When Can I Add Tannin?

[vbkid]

So I'm just wondering at which stages I can add tannin, and what the benefits might be at each stage? Does it affect yeast growth or anything of that nature?
Thanks,
Kyle

 

[Yooper]

Tannin adds "bite" to wines. Usually a tiny bit is all that is needed. I start with about 1/8 teaspoon or so, add it by dissolving it in some of the wine and gently add it back to the entire batch, and then wait about 12 hours and taste. It's easy to overdo it.