OK, wild blackberry jam. I want to make some, I crave the taste of homemade wild blackberry jam. It's a "free for the picking", fruit. There are a lot of reasons I could give you why I want wild blackberry jam, but mostly it's because it is so darned good.
Wild Blackberries are smaller than domestic blackberries but it's thought that they are a lot more flavorful. I would agree with that however domestic blackberries also have smaller seeds so 6 of one and half dozen of the other.
Wild Blackberries can be found in our area in the foothills growing out of control so much so that people are constantly cutting them back, digging them up and even trying to use chemicals to control them. They can also be found in the San Joaquin river delta growing wild along the sides of the levees where picking them can be challenging if the tide is not out creating a small beach area to walk along.
We like to go to the river to do a little fishing then berry picking when the tide goes out far enough to access the berries. Sometimes we take one or more of the grand kids and sometimes we go alone. Either way we make a day of it with a picnic lunch and lots of iced tea. The day gets pretty hot in July when they ripen. They start ripening the end of July and continue through August so you have several chances to pick them.
It takes about 5 cups of berries and 7 cups of sugar to make one batch of jam. You also have to add a box of pectin to make it set up (thicken). I normally make two batches at a time and will get about 10-12 pints of jam. Some of the berries I crush and use the juice to make some syrup for pancakes.
The fruit and the box of pectin goes into a large kettle, then brought to a boil that cannot be stirred down. The sugar is added and it's brought back to a boil again and timed for 2 minutes then removed from the heat and poured into jars. You can add 1/2 teaspoon of butter or margarine to each batch to prevent foaming from occurring. The foam won't hurt the jam but it does look prettier without it. It can be skimmed off before putting in the jars however.
The hot fruit and sugar mixture is carefully ladled into hot, clean, sterile jars. I usually keep the jars hot after washing them by putting them in a roaster pan and in the oven on 200F until I am ready to use them. I remove them one at a time with a pair of tongs then using a food funnel I ladle in the fruit and wipe off the edges of the jar so there is no food between the flats and the glass jar. Put on a NEW flat lid and a ring. The rings should only be hand tight not over tight.
Process in a boiling water bath by putting the jars in the hot boiling water, waiting for the water to come to a boil again and putting the lid on the pot. Once the water has come to a complete boil again time it for 10 minutes then remove from heat. Take the jars out and listen for them to "pop". It makes a pinging sound which tells you the jar is sealed.
Blackberry syrup is made similarly. Equal parts of blackberry juice to sugar. This will make a thinner syrup similar to real maple syrup however if you like your syrup thick you can add about 2 tablespoons or no more than half a package of pectin. Bring it to a full rolling boil then time it for 2 minutes. Remove it from heat and fill your jars using the same method as the jam. Process it in a boiling water bath for 10 minutes and remove from heat. Don't forget to wait for the "ping"!
Some fruits need some lemon juice to properly set up, the best way to know which fruit need lemon juice and which fruits don't is to buy a canning book or to buy a package of pectin and read the instructions.