Any way of telling if I have under pitched yeast?

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HowbeckAles

HowbeckAles

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How do!

First all-grain lager is underway in the brew fridge. I used a Wyeast Pilsner liquid yeast that didn't swell as expected when I activated the packet but chucked it in nonetheless. Nervously ordered another packet just in case and a week on there is a good krausen developing and a decent amount of yeast in the fermenter from the original packet.

Is it worth chucking my new packet of Wyeast into the mix anyway? It's just sitting in the fridge and might not get used for a while. I'm not sure if I have under-pitched or not. Can it hurt to throw in more yeast a week in to the fermentation?

Cheers all.
 
How many litres are you brewing? One liquid pack is not really enough for five gallons of lager.

It's probably too late for more yeast to make a difference I think. Take a hydrometer reading.
 
It worked out a shade under 20L once it went into the fermenter. I'm away for a few days now so I'll take a gravity reading when I get home. Will have been nearly 2 weeks by then I think.

Is there a chance of a stuck fermentation then?
 
There's always a chance! But the chances are greatly reduced by pitching enough healthy yeast. And good aeration of the wort. I wouldnt worry though, beer is remarkably resilient, it wants to happen, and yeast wants to eat sugar and multiply. We often get away with murder when we make beer. Do you have temperature control for your fermentation?

I'm wary of people pitching liquid yeast packs into 20+ litres of beer. The amount of live yeast cells in a pack is not reliable. And lagers need twice as much yeast as ales. Dry yeast is a good option until you get your head round yeast handling. Two 11/12g packs in 20-23 litres of lager.

Take a hydrometer reading when you're back and post it on here.
 
Noted! I thought liquid yeast would be more "reliable" than dry yeast plus it gave me a chance to throw my hat into the ring and try something new.

I recently built a temperature controlled brew fridge which is holding up well and doing the job nicely so I'm confident that the temperature side will give the yeast the best chance it has of making my beer. Set it to 20 degrees I think which seems to be slightly above the mid-range temperature for the yeast.
 
You're right, that is too warm. It's the Wyeast 2007. As I said I'm away now but I set it to the warmer end of the temperature for the yeast so I guess it must be around the 13 Celsius mark. I think I pitched it at 20 because I couldn't cool it down enough so it went into the fridge at 20 and cooled down from there.
 
HowbeckAles said:
You're right, that is too warm. It's the Wyeast 2007. As I said I'm away now but I set it to the warmer end of the temperature for the yeast so I guess it must be around the 13 Celsius mark. I think I pitched it at 20 because I couldn't cool it down enough so it went into the fridge at 20 and cooled down from there.
Click to expand...


That sounds ok. If the pack you got was in good condition things could work out fine. And some additional yeast may help if it's only partially fermented when you get back.
 

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