Capacity of Kilner jars

[OldGreyBeard]

Hi,
I have a selection of Kilner jars found in my parents garage. These are pretty old as I remember them as beng old in the 1960s. Anyway the KilnerMan bloke has been helpful in identifying the correct size of sealing ring but I am still left pluzzling over the capacity.

Vintage jars seem to be sized in lbs but what actual volume is each weight and weight of what in any case?

My jars seem to be a mixture of 700mL and 1L capacity when filled to the neck but what does this mean in lbs?

[Thomzo]

Hi
Hmmm, yes It does rather depend on what you are putting in them. Very dense foods will be heavier than lighter foods. Given that most food is largely water, and 1 litre of water weighs approximately 1 kilo at normal temperatures, you can probably guess at the weights from the volume.

I suspect that the old jars were probably sized in the weight of preserved fruit that you could get into them but that then begs the question of whether it was the raw weight (as in go out and pick a pound of strawberries to preserve) or the cooked weight, but who would bother weighing the cooked food and then going out to buy the appropriate jar?

I agree, definitely odd. It would make far more sense to size them in volume.

Zoe

[Thomzo]

Wow, the ads work. I've just had an ad for the jam jar shop.

Sorry, guys go to go jam jar shopping. Bye

Zoe

[boboff]

For jam add about 10% for chutney it about par, but this is very ish.

so for Jam 1 Ltr would be 1.1kg to 1.2kg, obviously depending on how full the Jar is ( don't overfill you need a 4% min head space to get a decent vacuum)

[OldGreyBeard]

Well I did a more accurate measurement today and found that the smaller ones hold 800mL and the larger ones hold 1.1L

A standard 1lb jam jar seems to be 378mL which means that the 800mL jars work out at just over 2lb and the 1.1L at just over 3lb which would fit with the possible sizes available for the age of the jars.

They were found in a house we lived in the 1960s, when I was a child, and were old then so I reckon they must date from the war. The joy is they still work and I've used a couple today.

[Thomzo]

My mum once cleaned a house that had some very old kilner jars that dated from before the war. The only problem was that they had been full all that time. She wasn't very impressed when they kept exploding all over her newly cleaned floor.

Zoe

[OldGreyBeard]

I found a jar marked as a 1lb jar and it has a capacity of 14 fl oz or about 400mL