Starter pitching temperature

[Etnabrews]

I made a wort with OG of 1.077, a Lager, I made a starter the day before using s-23 and kept in my refrigerator so that it would be at optimal lager temperature. I realize a one day starter is not ideal but based on time constraints I went for a 1 day starter as opposed to multiple day or dry yeast. I cooled my wort to low 70s before pitching the starter, which was still showing excellent activity, also shook many many times the first afternoon and during the next day while I was mashing etc.

after pitching I put the beer in my bulkhead (which keeps beers at perfect lager range) and left for three days. I came home and the beer was showing no movement in the airlock, not swirling of yeasties, and no kraussen. My assistant brewer was checking daily and said there was never any movement.
There were lots of what appeared to be floating clumps of yeast on top. Not knowing what to do I pitched
a dry packet of 34/70 because I happened to have in the fridge. the beer is fermenting now but what happend to my starter? temperature shock? would it just die like that? I have never had yeast die even when I pitched too hot.

 

[WoodlandBrew]

Can you tell us more about the starter? What was the OG the volume? Was the yeast new, or from a slurry and how much yeast?
What was the volume of wort this was pitches into?
Just to make sure I understand you correctly are you saying that the starter was in the refrigerator for most of the propagation time except for when you were shaking it?

My guess is that you had very little cell growth and under pitched so there was very little activity.

 

[fixitoscar]

So your starter came out of the fridge and went directly into 70's wort? If so going from 42ish to 70ish instantly is not the best thing for your yeast.
You should be pitching at the low end of your fermentation temp. If that is not an option, you should at least have your starter fairly close to the temp your wort is at when you pitch.

 

[WoodlandBrew]

Good point it's much better to pitch a little cooler than fermentation temperature than with wort above fermentation temperature. The drop will send the cells into dormancy.

 

[Etnabrews]

Well to answer your first questions: The starter was a pint of water with 1/2c DME and 1 package of dry s-23 (this only the second starter I have ever made, the first worked very nicely) and put in the fridge, which I did because it was a lager yeast wouldn't it do just fine in there?

Even if I under pitched wouldn't 3-4 days be enough time for the yeast to slurp up all the 02 and begin fermentation?

It seems that yes indeed my starter was simply shocked by going from cold to warm.

 

[Etnabrews]

Oh also what does pitching at low end of fermentation range do for you exactly? do you then want to raise the temperature a little after?

 

[fixitoscar]

being in the fridge isn't bad. its the rapid temperature jump that is going to shock and kill your yeast. If you are going to pitch at 70 then pull the yeast out of the fridge and let the temp rise naturally to 70 then pitch. For a lager you want to pitch cold. If you pitch hot then cool everything down you tend to put a lot of your yeast asleep.
Pitching on the low end allows you to slowly ramp up your temps and drive the yeast to finish up the best they can. Keeping them active for as long as you can. Generally keeping temps down for the first 48 hrs keeps a lot of off flavors away.

 

[WoodlandBrew]

Well to answer your first questions: The starter was a pint of water with 1/2c DME and 1 package of dry s-23 (this only the second starter I have ever made, the first worked very nicely) and put in the fridge, which I did because it was a lager yeast wouldn't it do just fine in there?

It might have gotten going eventually in the refrigerator, but even for a lager yeast you'll want to "start" it at ambient. The goal is to propagate yeast at this point, not make beer. At ambient temperatures it takes 6-12 hours for cell division to begin. In the fridge it could take quite a while. It's likely that there was very little cell division in your starter. The hydration of the yeast is crucial with dry yeast. If you mix it in right away to the wort or water the viability will be very low.

see here:
http://woodlandbrew.blogspot.com/2013/01/how-many-cells-are-in-package.html
(I have a more detailed post coming up soon)

Even if I under pitched wouldn't 3-4 days be enough time for the yeast to slurp up all the 02 and begin fermentation?

Not with a lager, and especially if it is under pitched. (What was your batch size?)

It seems that yes indeed my starter was simply shocked by going from cold to warm.

Cold to warm would cause shock excretion, but doesn't slow down the yeast a whole lot. Warm to cold causes the yeast to prepare for dormancy. Your yeast went cold to warm (when it was pitched) and then back to cold (as the beer dropped down to the temperature of your bulkhead).

 

[Etnabrews]

Gotcha, thanks much, will take into account next time I make a lager starter/ferment a lager.

 

[Etnabrews]

Woodlandbrew: On your last two points: Would the yeast have eventually started to ferment the beer even if under pitched and if (based on the last point) it didn't "slow down the yeast a whole lot"? If it underwent shock excretion does that mean the yeast prepared itself for a warmer environment by excreting waste? and then as the temperature dropped it had to reverse that function and resume its cold behavior? thus stressing the yeast and massively reducing the number of cells?

 

[WoodlandBrew]

Yes, it likely would have started eventually. It takes a lot to kill yeast. When yeast are "stressed" they don't die very quickly. What they do is spend their energy adapting to the environment instead of dividing or fermenting.