Pitching yeast, how much?

[Mike1981]

Hi guys, i started doing all grain lagers a few months back, on which Aleman kindly advised to pitch lots of yeast. I generaly throw 2 11.5g packets of dried yeast in each 23l brew. Do i need to do the same with beers using S-04 or will 1 packet be ok?
Michael

 

[keith1664]

1 packet is good.

 

[Mike1981]

cheers keith, is there no benefit from chucking 2 in?

 

[Stone Cold]

nope none really, yeast will multiply as it eats the sugar,

 

[Mike1981]

Cheers lads :thumb:

 

[Good Ed]

S-04 is an ale yeast, Fermentis do 3 lager yeasts S-23, S-34/70 and S-189. I would use 2 packets for a 23L brew length and rehydrate per the Fermentis recommendations http://www.fermentis.com/FO/60-Beer/60-21_product_rangeCB.asp. The benefit of using 2 packets is a shorter lag time at the lower lager fermenting temperature.

 

[Good Ed]

Sorry Michael, I misread your post , and agree with the other guys 1 pkt of S-04 will be good, I would rehydrate it though.

 

[snoopdong]

Sorry to hijack the thread, but how about going the opposite way to the OP.

A good yeast can represent a significant cost in an AG brew >10%, what about HALF a pasket for 23L?

(Also whats the best way to store an opened packet, air tight box?)

Regards,
Chris

 

[Aleman]

A good yeast can represent a significant cost in an AG brew >10%, what about HALF a pasket for 23L?

(Also whats the best way to store an opened packet, air tight box?)

If you really want to save money why don't you just pitch one cell of yeast? That one cell will reproduce enough given time, to ferment your entire batch . . . just think how many brews you would get from your one sachet of yeast then. . . . . Of course you have to offset the savings against the number of ruined batches that you will get because you are too tight to pitch enough yeast in the first place!

The minimum pitching rate for ales of normal gravity is 1 million cells per ml of wort. An 11.5g sachet of yeast, properly rehydrated, will provide 20 billion cells . . . which in a 23L batch is approximately 1 million cells per ml.

Don't skimp on yeast they provide 60-80% of the flavour components of the beer . . .get it wrong and get poor quality beer

 

[keith1664]

Sorry to hijack the thread, but how about going the opposite way to the OP.

A good yeast can represent a significant cost in an AG brew >10%, what about HALF a pasket for 23L?

(Also whats the best way to store an opened packet, air tight box?)

Regards,
Chris

or pitch the whole packet then harvest the yeast, or is that too sensible?

 

[snoopdong]

Don't skimp on yeast they provide 60-80% of the flavour components of the beer . . .get it wrong and get poor quality beer

Point taken, I hadn't realised that yeast contributed so greatly to taste, better safe than sorry I guess.

But for the sake of argument, with care, i.e. taking off a half pint of boiled wort at the start of the boil into a sterile bottle to give the yeast a head start, one should be confident of the yeast still doing its bit? Not knowing the speed of yeast growth what % increase in cells would you see over say 2 hours (i.e. 90 min boil, + 30min cooling to pitch temp)? Would it be up to the same level as if I just pitched the dry yeast into the full length of cooled wort?

or pitch the whole packet then harvest the yeast, or is that too sensible?

That probably is sensible. How do I do this? I think I read about taking yeast from the foam in the primary FV and collecting the cells on kitchen towel, before freezing... Is this right?

Does yeast deteriorate in subsequent generations? I.e. if the process was repeated time and time again would the, say 5th generation perform different to the first?

Sorry for all the questions, just learning! :thumb:

Regards,
Chris

 

[keith1664]

I'm no expert, I've been harvesting yeast for the last 2 months and it's not difficult. Google yeast washing on how to do it.
I'm not sure you need to get so anal on the sterilising either, I've managed 3 generations so far without resorting to autoclaves, a good soak in Starsan has worked fine so far.
Apparently you're good for five generations, in my slightly tipsy maths thats 63 batches...not bad value.

 

[snoopdong]

I'm no expert, I've been harvesting yeast for the last 2 months and it's not difficult. Google yeast washing on how to do it.
I'm not sure you need to get so anal on the sterilising either, I've managed 3 generations so far without resorting to autoclaves, a good soak in Starsan has worked fine so far.
Apparently you're good for five generations, in my slightly tipsy maths thats 63 batches...not bad value.

Thanks I will do some investigating! :)

 

[Aleman]

There are some breweries like the Saltaire Brewery that are on the 800th odd generation.

 

[Aleman]

Don't skimp on yeast they provide 60-80% of the flavour components of the beer . . .get it wrong and get poor quality beer

Point taken, I hadn't realised that yeast contributed so greatly to taste, better safe than sorry I guess.

But for the sake of argument, with care, i.e. taking off a half pint of boiled wort at the start of the boil into a sterile bottle to give the yeast a head start, one should be confident of the yeast still doing its bit? Not knowing the speed of yeast growth what % increase in cells would you see over say 2 hours (i.e. 90 min boil, + 30min cooling to pitch temp)? Would it be up to the same level as if I just pitched the dry yeast into the full length of cooled wort?

Not a hope, you pitch 10 billion yeast cells into . . .a pint or two of starter wort . . .first off the viability will be reduced compared to properly rehydrating it . . . and you have pitched enough yeast to ferment 10+L of wort . . .the yeast will wake up, use up its trehalose energy reserve, and then the majority will stop as there is insufficient sugar for them to reproduce. While you may "get away with it" (and many do ) it is no substitute for pitching the correct amount of yeast. Many funky flavours, poor fermentations, and cloudy beer can simply be attributed to pitching insufficient, healthy, yeast. It is not for nothing that the Thornbridge brewery pitches 7-8 million cells per ml . . . which is 7 or 8 times the minimum pitching rate. . . . Why/How do commercial brewers get fermentations complete in three days? Pitch enough healthy yeast . . . Shimples

or pitch the whole packet then harvest the yeast, or is that too sensible?

That probably is sensible. How do I do this? I think I read about taking yeast from the foam in the primary FV and collecting the cells on kitchen towel, before freezing... Is this right?

Does yeast deteriorate in subsequent generations? I.e. if the process was repeated time and time again would the, say 5th generation perform different to the first?

There is a good basic "How To" harvest yeast for repitching written by Jim (Evanvine) in the "How To" subforum . . . I'd do it differently, but I have more equipment available to me to make other methods preferable.

 

[Stone Cold]

There are some breweries like the Saltaire Brewery that are on the 800th odd generation.

thats amazing! thats very good beer as-well, brewing is obviously full of myths and opinions isnt it, many times i have been told it cant be done after 10-15