"Sarge" > wrote in message
...
>
> "J F" > wrote in message
> ...
> >
> > "Sarge" > wrote in message
> > news
> > > I encountered an H2S problem when I made wine from chardonnay grapes
> that
> > > were sprayed with sulfur. The sulfur residue could be seen on the
> grapes.
> > > Of course the H2S may have been caused by some other reason and the
> > problem
> > > was resolved by aeration.
> > >
> > > I wonder how a spray program of sulfur and copper could affect
> winemaking.
> > > Does residual amounts of sulfur on grapes contribute to free SO2 and
H2S
> > in
> > > wine?
> > It can contribute to H2S in your wine but most vineyards stop spraying
> > sulphur weeks before harvest for this reason.
> >
>
> In a bad season they may have to spray closer to harvest. Also what if it
> doesn't rain after the last spray, would some sulfur still be on the
grapes
> at harvest?
>
It's possible the sulphur levels could be high enough to cause troubles in
such a situtation. In such cases it's advisable to watch your nitrogen
levels and even be a bit heavy handed with nutrients.
If you get your grapes unpressed and whole cluster, gently washing them with
clean water can removed the residue. You'll need to let them drip dry before
pressing.