Problems with aerated starter

Hi guys! New poster, long time reader here.

I've been looking for help for a long time now on Homebrewtalk, but still haven't found exactly what I'm looking for. So if you like challenges, give this post a shot!

So, here's the problem: When I grow a starter from wyeast / white labs lager strains, I get a HUGE lag time from fermentation (like 3 days) and my fermentation won't start unless I bring it up to about 64F (18C) for one day, and then I can bring it down. I am sure I am pitching enough yeast cause I use a Neubauer chamber to count on a microscope, using pitching rate of 1.5 million cells / mL / Br.

The starter conditions are:
-10 Brix wort with nutrients pressure cooked.
-Aeration of 1 lpm of oxigen per liter of wort
-Temperature on the 77F-86F range (25C-30C)
-24h growth time (after that the yeast count won't go up)

Any help AT ALL will be appreciated. Cheers guys!

 

Im not quite sure what you mean but I presume that you feel that the beer (not the starter) has lag time.

It is normal for fermentation at low temperature is calm. Sometimes so much that it seems that it has not even started even though it has. I would bet that if you pitch a good starter and take a gravity sample after 3 days you would see a drop from OG even though it seems quiet.

That does not mean that you should/could not raise the temperature after a while. When and after how long is up to you. Some will suggest after 50% of fermentation, some when there are a few points left to FG.

 

Sounds like a solid process to me. Agreed, raise the temp as gravity falls.
Though if you are eager to hurry along the process: Build the starter at a lower temp (as to not cause shock) & pitch the yeast at its most active reproduction (earlier than 24hr).
Ive cut a german lager starter early and cold crashed in the fridge to flocculate + separate. Worked great. My wort temp fell too low, 50deg (keezer ferment) and the yeast had it back up 55deg in two days.

 

Awesome, that's what I wanted to know. Thanks!!

 

Just an aside, are you using a dissolved O2 meter to determine this? Im wondering if you aren't over oxygenating and killing yeast cells. Any reason you are not using a stir plate for gas exchange?

 

If you're pitching a warm starter into cold wort, that could be your problem. Thermally shocking the yeast. Either build your starter at ferm temp, or at least crash it down beforehand and then let your starter warm back up to just below ferm temp on brewday.

That said I don't stress 3 day lag on lagers.

 

Yes, I've used a DO probe when I worked at a lab that had one, and determined this was the optimum point.

I'm not sure you can kill yeast cells by over oxigenating it, though. And as a matter of fact, I tested for viability and was over 99.5% everytime.

I'm not using a stir plate because this way is more effective and I use a sterile filter to make sure air is free of bacteria.

 

Yeah, what I'm actually doing is I'm building it up at around 77F, storing it in the fridge, and on brewday I let it warm up to room temp before pitching. Maybe I should try growing it at a lower temp, even though it might take longer to grow, just to make sure.

I didn't quite get what you meant there. You mean that a 3 day lag on lager is usually OK?

 

I don't usually see visible activity on mine for 2-3 days, but if I check gravity it's definitely dropping.

I pitch harvested slurry from one that's lagering and warm it to my lager pitching temp (49F) before repitching.

Don't warm it to room temp if your wort is cold. I'd sooner leave it at fridge temp than room temp.

 

How much oxygen do you give the wort before pitching? If you give too much maybe they are busy growing if there is still oxygen available.


I use a stir plate for my starters and allow them to coast for 8 to 12hrs off of the plate before putting into the fridge. Supposedly helps build reserves.

I decant and pitched into the prechilled wort without allowing them to warm up. It is only about a 10 degree difference between the fridge and the chilled wort and they are going from cold to warmer which should wake them up. If you allow it to warm to room temp(assuming 70s) then pitch into cold wort that could trigger them to go back to sleep.

Some strains seem to start off slower then other but I usually have active fermentation within 24 hours of pitching and slow ones in 36hrs.