If I start a 1 quart yeast starter using Wyeast 1056 (100 Billion cells), how many cells can I expect to gain? I use BeerSmith2 and it tells me I need a starter plus 1 pack for 237 Billion cells. I’m assuming it means that I need to create a yeast starter in addition to another yeast pack. Since each yeast pack is 100 Billion cells I guess my gain from the starter is 37 Billion cells? Am I understanding this correctly? BS also says if I don’t use a starter then I would need 3 yeast packs. Is there a way to know how many cells I’m really gaining from a yeast starter?
There is a great yeast resource online published by Jamil Zainasheff.
http://www.mrmalty.com/calc/calc.html
You can play around there with starter size and expected growth. My general procedure for a yeast starter of an average gravity 5 gallon batch would be at least 2 liters of approx 1.035 wort for one package of yeast. My understanding is that you don’t really get much growth with a one liter starter.
I was reading the book Yeast just the other day, and they have a chart with different inoculation rates to show that starter growth is dependent on starter volume and yeast cells pitched (not just one or the other). A quart starter, which is roughly 1 liter, with 100 billion cells pitched will grow by roughly 50%, resulting in about 150 billion yeast cells.
The MrMalty calc is definitely a handy tool to use, too.
Not without a cytometer, no. But Kai’s done some experiments recently for different inoculation rates and oxygenation techniques and found that the variation isn’t all that large. Roughly speaking, every liter of 10°P starter wort will grow about 100 billion cells using a stir plate, and about half that without one.
http://braukaiser.com/blog/blog/2012/10/08/yeast-growth-experiments-some-early-results/
Thanks for all the replies…I’ll check out the site as well. I am using a stir plate and my primary is like a volcano so I must be getting good cell counts.