[Milly]

I bought what I consider to be 'medium' sized kilner jars today, half price in sainsbury's. They are the kind that have a screw on lid with a detatchable inner circle with a rubber rim.

I have Vals book that reccomends sterilizing on a baking sheet in a very low oven with the lids beside them for 10 mins but just to clarify -
Would you consider a low over at 50 degrees?
What about the inner part of the lid with the rubber? Will it melt?

[hamstergbert]

many people recommend 80 C for jar sterilising.  Personally I put them in cold and heat it up to 120 then let the oven cool back down to just under the ton before filling them - increases confidence in killing off the nasties and  also reduces thermal shock by flattening the temp difference with teh jam.

I have put the rings in too without obvious deterioration but generally chicken out these days and chuck them into a large plastic jug and cover them with boiling water.  The fun comes trying to fit them into place while still hot without dropping them, blistering me fingers or using more than three swearwords per jar!

[Yorkie]

It's just as much fun trying to stretch them over the neck of a glass jar with metal spring clips round the same neck, when the metal is hot too!

Only 3 swear words, that's quite an achievement 

[hamstergbert]

Only 3 swear words, that's quite an achievement 

per jar!

[Yorkie]

Good point 

[Endymion]

I wash and rinse jars then put them upside down on a baking sheet in a hot oven, that I turn down to the lowest setting once they're in. I only turn them up the right way when they're going to be filled.

I scald sealing rings and any separate lids, then put then on the bottom of the top oven/grill so they dry out and stay warm but don't stay hot long enough to melt or distort.

Pulling the rings onto the lids can be a bit of a challenge, but I hold the jar and lid with a dry tea towel and hope my fingers don't get too close to the metal bits.

[Lindeggs]

If I'm using just a few jars I put them in my big stock pot full of boiling water and boil them (jars and lids). 

A friend recently sterilised his jars in the oven and made them too hot - they imploded when he put his marmalade in them!   Apparently jam is about 120 degrees Celcius when it's boiling so the jar should be around 100 - 120 degrees.