"michael" wrote in message
...
Thanks for that very clear piece of advice.I probably will continue to
wash the grapes,ferment on natural yeast and add sulphite after the
fermentation has finished,just as you describe.I tend not to bottle
but rack the wine into 1 gallon demijohns-at this point I intend to
sulphite.One final point.When you say add 15-20ppm of free SO2,is that
very approximately 0.5 Campden tablet/gallon or 0.1g of metabisulphite/
gallon?I am a little confused after reading all the science about
molecular SO2,free SO2,total SO2,bound SO2.
Thanks again
Michael

Another alternative. Buy a bottle of Campden tablets and follow
the instructions on the bottle (eg. 1 tablet per gallon). Problem
solved......... )