Yeast & Starter Questions:

[Octang]

OK, so I'm spending all day today studying about yeast and so far I have learned a lot, but I am coming upon some unanswered questions you may be able to clear up for me:

1.) I have figured out how to calculate how many cells of yeast I need to pitch depending on what I am brewing. However, how do I determine how many cells I am actually pitching if I make a starter out of my washed yeast? (should I make a certain sized starter and let the yeast grow to the optimal population, or what?)

2) On the How to Make a Yeast Starter thread (How to make a yeast starter - Pictorial - Home Brew Forums) it says 2 cups of water and 1/2 cup of DME. So when making larger starters do I keep this same ratio as I increase amounts?

Everything that I read about yeast suggests it is just about the most important aspect of brewing beer as it relates to the flavor of the final product. Yet every kit I've purchased and just about every recipe I've read treats yeast as almost an afterthought... paying little attention to giving any direction to ensure you are pitching the proper amount of yeast. So it almost makes me wonder if I am putting too much thought into this. Either way, I want to learn more about yeast, so no knowledge is ever a waste of time.

As a preemptive edit: Before you mention that I should read: http://www.mrmalty.com/starter_faq.htm. I have read it a few times, and I plan on re-reading it a few more times.

 

[SavageSteve]

There is an excellent pitching rate calculator at Mr Malty which will tell you exactly how big of a starter to make to reach the proper cell count. Also, there are some excellent articles there about making yeast starters.

And no, you are not putting too much thought into yeast-- it's critical for good beer.

-Steve

 

[Octang]

Hey thanks.

I saw that calculator and noticed the different tabs for liquid, dry and slurry yeast. If I am using washed yeast that I pitch into a starter, would I use the calculation for starter size listed under Liquid yeast then (i guess my main confusion about that was whether that was just for purchased liquid vials or not)? Because that is the only place I see that shows a starter calculation.

Assuming I do use that calculation, how can I rest assured I am dumping the proper amount of washed yeast into the starter? I have washed three batches of yeast so far and they have given me varying amounts of sediment at the bottom of the jar. The latest one was very thick in sediment and I was worried I may pitch too much yeast into the starter. (or maybe at a future date, I may pitch too little washed yeast into the starter for optimal results)

 

[SavageSteve]

With washed yeast, you'd have to have some method for estimating how many total cells you have. Mr. Malty's calculator assumes 100 billion cells at the start, which is the average that a White Labs vial or Wyeast Activator pack have.

I've only run across this page (Wyeast Laboratories : Home Enthusiasts : Brewers : Technical Information : Pitch Rates) that talks about estimating cell count for washed yeast-- it's at the bottom.

-Steve