Cold crashed starter still going strong in fridge?

[Brewsit]

I made a 3.5L starter of WLP001 (California Ale) that I started Friday night and let run on a stir plate until about 24 hours later. It was very vigorous and the first time it blew the foam stopper out, I went ahead and popped it in the fridge to cold crash. About 20 hours later, I am noticing that the krausen still has not dropped, and it continues to release big CO2 bubbles from the bottom. What on earth is going on? It hasn't cleared up very much, and just keeps bubbling. Normally I wait until the krausen naturally drops most of the way to crash, but I didn't want to wake up to a giant pool of yeast on the counter, so I crashed a little early. Is this normal, and am I going to just have to wait longer for it to stop bubbling and drop out of suspension?

 

[raouliii]

I always cold crash after the starter finishes fermenting.

 

[Brewsit]

Me too. Looking for the opposite.

 

[IL1kebeer]

3.5L is kind of big for 1 vial, especially if the vial wasn't close to being at maximum viability. Do some research on starter inoculation rates and you might find out why it acted the way that it did. Ideal inoculation rates make sure your starter does what it's intended to do: propagate yeast. Too low of an inoculation rate and you are really just making beer (although 3.5L probably isn't quite at that level yet). Different inoculation rates should have an effect on the yeast's behavior in the fermentation. Not sure if this is exactly why your starter is continuing to ferment longer but I think that it may play a role.

 

[Brewsit]

Viability was still high considering it was produced about a month ago, and I usually do starters that size with one vial. Only thing that changed was the time. I know other people out there have crashed at high krausen, curious to see if they see the same thing or if mine is a freak of nature.

 

[Brewsit]

I checked it again 48 hours after it being in the fridge and was still producing enough gas bubbles that on one side a constant stream was coming from the bottom. I decided to just decant a good portion of the liquid and mix it up, which released enough gas that it shot the foam stopper out the top.

 

[Oskar]

I'm having a similar problem as we speak. There is a mason jar covered with foil in my fridge with 400ml of Belgian Strong (Wyeast 1388) starter active for 48h now. There was definitely a kraussen continuing for the first 12-24h after putting it on cold, and now I see just some foam at the top. But inside the jar, the wort is definitely not clear.

I was hoping to decant at least 3/4 of wort before stepping up to 1,5l. But if I do it now I'm afraid of loosing a lot of yeast. So, I can see another 24h of waiting.

 

[kh54s10]

I don't have an explanation for the fermentation. But you are pitching about three times the yeast needed by making a 3.5 liter starter. Unless it is something like a barley wine that you are brewing. At the least you are paying for a lot more DME than you need to.


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