Understanding The Calculator
Dry Malt Extract (DME) is estimated at 43 gravity points. Liquid Malt Extract (LME) is estimated at 36 points.
Yeast starters are highly recommended when you have old yeast (at or past expiration date) or when you need to increase the cell count. Cell counts need to be increased when you are reusing slurry or are pitching into a high gravity wort (>1.050 OG). Yeast starters are not suggested when using dry yeast.
It is important to have the gravity of your starter within the range of 1.030-1.040 specific gravity (SG). Having a starter of this gravity will promote healthy yeast growth without introducing too much unneeded stress.
Yeast Cell Counts
This calculator does not tell you how much of a starter you will need. But as the starter's volume increases, so do the count of viable yeast cells. For instance, a 5-gallon batch of 1.064 ale wort would require about 227 billion viable yeast cells to ferment properly. The count of yeast cells will vary with the original yeast source, the wort's OG and the equipment used. For getting your pitch rate correct, we suggest using the BrewersFriend.com pitch calculator.