Cool Thanks :)MKG wrote:Acid - very possibly. It serves three purposes. One is the final taste - if there's not enough acid, the wine can taste insipid. Another is the yeast - it likes an acidic environment, so the fermentation may be sluggish if there's not enough acid around. The third is the danger of infection - much less likely if the acid levels are correct. But no worries - you can add the acid now.
The wine doesn't usually stay around that long to age :)MKG wrote: Tannin serves two purposes. It gives the wine a bit of "bite" - all wines should have at least a little bit of tannin. Secondly, it helps with maturation - a low-tannin wine will not age particularly well. Again, though, you can stick it in now.
Thanks for the pointers!