Making Berry Jam

When the berries are plump and plentiful in the markets and farmstands, make berry jam.

By Family Tme


If you've never made jams and preserves, you'll be surprised at how easy it is. If it's been awhile, why not make some before the summer ends?

Now is the time for raspberry and blueberry jam. The berries are ripe and sweet and because they are in season, they are more reasonably priced than usual.

Safety First
As easy and safe as jam making is, never take shortcuts and always follow a reliable recipe.

Berries and other fruits are high-acid foods, which are far less prone to spoiling than low-acid foods. Plus, the sugar added to them contributes to their safety and earned these treats the name "preserves." There is no difference between a jam and preserve. What you call them is up to you.

Certain recipes may call for lemon juice, which simply ups the acid content.

Some folks like to process these in a water bath, but the open-kettle method, described here, is equally effective.

Jam-Making Supplies
You don't need fancy equipment. You will need a heavy pot, sterilized jam jars and lids, a wooden spoon, and some thick pot holders. A jelly or candy thermometer is useful.

The pot is the most important. To prevent the berries from burning, it should have a heavy bottom and good heft. If you have nothing but a thin aluminum pot, set it on a flame tamer to avoid scorching.

The pot should be large enough to hold about four times the volume of the ingredients.

Buy jam jars at supermarkets and farmers markets. These generally are smaller than other canning jars with a quilted pattern etched into the glass. They come with screw-on lids.

Topping the jam with paraffin is not necessary, although some jam makers like it. Melt the paraffin in the top of a double boiler over hot water and then spoon a thin layer on top of the jam. Prick any air bubbles and then let the paraffin set before screwing on the lid.

Sterilizing the Jars
To sterilize the jars, wash them in warm, soapy water, rinse well, and then put them in a large pot. Pour boiling water over them and then return the water to a full boil over high heat. Boil for 10 minutes, turn off the heat, and leave the jars in the hot water.

Lift the jars from the pot with jar tongs when you are ready to fill them.

Jam-Making Techniques
Start with fresh, clean berries. Rinse them under cool water and drain. Use only premium berries; discard any that are unripe or show signs of rot or mold.

If the recipe calls for added pectin, which is necessary for jelling some fruit, buy it at the supermarket. As a rule, berry jams do not require pectin.

Put the berries in the pot and crush them with a fork or spoon. Add the sugar and pectin, if called for, and cook over medium-high heat, stirring with a wooden spoon every now and then until bubbling. Raspberries will soften and melt; blueberries will soften and pop.

Let the mixture cook until it's the consistency you like and the correct temperature. You might prefer a smoother jam to a more textured one.

Spoon the hot jam into the jars and leave about a half inch of headroom. Screw the lids on the jars or top with paraffin. Set the jars on a thick kitchen towel to cool. Don't let them touch each other but leave enough room for air to circulate.

Label the jars and store them in a cool, dark place. Unopened, the jam will keep for up to a year. Open when you are ready to use and store opened jam in the refrigerator.