Is my yeast impotent

[mattrickl06]

Just made 27l of Grolsch clone - i used Wyeast 2007 Pilsen Lager yeast which was made at the begiinning of April (3.5 months old)

I smacked it as usual around 4 hours before putting into the wort - stored it in the airing cupboard (22 degrees) but it didnt seem to swell, certainly not as much as every other pack i have used.

anyway it has been in the wort (OG 1055) for almost 48 hours and is not doing anything.

So the question is, is the yeast dead and should i pitch some more, and what should i pitch (i only have ale or hefeweizen yeast to hand)

 

[Asalpaws]

They say that the smack packs are OK for about 6 months. I've found lager yeast take a bit longer to get going than ale yeast, what temp is the FV? T

 

[MacKiwi]

Yeah, my lagers do take a while to get started. I wouldn't panic just yet...

 

[mattrickl06]

Temp is 22 degrees - will then be 9 degrees once I see some fermentation going on :shock:

 

[PD]

All yeast is important............................ :grin: :grin:

 

[anthonyUK]

For lagers, Wyeast recommend you grow a starter or at least use two packs.
1 pack is 50% underpitched for a standard batch so for 27l will be more hence the lag period could be even longer than usual.

 

[mattrickl06]

All yeast is important............................ :grin: :grin:

I need to do a lager largering process for my larger.

 

[mattrickl06]

For lagers, Wyeast recommend you grow a starter or at least use two packs.
1 pack is 50% underpitched for a standard batch so for 27l will be more hence the lag period could be even longer than usual.

Yeah that is what i was thinking - will have to be a starter in future i reckon cos i aint spending £13.40 just on yeast :wha:

 

[brewtim]

If it was manufactured in April then it will be at approx 25% of original 100 billion cells = 25 billion cells, so if you were doing a normal ale, you would need 200 billion cells requiring a stepped starter to bring it up to 200 billion. For lager you probably need to pitch more, requiring a bigger starter.

The yeast is probably working very slowly, it maybe stressed though, so pitch more yeast ASAP.

EDIT: From the yeast book it looks like a starter of 337 billion cells is required for a 19L batch of Lager. And confirmed by Mr Malty....http://www.mrmalty.com/calc/calc.html

 

[Good Ed]

+1 for what brewtim says, you need to pitch a big starter for lagers ~400bn cells. I take ~100bn cells (a standard WLP vial) step this up with 2L and 200g DME then step this up with 4.5L and 450g DME in a demi john, and then this is what I pitch.

 

[mattrickl06]

Do you pitch the starter trub only or the whole 4.5 litres??

 

[Good Ed]

Do you pitch the starter trub only or the whole 4.5 litres??

When the fermentation in your starter has finished, put it somewhere cool for a day or in the fridge and you then decant off the spent wort and you're left with the yeast to either step up again or pitch in your brew. You discard the spent wort as you don't want to add this to your brew, as it probably tastes ****. When pitching on brewday decant off the spent wort from your starter and add say 500ml of cooled wort from half way through your boil, this gets the yeast lively for pitching.

 

[mattrickl06]

Do you pitch the starter trub only or the whole 4.5 litres??

When the fermentation in your starter has finished, put it somewhere cool for a day or in the fridge and you then decant off the spent wort and you're left with the yeast to either step up again or pitch in your brew. You discard the spent wort as you don't want to add this to your brew, as it probably tastes ****. When pitching on brewday decant off the spent wort from your starter and add say 500ml of cooled wort from half way through your boil, this gets the yeast lively for pitching.

Many thanks for your help.

BTW the lager is fermenting nicely now

 

[brewtim]

BTW the lager is fermenting nicely now

How did it get going? :wha:

 

[mattrickl06]

Just took a bit longer (48 hours)