'lo Sabine,
SB> I'm looking for a possibility to make a cooked tea stay fresh
SB> for some days. I'm cooking fruit tea for stock, and after two
SB> days the most sorts smell muffy.
Unless you freeze it or pastuerize it somehow in a preserving jar I
should think that some kind of degeneration is going to occur. Given
that you are using fruit I would hazard a guess that what you have
got is a fermentation, so perhaps you could try your local home brew
shop for what I call 'stopping tablets'. They contain a chemical
(the name of which I forget) which prevents fermentation by blocking
an enzyme which yeasts use to breakdown sugars. You also have to add
Campden tablets otherwize the stopping tablets can impart a 'hot'
taste to the finished product.
They are pretty potent substances and for smallish volumes I think
you'd need to make up a solution of the two and add a proportion of
it, they folks at the homebrew shop will doubtless be able to help
you with this. 
Just a thought, hope it helps.....
Duncan
... "What ya doin'?" "Just feeding the pigeons."
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