Wine is different than making beer. With wine, you'll have that first very
visible fermentation in your primary. If you have a hydrometer, you'll be
able to tell when your wine has fermented to dry - your reading will be 0 or
below (which can take 1-2 weeks depending on the yeast and the temperature).
But if you're like me, who likes a semi-sweet wine, and you want some sugar
left in the wine, then there's always a chance that one yeastie-beastie will
use that sugar to start things again. After the initial ferment is over, I
put my wine into a secondary for up to 7 months (racking as needed). I've
had wines, which I thought were done, restart again in the secondary, and
after bottling (popped corks and a mess). I now stabilize my wines. As
Roger pointed out, beer can be done in 2-3 weeks, but wine can take months
and then years to age, so oxidation is a greater concern when making wine.
Hope this helps.
Darlene

"Rich" > wrote in message
om...
> I have made a few batches of beer and want to try a wine. I'm a
> little confused about the procedure. It appear that it is recommeded
> to top off in the secondary, why? Is wine that much more sensitive to
> oxidation than beer? The few books I looked at all seem to guess when
> fermentatiopn is done, cannot you use a stable SG as a sign that it is
> done? Look forward to your insights.