I guess I really know lil about yeast. I always added a pack of yeast per 5 gallons, then I read that you really only need .75 pack of yeast per 5 gallons, and if you use a yeast starter, you can get by with half pack, so I started the yeast starter, and one pack of yeast for two 5 gallon carboys. Now I am in a delima. I heard in the last few weeks, of primary for 3 or more weeks to 2 weeks primary and 2 week secondary, and was thinking about checking out the dif. I am not sure I want to take a chance on it, no problem two 5 gallon carboys with a one pack yeast starter, but is a half of pack of 05 yeast enough for a 5 gallon batch of beer? I am short on 05 yeast tomorrow, so any suggestions, has anyone tried it before?
See my post in your other thread.
It depends on the original gravity of the beer, but in general I think you need more than 1/2 pack per 5 gal. Also, making a starter with dry yeast isn’t necessary and could be detrimental.
I would suggest using the starter to make one 5 gallon batch and then collecting the slurry to use on a second batch after you rack the first batch. Otherwise, get more yeast. I agree with Denny that you don’t need to make a starter with dry yeast - the yeast is packaged in a way that rehydrating it builds its cell walls before they try to absorb nutrient. Doing a starter may impair the cell wall strength or kill some of the yeast by premature absorption of nutrient.
I may not be saying that technically correct from a biology perspective, but it is not recommended to use dry yeast to make a starter. I do reuse it, however, and it seems that a few generations in the yeast gets pretty good. I never push the dry yeast past 5 generations, though, because I fear infection, mutation, bud scarring and nutrient deficiencies (but I will use Wyeast nutrient in later batches, to be assured of nutrient sufficiency).
