Originally Posted by BassetBrewingCo
When do you need a Yeast Starter
Typically, when you're using liquid yeast.
Most dry yeast packs have both a high cell count, as well as nutrients that would be lost if pitched into a starter.
That said, some people get by, by pitching two vials or smack-packs (depending on the lab) - though that doubles your yeast cost and doesn't necessarily guarantee you the correct pitch rate for your brew.