US-05...Is One Packet Enough?

[beersk]

Eh, I still use the shake method in 6.5 gallon carboys.  Might as well aerate at least somewhat with dry yeast, eh?

[bluesman]

@beersk

Might as well aerate at least somewhat with dry yeast, eh?

Yes. I always aerate the wort whether I’m using liquid or dry. They need the O2 to go to battle. 

[morticaixavier]

@brewqwest

Ok, I am a bit confused here… Back on page 1 of this thread, The quotation by clayton cone states that each gram of the dried yeast contains 20 billion live yeast cells.  But on their own web site they quote different quantities. See here for the spec sheet on their Nottingham yeast: http://www.danstaryeast.com/sites/default/files/nottingham_datasheet.pdf
Item 2 states they have more than 5 Billion cells (5 x 10⁹ =5 billion right) per gram but
Item 4 of that pdf file states 100 grams in 100 hectoliters gives you a density of only 5 - 10 million cells per milliliter. This could be equivalently scaled to 10 grams at 10 liters or only 2.64 gallons. Which would mean I would need 20 grams for 5 gallons just to give me a max of 10 million cells per milliliter. Furthermore, if you look up SafeAles S-05 pdf sheet, you will find only 6 billiion yeast cells per gram. Meaning a 11 gram sachet would only have a maximum of 66 billion yeast cells!! Or am I computing wrongly here… ??? Is not 6 x 10⁹ not equal to 6 billion??

A hectoliter is 100 liters. so 100 hectoliters = 10,000 liters so that’s .01 grams per liter or .1 gram per 10 liters or 1 gram per 100 liters to hit that 5-10 million cells per milliliter.

[brewqwest]

@morticaixavier

A hectoliter is 100 liters. so 100 hectoliters = 10,000 liters so that’s .01 grams per liter or .1 gram per 10 liters or 1 gram per 100 liters to hit that 5-10 million cells per milliliter.

thanks for correcting my math… I originally figured 10 grams to 10 liters which I see now was way off… but does the correct answer of only 1 gram to 1 hectoliter (100 liters) giving 5-10 million cells per milliliter seem wierd to anybody else??? cheers!!

[a10t2]

@brewqwest

but does the correct answer of only 1 gram to 1 hectoliter (100 liters) giving 5-10 million cells per milliliter seem wierd to anybody else??? cheers!!

That must be a mistake. I think they meant to say 100 g per 100 L, or 100 g per hL, but instead wrote both.

[gimmeales]

Just piling on my experience for another data point - I’ve got clean, full fermentations with 1.070 wort with one packet of US-05 (rehydrated per instructions).

This went against my better judgement at the time, but it was all I had and was going to hit it with another packet if it stalled on me, but it didn’t.  Made a very nice Robust Porter