Yeast starter question.

[MattGuk]

Hi all

I made a 4ltr starter on monday evening in the hope it would be ready for tonights brew which is a lager.
Today its a high krausen but am unsure if i should cool it now, so i can pitch tonight or if i should wait till friday till i brew.

Any advice would be hugely appreciated.

Cheers

 

[SpeedYellow]

Definitely wait! A 4L starter with no stir plate will take 2-3 days, then you'll need another 1-2 days to crash cool the starter so the yeast drops out and get cool. You don't want to pitch an entire 4L starter. And with lagers, you don't want to pitch room-temp yeast. So best plan is crash cool the starter for 1-3 days then pitch it directly from the fridge ( or let it gradually come up) into 46-50F wort. This works well. Pitching warm lager yeast does not, however.

 

[MattGuk]

Ok thanks fir the info.
i remember reading that there is a whole lot of different opinions regard this,
but that a lot a brewers like to pitch any starter, regardless of size at high krausen as that is when all the yeast is produced and is also ready to get at the job, plus doesnt lead to off flavours?
I wish the was just a definitive yes or no to every question lol

 

[SpeedYellow]

Well, there's nothing wrong with pitching at high krausen for an ale, but that doesn't work for lagers:

1) First, you really want to make sure you have enough yeast, and it's impossible to know your cell count if the starter is somewhere mid-way through fermenting.

2) Second, a lager starter is simply too big to pitch the entire thing!! I certainly hope you weren't planning on pitching an entire 4L starter! That's 20% of your batch size. Yuk. With lagers, you simply have to decant the liquid off of the yeast, thus you have to wait until the starter is completed.

3) And third, the lager yeast when pitched need to be as cool or cooler than your fermentation temp. So pitching your starter at krausen doesn't work unless you run your starter at 50F, which isn't what people do.

Yes, learning to do lagers well takes some patience, but it's worth it.

 

[MattGuk]

Thanks that clears things up a lot.
i will wait until the weekend before i brew.
krausen has started to fall now and more yeast is showing at the bottom.

Cheers