Testing Jam: is it set?

There are few things more frustrating than making jam only to find that it is runny and not set.  There are 3 methods recommended for testing the jellying point:

1.  Temperature: use a candy thermometer to measure the temperature of the jam.  The jam should be boiled until it reaches 104 degrees.

2. Spoon test: Dip a cool metal spoon into the boiling jelly mixture and lift the spoon out of the steam and turn the spoon on its side so the jam runs off the side. When the mixture first starts to boil, the drops will be light and runny.  As you keep boiling the mixture, the drops will become heavier and will drop off the spoon two at a time.  When the two drops form together and "sheet" off the spoon, the gel point has been reached.

3.  The plate test: put a few saucers in the freezer to cool them.  Put a teaspoon of jam on the cool plate and let it stand for 30 seconds.  Run your finger through the jam: if it crinkles the jam is cooked enough. If not, cook for longer and test again every 3 minutes.

The last method works well for small batches of jam but is not considered as reliable as the first 2 methods.  For beginners, we recommend using methods 1 and 2.

Usually, jam made with pectin will set if processed according to the instructions on the pectin packet.  Jams that do not use added pectin may not gel but can be rescued by returning the jam to the preserving pot and adding pectin according to the pectin instructions.

It is also possible to make home made pectin using either apples or citrus, if you make alot of jam.  I have also heard of people putting apple pips in a cheesecloth bag and putting this in with the jam while it is being boiled (the seeds being high in pectin but obviously an unwelcome addtion to the jam!).

Note that by using the water batj method to preserve jams you do not need to use plastic covers on jam such as the old fashioned Fowlers Vacola Kleerview covers.