I have some Kilner clip top jars and am now making jam for the first time. I would like to keep the jam for at least 6 months unopened so I found out I need to vacuum the jars after I have put the hot jam in.
It seems the screw lid jars are quite easy to vacuum: just turn them around on their head and let them cool. However, Kilner's site suggest I need to water bath the clip top jars for 30 minutes in order to vacuum. See here: http://www.kilnerjar.co.uk/making-you...
It says: "If you are using a Kilner® Clip Top Jar, place the rubber seals onto the top of the jar and close the clips. Place the jar in a large pan and cover the whole jar with water. Bring to the boil for 30 minutes."
I'm just worried what that will do with my jam: won't it make the jam mushy and lose its fresh flavours?
Next time I'll go buy the screw lid jars, but for now: what is the best way to vacuum?