me and my jam again!

[crisgal]

I've started my jam, but have no jars! (I was sure I had some) I do have some brand new tupperware pots - will they do? Are they airtight? x

[Clanad]

The high sugar content of most preserves, jams and jellies will assure their "keeping" for some time, but if the type of jam you are preserving is low sugar then the Tupperware will not suffice. The low sugar content preserves required a water bath of at least 35 minutes or, in some cases, pressure treating. The metal lids are especially designed for this function and the plastic storage devices are not so designed. If you kept it refrigerated in the Tupperware, it would porbably keep for some time, but you still run the risk of microorganism growth...

[crisgal]

how long would it keep in the fridge, in a tupperware, clanard?