# us05, two packs?



## louistoo (5/2/16)

Hi Brewers, I'm just hydrating two full packs (22g) of yeast for my export stout. The og was 1063, volume 21l. The recipe was based on jamils export stout in byo, og 1071, vol. 19l.
He says to use 12g (1g more than one dry pack of us05 or I think nottingham, s04). Homebrew shop guy said one would be fine.
I ran it by brewersfriend calc. and it says I'm still like 20 billion cells or so short with the two packs.
So what do you guys think?


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## SBOB (5/2/16)

I would say 2 packs would be fine, and I likely wouldn't bother rehydrating but thats an entirely different question and can of worms


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## Vini2ton (5/2/16)

If I was using us-05 I'd probably use 1, rehydrated. But if I was using s04 I'd use 2, rehydrated. I made some stout with californian lager yeast which is yum. I reckon rehydrating dry yeast as per spec kicks it off faster.


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## louistoo (5/2/16)

I pitched the two hydrated packs already anyway, but can see the logic in one pack. Last time I pitched 2 (hydrated!) in a wort of similar gravity and had a massive amount of yeast at end of a very vigorous ferment. Made a nice beer though!

edit; confusing though the varying advice given, still thanks for your thoughts.


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## JDW81 (5/2/16)

SBOB said:


> I likely wouldn't bother rehydrating but thats an entirely different question and can of worms


I rehydrate and sometimes brew with pants on.

Go with two packs, rehydrate and brew pantsless, it's the only way.


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## Mr. No-Tip (5/2/16)

Two packets rehydrated was the way to go. Quicker start. Healthy ferment.


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## Chridech (5/2/16)

US-05 is a very clean yeast. I think there would be more problems with underpitching than over pitching. Many brewers have had no problems with pitching directly onto a massive US-05 yeast cake. 1g/l of US-05 is quoted as a common pitch rate for those who buy their US- 05 yeast in 500g blocks. Def would pitch 2 packs rehydrated for a 1063 wort when your aiming for a dry stout. 0.75 million cells/L/degree Plato is a standard pitch rate for an Ale. 1 million for a higher ABV, eg > 1075.

Haven't tried brewing pantless, but might give it a try.


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## Brewman_ (5/2/16)

2 packs.

If pants are off, be sure to sanitise thoroughly.


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## Blind Dog (6/2/16)

Personally I've found that rehydrating dried yeast and pitching sans clothing is the way to go. Not entirely sure if it's the rehydration as recommended by just about anyone who actually might know what they're talking about with degrees and stuff in relevant subjects, or the sans clothing, but my money's on the sans clothing. SWMBO is not convinced


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## nosco (6/2/16)

The only reason i like to rehydrate is because i aerate with a big pour from the cube or with a paint stirrer. If i use dry yeast it just sits on top of the wort foam and totally defeats the purpose of aerating. I could put the dry yeast into the fermenter first but then when do i take a OG sample? I dont want to have to think about things too much.


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## Chridech (7/2/16)

Blind Dog said:


> Personally I've found that rehydrating dried yeast and pitching sans clothing is the way to go. Not entirely sure if it's the rehydration as recommended by just about anyone who actually might know what they're talking about with degrees and stuff in relevant subjects, or the sans clothing, but my money's on the sans clothing. SWMBO is not convinced


After much Professorial introspection and consultation of the trub at the bottom of yesterday's brew, I have determined a pantless brewing yeast pitching rate correction factor.

The recommended pitch rate for an Ale = 0.75 millions cells/ ml wort/degree Plato - R(n-2)/2*(SWMBO)3

Where R = Rehydration coefficient. R =1 for rehydration, R = -1 for dry pitch
n = number of pant legs worn
SWMBO = a correction factor specific for the Brewer's domestic circumstances

That should do it!


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## Black Devil Dog (7/2/16)

2 packs rehydrated and brew with your pants on so that your donger doesn't dangle in the fermenter. Unless you've soaked it sanitiser first, then it's ok to brew pants off.


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## Lord Raja Goomba I (7/2/16)

Gotta sanitise the donger, so that when I stir in the rehydrated yeast (pantless of course), I don't give the beer any addition yeast varieties.


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## Danscraftbeer (7/2/16)

I'm horrified! Surely protective clothing is in order around burners and 50lt kettles and stuff. OH&S?
As for the pitching? I never thought of it that way.

Oh. 2 packs. Or! you could brew up a starter with 1 pack on stir plate for 6 or so hours. Just a little brew frigaround and save yu $7 bucks.
I check yeast calculations with as least 2 different source/calculators. Usually over pitch a little by calculations and then a few brews were slightly under pitched by calculations but they made a good beer but definitely a little different as in more flavors. Yeast count can be underestimated in the end product result I'm thinking, finding, maybe.....


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## louistoo (8/2/16)

Thank you all for the learned discourse


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## Lord Raja Goomba I (8/2/16)

Sorry, I'll give me serious advice. 

I made (and placed) with an IIPA with BRY96 (which is at least stylistically close to us05 ). I brewed a normal IPA with it, made wort for an IIPA and took krausen from the top of the former to inoculate the latter and it took off like a rocket. 

Given you're doing a stout, a little under ptich won't cause major dramas as won't an over pitch. I'd rehydrate two packs but I've brewed many 1.060 beers with one pack rehydrated and not had an ounce of an issue.


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## Blind Dog (8/2/16)

Ooops - sensible comments it is then

Without actually counting the cells it’s pretty much impossible to say accurately how many viable cells are in a packet of dry yeast (or a vial of liquid yeast) at the time it’s pitched. The viability is affected by age, handling, strain etc. A packet / vial that been shipped from the manufacturer in ideal conditions and kept properly will have a higher viable cell count than the same packet / vial shipped in a 30C heat and left sitting on a shelf until used. That said, for our purposes as home brewers, reasonable estimates are usually OK

The viability of US-05 is, per Fermentis >6bn cells per gram at packaging, and presumably declines from there. The issue is that >6bn just means more than 6bn without any indication of how much more. Brewer’s Friend defaults to an estimate of 10bn cells per gram for dried yeast (at pitching) and I think Mr Malty defaults to 20bn cells per gram. So brewer’s friend will give a 23bn cell deficit for 2 packs, but Mr Malty (which I understand Jamil Z was/is involved with) will tell you 2 packets is an overpitch.

IMO, you’ll be fine with 2 packs, so long as they are fresh and, as far as you can determine, well kept. If you’re worried, a small starter will get the yeast going so that you know it’s working when pitched into your wort


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## Matplat (8/2/16)

I have a similar issue, (and Bribie has pretty much answered it, but I still like having my hand held sometimes) Mangrove Jacks say to pitch two packs above 1.050 for 23l.

I was shooting for an OG of 1.046 (based on 75% eff) so I got one pack, but my pre-boil S.G hit 1.050! (which I think works out to 85%eff) which means my O.G will probably be more like 1.053 (won't know for sure until I put it in the FV), talk about over-shooting.

It'e very fresh yeast as they have only recently released the California Lager yeast, but I'm just wondering if I should make a starter? Do you even get yeast growth if you pitch a whole pack into 1l of wort?

I'm thinking it will be fine as is with one pack, but I wouldn't mind if someone agreed with me (or not!)?


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## MastersBrewery (8/2/16)

with twice as much yeast should air lock kittens be increased also????


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## Matplat (8/2/16)

Yeah you've gotta watch those fuckers


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## Goose (9/2/16)

Fermentis US-05 (dried) is a great yeast.

I gave up using liquid ale yeasts after trying this one hydrated and sprinkling atop wort.

2 packets for a 45 litre batch has never failed me.

Also, just my 2c, I have noticed no difference pitching dry (sprinkling atop the wort) vs rehydrating with this yeast.


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## welly2 (9/2/16)

Been using US-05 fairly regularly lately. Last batch was pitched dry and I found it took 24 hours or so for fermentation to kick off. I've found that to be the case most times I pitch fermentis yeasts. Last time I rehydrated the yeast into a black IPA, it kicked off pretty quickly. The next morning, there was a healthy krausen. 

Never pitched more than one packet at a time and I'm pretty slack in aerating my wort. Half the time I'm amazed I get beer at all with my shoddy practices. Certainly goes to show that give yeast an inch and they'll take a mile, the greedy feckers.

Got oodles of white labs yeast so will be all about that for the foreseeable future and I'm planning on dusting off the old stir plate in preparation. 

And I'm a pants on kinda guy. Must be my uptight British upbringing.


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## Tropico (9/2/16)

With this hot weather it is better to stay hydrated to begin with. This is much easier to achieve with pants off, and rehydration isn't a problem as long as you keep your fluids up. Some people achieve this with beer while others say it dehydrates you even more.

So, now that we have covered that, for those who sprinkle, do you just sprinkle, or sprinkle and stir?


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## Goose (9/2/16)

Tropico said:


> So, now that we have covered that, for those who sprinkle, do you just sprinkle, or sprinkle and stir?


neither actually. I just pour it in, and seal the fermenter.

is that bad ?


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## Tropico (9/2/16)

Goose said:


> neither actually. I just pour it in, and seal the fermenter.
> 
> is that bad ?


I wouldn't know. I can only think that just sprinkling and sealing would allow the yeast to hydrate, have nutrients available from the wort, and use the gaseous oxygen in the head-space before using the oxygen dissolved in the wort.

Maybe it is better to utilise dissolved oxygen first rather than gaseous oxygen in the head-space. Maybe it doesn't matter, just another can of worms.

Edit: It's only bad if it produces a fault in your beer.


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## [email protected] (9/2/16)

My normal yeast is US-05. I sometimes sprinkle and sometimes rehydrate it. I haven't really noticed a difference in the end beer. Usually I notice some activity in the first 12-18 hours regardless of how I pitch. 

My most recent brew started at 1.050 and I just sprinkled it. 24 hours in I had no action to speak of and was worried I'd made a big mistake. 26 hours in I had a few bubbles forming and at 28hours a creamy krausen. 72 hours post pitch I took a sample and was down to 1.022 already. Despite the slow start I have no reason to doubt this will work out just fine.


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