Jam Jars

Jam jars can be bought specifically for home preserving or you can re-use jars you bought containing commercially produced jam. You can use jars again and again so, once you have a box of them, they should last you for years.

Jars that used to contain shop bought jam have two considerable advantages: they are effectively free since they were the throw away packaging for the jam you bought, and they have screw on lids that provide an air tight seal. If you choose to buy jars specifically for home preserving you will pay more of course, but have a greater choice over size, shape and type of lid.

However you source your jars, collect a sufficient number of them before you make the jam, as it wont keep well left in an open container.

Jars should be checked for chipping, cracks, damaged lids and the *right* lids (its all too easy to get the wrong lid when so mny jars are just a little bit different ), and any unfit jars desposed of so you don't get them muddled up with the good ones again.

Prior to use, the jars should be cleaned,or given a rinse in hotwater if they have been stored for a while. They should then be warmed and sterilised. The easiest way to do this is to place the jars (without lids on) in a cold oven, switch on and set it to about 140 to 160 degrees C. Once it reaches the right temperature, switch off the oven and allow the jars to stay in there until they are used, still hot to the touch. If jars are cold when you pour jam into them, there is a risk that they will crack.

Once filled with jam, the jars need to be sealed quickly so the cooling jam will create a slight vacuum in the jar and prevent it going off in storage.