this my first year with blackberry jam).
Enjoy!