Should I use this starter or not?

[J2W2]

Hi,

This is kind of a continuation of my Wyeast 1007 post.

I made my starter yesterday, based on what I thought was a correct volume, which was 1.4 liters of wort. I pitched the yeast and put the flask on my stir plate around 5:00pm yesterday. There wasn't any activity yet by 11:00pm. This morning there was some light foam on top and a fair amount of bubbles coming up the side. By 3:00pm today there are still some bubbles coming up, but it has really dropped off. I have attached a picture of what it looked like today at the height of action (I don't know what it may have done overnight). Right now it just has a little ring of foam around the edge and the entire center is clear of foam.

I was printing out my recipe in Beer Smith 2 a little while ago, and realized the brew date showed August 1, which was probably when I started working on the recipe. I changed it to September 18, when I plan to brew, and happened to flip over to the starter page, and saw that it had used August 1st to calculate my starter. Using yesterday's date, my yeast viability drops to 24.85% (instead of the 36% it used) and it said I should use 1.08 liters of wort and two packages of yeast with a stir plate.

I went to the Brewer's Friend website, which I used before I got the Beer Smith 2 software, and their Yeast Pitch Rate and Starter Calculator page says my yeast is 167 days old (based on the March 30 2015 date on it) and the viability is zero. Obviously some of the cells survived, based on the fact I'm seeing some activity in the starter.

This is the oldest yeast I've used, but typically most of my starters get going the same day and usually show a pretty good krausen as well. This kind of makes me mad as I bought the yeast at our local home brew store. I'd like to give him more business, but his prices are considerably higher than what I can get online. I bought my yeast from him this time as I didn't want to risk having it shipped when it's this warm out. I should add that the pack was already swollen when I got it, so I have no idea when that occurred.

The way I see it I have three options.

1) Go with what I have and hope I'm pitching enough yeast. I really don't like that option as I don't even have a clue how many cells I might have.

2) I could put the starter in the fridge for a day or two, and then create a second starter with it. Again, the main problem is I won't have any real idea how many cells I'll be pitching.

3) Go back to the store tomorrow and get another packet, if he has any newer Wyeast 1007. Or possibly a White Labs WL029.

This is my first attempt at a homemade recipe, so I want to control everything I can in case I want to tweak it later. Not having a known pitch rate is not going to help that out.

Having written all this, I think I've talked myself into getting more yeast and doing another starter, but I'd still appreciate any advice you may have.

Thanks!

 

[chickypad]

Mrmalty puts the viability at 10%, yeastcalc at 25%. Even if you use the low end of that at 10-15% you've about 75-100 billion cells, or similar to a new pack. I'd decant and pitch what you have into a new starter - you clearly have viable yeast. I've used pretty old yeast stepping up like this before and it works pretty well at least going by the size of the yeast cakes that I get. You do have to guess a bit as far as which calculator to trust but I don't let it worry me as long as I see the expected fermentation.

 

[iijakii]

Personally I wouldn't worry much about it. You can't judge much off of krausen. Sometimes they just don't foam up much at all, especially on a stirplate and knocking it back into the liquid. If it's fermented out well then I'd feel fine using it, but stepping it up into a second starter would be the safe way to go for sure.

 

[J2W2]

Mrmalty puts the viability at 10%, yeastcalc at 25%. Even if you use the low end of that at 10-15% you've about 75-100 billion cells, or similar to a new pack. I'd decant and pitch what you have into a new starter - you clearly have viable yeast. I've used pretty old yeast stepping up like this before and it works pretty well at least going by the size of the yeast cakes that I get. You do have to guess a bit as far as which calculator to trust but I don't let it worry me as long as I see the expected fermentation.

The Brewer's Friend starter calculator uses two methods, Chris White and Braukaiser. Both have a stir plate option, but they have very different results. Based on Braukaiser, I should have my 200B cells even at 10% viability on the yeast packet. By White's calculation, I probably have somewhere around 80-108B cells.

So, I'm either at my desired pitch rate, or only half way there. It's been on the stir plate for 25 hours now, so I guess I can refrigerate and see how big a yeast cake I get.

Playing with the calculator, it looks like a small second starter, 0.75 liter or so, will get me about where I want to be if I have around 80-100B right now, and would only kick me up to 245B if I'm already at 200B. This is all based on Braukaiser's calculations. I'm guessing this may be the better choice since it should get me to, or a little over, my target pitch rate?

Thanks again for your help!

 

[chickypad]

Actually yes I see the 200B now too, I usually use Kai's calculations but I think I had it set wrong. I'd crash it and see what you get, may be able to just roll with that (realizing that eyeballing the yeast cake is less than accurate but I do it anyway).