"Ben Rotter" > wrote in message
om...
.."Tim O'Connor" > wrote:
.. > To me this is an important issue because I am constantly topping up
barrels
..> so I need to keep the sulfites up (for the periods between top ups). So
.. > what do others do? New sulfite every six months and keep good notes or
rely
.. > on titret measurements?

..Keeping good notes and frequent sulphiting isn't enough because you
..need to accurately account for SO2 binding. You really need a
..measurement of the free SO2 to be able to do this (since every wine is
..different in its binding potential). Titrets are tricky, but with some
..value adjustments and/or reference measurements you can get consistent
..results of an accuracy that is sufficient for general practise. For
..more, see sections 14.3-14.5 at:

.. http://members.tripod.com/~BRotter/SO2.htm

..Ben

Thanks for the suggestions. I like the hydrogen peroxide idea, just to get
an idea of how much the iodine is reacting with other compounds (phenols).
I have measured musts that should read 0 (or close to) and have been
surprised how high they were.
Tim
PS-nice article.