OG = Original Gravity = Beginning Gravity.
With dry yeast starters are NOT recommended:
- Dry yeast comes with it's own nutrient stores ready for fermentation, and by making a starter, you use all that up before you pitch the yeast in the beer.
- Dry yeast packets also contain a lot more cells than liquid yeast, making a packet fine for most regular gravity beers.
- Dry yeast stores better than liquid. Providing it has been stored reasonably, you can be reasonably confident of the viability of the cells, whereas liquid yeast viability drops quickly by comparision and is more susceptible to poor storage conditions.