stepping up a starter

[Brycey]

I know how to make a 1l starter but i'm not sure on how to step this up to a 4l starter for my bohemian pilsner that i'll be brewing in a couple of weeks.

Can anyone help walk me through the process?

Cheers
B

 

[morethanworts]

Let the 1L ferment right out, then chill it for a few days to get all the yeast to clear down. Allow to rise back to pitching temp on the same day as making 4L of 1.040 wort from DME and chill it to pitching temp. Decant all but the last bit of 'beer' from the 1L starter, swish well, and mix with the 4L in whatever you're going to put it in. Ferment right out, chill down, bring back up to temp on brewday; once your boil is on, decant, restart with a bit of cooled wort from early in the boil, finish your brew, pitch. I hop I haven't missed anything too critical there...

 

[Brycey]

Cheers mate

Since i'll be fermenting the pilsner at around 10oc should i do the starters at this temp as well?

Cheers
B

 

[morethanworts]

Cheers mate

Since i'll be fermenting the pilsner at around 10oc should i do the starters at this temp as well?

Cheers
B

I don't think so. The job is to produce healthy yeast in quantity, not to produce the desirable clean beer that 10C will produce in the final beer. However, I will defer to someone with experience of lager starters.

 

[rpt]

You are growing yeast not making beer so you do not need to do it at lager temperatures. The Yeast book recommends 22C as striking a good balance of health and efficient propagation of both lager and ale yeasts.

 

[calumscott]

Cheers mate

Since i'll be fermenting the pilsner at around 10oc should i do the starters at this temp as well?

Cheers
B

Hmmmm. I'd be tempted, if you have the time, to build your starter at fermentation temp, that way you have trained yeast that will be the best they can in your ten degree wort.

 

[rpt]

I'd be tempted, if you have the time, to build your starter at fermentation temp, that way you have trained yeast that will be the best they can in your ten degree wort.

How will the yeast learn? Maybe over many generations natural selection will do this but not in the time it takes to make a starter. As I said above, the advice is to do it around 22C for ale and lager yeasts.

 

[calumscott]

How many generations in a starter? Stressing yeast is one of the big contributors to off flavours isn't it? So surely best if fermenting at 10, to grow the starter at 10?

 

[rpt]

I'm going by the Yeast book p137. Low temperatures will mean very slow and limited growth so you won't manage to grow enough yeast. High temperatures are bad but 22C is not high. Off flavours are not an issue as you are discarding the fermented wort. Even if you pitch the whole starter it is a small proportion of the total beer brewed.

 

[morethanworts]

I'm going by the Yeast book p137. Low temperatures will mean very slow and limited growth so you won't manage to grow enough yeast. High temperatures are bad but 22C is not high. Off flavours are not an issue as you are discarding the fermented wort. Even if you pitch the whole starter it is a small proportion of the total beer brewed.

Having checked my copy of Yeast, yes. And page 137 confirms that this is true for both lager and ale strains. However, just over the page on 138 it states that if your starter volume is greater than 5% of the main batch, you should definitely decant first... Not pitch the whole thing.

 

[rpt]

If it's 4L of starter for a 23L brew then, yes, you should definitely decant before pitching. But this doesn't affect the advice on temperature.