How cold to crash a lager starter?

[Rob2010SS]

This weekend, I brewed 15 gallons of a mexican lager. I was using Omega OYL 113 which has an optimum ferm temp of 50-55*F.

My plan for a starter was a 2L starter, crashed and decanted, and stepped up to a 5L starter, which would then be crashed and decanted. Everything seemed to go OK. I crashed and decanted the 2L, boiled up 5L of starter wort and added the yeast from the first step to it. The 5L ran for 18 hours on the stir plate. I then placed it in my kegerator at ~38*F and crashed it for 22 hours or so.

Here's my problem - when I pulled the starter out of the kegerator in order to decant, the damn thing was fermenting away in my kegerator! Had a krausen and most of the yeast was still in suspension.

~38*F should have been cold enough to drop the yeast, no? Or do you need to get it colder than that to drop a lager yeast out of suspension?

 

[Robert65]

It isn't going to stop and drop until it's done fermenting. Apparently 18 hours wasn't enough.

 

[hottpeper13]

Threat it as a vitality starter and pitch the whole thing, since it did it's thing cold maybe it won't be too oxidized.

 

[Vale71]

You can only stop a yeast from doing with thing with changes in temperature if you either boil (not quite, but almost) or freeze the whole thing. Everything else is just wishful thinking.

 

[Rob2010SS]

So then, my next question is, why did it work with the 2 liter starter and not the 5 liter? The 2 liter crashed just fine and I followed the same process. Maybe it just fermented quicker than the 5L...?

I hardly ever make lagers. Actually, this is my 2nd one. My first one I just used multiple packs of dry yeast so I didn't have to do a stepped starter. I've read in other posts that people don't let their stepped starters ferment out completely, that they crash it after 12-18 hours. How do you guys do your stepped starters? You let each step ferment out completely?

 

[Vale71]

So then, my next question is, why did it work with the 2 liter starter and not the 5 liter? The 2 liter crashed just fine and I followed the same process. Maybe it just fermented quicker than the 5L...?

Exactly.

I hardly ever make lagers. Actually, this is my 2nd one. My first one I just used multiple packs of dry yeast so I didn't have to do a stepped starter. I've read in other posts that people don't let their stepped starters ferment out completely, that they crash it after 12-18 hours.

Some people like to believe all sorts of stuff. Yeast is impervious to our beliefs, unfortunately.

I'll let you in on a little secret: I run my ale starters at ambient temperature till I pitch them. The yeast will floc out just fine but you can help it along by adding quite a lot of calcium which won't affect the beer quality since you're going to decant it anyway. Personally, I do my starters with RO water and add 200 mg/l of calcium as CaCl2.

 

[Rob2010SS]

Exactly.

Some people like to believe all sorts of stuff. Yeast is impervious to our beliefs, unfortunately.

I'll let you in on a little secret: I run my ale starters at ambient temperature till I pitch them. The yeast will floc out just fine but you can help it along by adding quite a lot of calcium which won't affect the beer quality since you're going to decant it anyway. Personally, I do my starters with RO water and add 200 mg/l of calcium as CaCl2.

Thanks for the tip! I"ll definitely try that out on my next one.

 

[Beermeister32]

Check the OG of the starter. It sounds like the starter wort might too much fermentable material. A starter should be about 1.020 to 1.030 max.

 

[Rob2010SS]

OG of the starter was 1.037 which is around what all the calculators say they should be. Granted, the calculators could be off and I am not an expert on yeast by any means.

 

[VikeMan]

OG of the starter was 1.037 which is around what all the calculators say they should be. Granted, the calculators could be off and I am not an expert on yeast by any means.

1.037 is fine.

 

[Brewbuzzard]

This weekend, I brewed 15 gallons of a mexican lager. I was using Omega OYL 113 which has an optimum ferm temp of 50-55*F.

My plan for a starter was a 2L starter, crashed and decanted, and stepped up to a 5L starter, which would then be crashed and decanted. Everything seemed to go OK. I crashed and decanted the 2L, boiled up 5L of starter wort and added the yeast from the first step to it. The 5L ran for 18 hours on the stir plate. I then placed it in my kegerator at ~38*F and crashed it for 22 hours or so.

Here's my problem - when I pulled the starter out of the kegerator in order to decant, the damn thing was fermenting away in my kegerator! Had a krausen and most of the yeast was still in suspension.

~38*F should have been cold enough to drop the yeast, no? Or do you need to get it colder than that to drop a lager yeast out of suspension?

IMO you should never crash your starter, this is shocking the yeast and you want them happy and healthy. Let each step finish and settle then decant. It is also best to have the starter at the pitching temp. I use weak starters OG 1.030 to 1.040. They finish fast and don't stress the yeast.

 

[Rob2010SS]

Yep, agree with almost everything you said. I stay away from 1.040 in my starters, or try to. I always bring the starter to pitching temp as well. If it was in the fridge, I bring it out 3-4 hours ahead of pitching and decant to let it warm up.

The only thing that I disagree on, only because a lot of people do it and I don't believe it has a negative effect as I've never noticed it, is the crashing. I always crash my starters and decant off the old beer. Now, if I were taking a starter that was in the fridge at 38*F, decanting it, and pitching it into 65*F degree wort WITHOUT warming up, ok, then I agree. That's shocking them and not good for yeast health. But chilling, decanting, and bringing temperature up gradually, IMO, isn't a bad thing.

 

[TheMadKing]

https://www.whitelabs.com/sites/default/files/Flocculation_help.pdf
I'm just going to leave this here

 

[Brewbuzzard]

https://www.whitelabs.com/sites/default/files/Flocculation_help.pdf
I'm just going to leave this here

A good read. Thanks

 

[beerisyummy]

I too have only 4-5 lagers under my belt. But after reading a bunch o things, I've come around to this process.

1. I propagate lager yeast at room temperature. Someone somewhere said, "you are growing yeast, not making beer."
2. I make a step starter as an efficient way of having enough yeast without resorting to several liters of starter.
3. I wait for step 1 (1 L) to finish and then let rest 12-24 hours (because glycogen reserves and stuff).
4. I do NOT cold-crash step 1, because I don't want to stress the yeast by chilling, warming for step 2, and then chilling again. Folly, I say, folly!
5. I also do not decant step 1, so as not to lose any of the less flocculent, more attenuative beastie beasties.
6. Then I go to step 2 (2 L) and repeat, but this time after it ferments out I DO cold-crash the flask (at the same time the wort is cooling in the converted chest freezer), but just down to Ferm temp (around 50°F). So starter and wort will be same temp.
7. Since I didn't decant step 1 now I have 3L of starter. Way too much to just throw into 5 gallons of beer, so this time I do decant, and then pitch.

If anyone thinks I am "doing it wrong," please opine.

 

[Beermeister32]

Excellent explanation. Only difference I do is to drop the pitching temperature a couple degrees lower than the fermenting temperature (say pitch at 48F, ferment at 50F.) Bring the starter down to temperature in the same refrigerator or fermentation chamber as your carboy so they are the same temperature. Then let the inoculated wort in the carboy free rise to the fermenting temperature (50F). The majority of the starter yeast will have flocculated, so decanting the starter beer is easy and you'll have enough room in the carboy.

 

[beerisyummy]

Excellent explanation. Only difference I do is to drop the pitching temperature a couple degrees lower than the fermenting temperature (say pitch at 48F, ferment at 50F.) Bring the starter down to temperature in the same refrigerator or fermentation chamber as your carboy so they are the same temperature. Then let the inoculated wort in the carboy free rise to the fermenting temperature (50F). The majority of the starter yeast will have flocculated, so decanting the starter beer is easy and you'll have enough room in the carboy.

I like it!