Jam is made from fruit that has been mashed, then simmered with sugar. It can be either thick or runny depending on how much sugar you use and whether you add pectin.
A good rule of thumb is to use fruit that’s not overly ripe. Overripe fruits lose their natural pectin.
Ingredients
Jam is made from pieces of fruit, usually chopped or crushed and cooked with sugar until the pectin releases and the mixture thickens. It is ideal for spreading onto toast and filling pastries.
To make your own jam, choose high-quality raw fruits that are ripe and still firm. Wash them thoroughly and then cut or crush them to use in the recipe.
Combine your fruits, sugar and lemon juice in a non-reactive heavy-bottomed saucepan. Stir and cook until the sugar is completely dissolved.
If the jam seems to be cooking too quickly, lower the heat and simmer for a few minutes. Be careful not to scorch the mixture over medium-high heat, as it can easily burn or boil over.
Preparation
Jam making is a process of boiling fruit together with sweeteners such as sugar, dextrose, invert sugar or liquid glucose to a suitable concentration. It can be made from one single fruit or a combination of fruits.
It is best to make small batches, as the fruit cooks quickly and the color and flavor are preserved. Also, it is important to follow the recipe exactly, because doubling or reducing the amount of sugar can interfere with the jam setting.
After cooking the mixture, you need to test it to ensure that it has set properly. Then you can ladle it into clean jars and store it in a cool place for up to 1 month in the refrigerator or up to one year in the freezer.
Cooking
Jam is a delicious, sweet treat that’s a simple combination of fruit and sugar. When boiled with a little acid, the sugar and fruit release pectin that thickens to a spreadable consistency.
High-pectin fruits, such as apples, berries and apricots, naturally thicken when cooked with sugar. However, low-pectin fruit like peaches and apricots sometimes need added pectin to thicken.
Cooking your jam on a heavy-bottomed saucepan with high sides helps prevent boiling over while allowing evaporation to help the jam gel. It also allows for the addition of a small amount of lemon juice to help balance the natural sugar/acid balance.
Testing
When making jams, jellies or marmalades the main thing that determines whether they set is the pectin content. Different fruits contain different amounts of pectin and it also varies according to the season and the ripeness of the fruit.
When boiling jams and jelly you need to ensure that you are cooking them long enough for the setting point to be reached. This is often a tricky task as the temperature of the jam changes dramatically as it boils.
You can try a few different ways of testing to see if the jam has reached its setting point. One way is the frozen plate test, this simply involves spooning a little of the jam onto a chilled plate and pushing it against the surface with your finger. If the surface wrinkles you have reached your set point.
