# Us05 And Diacetyl



## goomboogo (5/7/08)

In a recent thread a couple posters mentioned recent experiences with US05 and diacetyl. I have used this yeast quite a bit have never had such a problem. Until now. The fementation was carried out at 17c ( I usually get it around the 17c-18c mark). 2 weeks in the keg and there is an absolute truckload of butter. I don't usually perform any sort of diacetyl rest with this yeast, fermenting at a similar temperature for the same amount of time and have never had the problem. Has anyone else had a similar experience with this yeast and are there any theories for what appears to be a change in the diacetyl production of US05?


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## matti (5/7/08)

Diacetyl has a shit load to do with yeast growth or lack of.

In your case 
1. The sachet may have been a bad one.
2.The wort low in oxygen or yeast nutrients
3.It is slighty infected with a lactobacillus
4. all of the above.

if its is infected it will go sour soon enough.
First sign of this kind of infection is usually cloudiness.

US05 or US56 is a great yeast and like yourself I generally brew this cool. 16 degrees or there about.

Best way to make this one to ferment out, is to aerate the wort at beginning and ensure you raise the temperature to about 20 degrees after 7-8 day.
Usually 10 days in primary rack and chill.


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## Maxt (7/7/08)

I have a fresh 100gm pack of US05, and man, does it throw diacteyl. Even when I have fermented beers at 17-18 I still have had a problem. I am currently 'recovering' a dry Irish stout that is the latest victim.
Yes, I fully aerate my wort, and I doubt that most people would have fresher yeast than I have.

This experience is mirrored by lots I have spoken to lately. I only ever used to have this problem when doing faux lagers at 15degreees. Perhaps having temp control now means that the temps are not creeping up beyond what I though I was brewing at....

My conclusion is that I need to do a d rest at 20-21 degrees for every US05 beer from now on.

I love this yeast, but it certainly needs some attention.


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## Jerry (7/7/08)

Maxt said:


> My conclusion is that I need to do a d rest at 20-21 degrees for every US05 beer from now on.



Find I need to do the same thing.

Scott


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## Hutch (7/7/08)

Slightly on topic...
About 6 months ago I pitched 2 packs US-05 into a simple AG aussie pale, and boy did it throw some acetaldehyde (green apples). Left it sit in a keg for a few months of wishful thinking, and it didn't get any better - ended up chucking it.

That dampened my opinion of the yeast, and since then I've also noticed quite a few case-swap using US-05 showing similar acetaldehyde characteristics. I know a lot of brewers swear by the stuff, though in my limited experience there is a noticable quality difference between it and 1056.
Maybe Fermentis have changed the strain in the last year or so, perhaps coinciding with the name-change from US-56? Just guessing...


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## sah (7/7/08)

18 - 19C all the way. No diacetyl. Dry and clean.


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## Millet Man (7/7/08)

I did 4 test batches recently with US-05 at 18-20C (4 sachets bought at same time) and all of them reeked of diacetyl. After about a month in the keg it has faded (all 4 kegs) but is still there in the background. Never had diacetyl from this yeast before.

I initially suspected an infection but the beer is quite drinkable now and definitely not off, so maybe a batch problem with the yeast?

Cheers, Andrew.


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## bonj (7/7/08)

I have also noticed diacetyl in my beers, particularly at 16-17. I regularly do a rest now for US05, at around 21-22. Seems to clear it up. It has coincided with using "official" fermentis us05 packets (the reddy coloured ones) instead of the craftbrewer "American Ale" yeast. Not sure whether that means the official packets aren't as healthy, or what.


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## MVZOOM (7/7/08)

I use US05 a lot - had one Diacetyl'd beer about 12 months ago and one which didn't clear well about 3 kegs ago - but the rest have been pure, clean and stellar?

Cheers - Mike


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## Maxt (8/7/08)

I bought a 500gm sealed pack of the Fermentis us05. Many others I know have also noticed these effects. It's no drama to do a diacetyl rest though.


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## sinkas (31/10/11)

I pitched two rehydrated packs into a 1105 IIPA @16, and a day after its faoming crazily and and the whole shed stinks of diacetyl
wort was well O2'd and clean, I hopeign it will scrub out cos at the moment, its friggin stinky


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## kjparker (31/10/11)

I use us05 almost excusively, and have not had any problem with this. I typicaly leave my beers for three weeks in primary however @ 18deg. I am also using harvested yeast from previous brews yeast cake as well. Dont know if this makes a difference or not....


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## Nick JD (1/11/11)

sinkas said:


> I pitched two rehydrated packs into a 1105 IIPA @16, and a day after its faoming crazily and and the whole shed stinks of diacetyl
> wort was well O2'd and clean, I hopeign it will scrub out cos at the moment, its friggin stinky



In my experience, US05 and diacetyl production has a lot to do with stress - I get diacetyl in my IPAs but not my APAs. 

Personally, I quite like a bit of it in a big bitter beer.


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## bignath (1/11/11)

I've started getting it in my fake lagers. not sure why. I know some of the causes, but i treat all my beers (fake lagers, and apa's) the same so not sure why it's only noticeable in the megaswill killers.

My APA's aren't over the top - in fact are probably closer to an aussie style pale than a yank one. IBU's usually mid 30's, NZ hops, ABV though is usually 5-5.5 or thereabouts.

Don't use starters as yet. Have the gear pretty much good to go though. Rehydrated US05 to fermentis instructions, fermenting at 18/19/20 depending on beer.

Have a smack pack of 1056 in fridge, might chuck this in next fake lager and wash and reuse this just for those problematic ones.

Just done a NZ hopped rainwater pils, no additions, 90/10 Base malt and Munich 1. Best beer i've done period. No trace of diacetyl at all. Super clean beer, got me thinking about throwing it at a comp one day. Same process as fake lagers though so not sure why i "sometimes" get it and other times avoid it.


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## the_new_darren (1/11/11)

If yu put too much of the US56 (or what ever it is called now) into a brew, it will enevitably produce lots of diacetyl.

thats my experience from several years ago. In the end i gave up buying it and just use Wyeast 1056 now

cherrs

tnd


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## Bribie G (1/11/11)

Although US-05 and Wyeast 1056 are often touted as being virtual twins "Shit why go to all the trouble of smacking a pack when you can just rip the top off a trusty US sachet......." I find that the dried strain takes ages to clear, and hangs around the top of the fermenter with a half hearted little scummy head up to about day 10.
Like Darren I only ever use 1056 now for American Ales. But would love to see Pacman back again  

OT but there's a new yeast on its way from White Labs "San Diego Super Yeast" suited to Australian brewing conditions, can't wait to get my hands on some (the White labs guy will be at the Brisbane Home Brewing Convention on Saturday, better have some samples with him ) :beerbang:


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## DUANNE (1/11/11)

been using that sandiego super yeast a fair bit lately. an beauty of a yeast it is too. even fermented low at 15 for a fake lager it was finished in 4 days and it drops clean and clear quickly as well. i have found it doesnt come into its own until the second gen though.


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## Bribie G (1/11/11)

I'll have to get my hands on some, I've never used Whitelabs because I'm nowhere near a Brewcraft store and CB only stock Wyeast, so I wasn't aware that the superyeast was available. Thanks for the heads up


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## 2much2spend (1/11/11)

i would have to agree that my 2 encounters with diacetyl has been using us05.
from a starter not really from dried. 
i use liquid yeasts and so far no problems. it is pricey but i use the dregs from
the packet (pitched) to make a starter for next brew. it is working so far just
need to get my hands on some cheap Erlenmeyer Flask 2L so i can divide the
liquid yeast in to 4 starters.


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## super_simian (1/11/11)

sinkas said:


> I pitched two rehydrated packs into a 1105 IIPA @16, and a day after its faoming crazily and and the whole shed stinks of diacetyl





the_new_darren said:


> If yu put too much of the US56 (or what ever it is called now) into a brew, it will enevitably produce lots of diacetyl.



Is it perhaps an *overpitching* issue?


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## Maxt (1/11/11)

To add to my us05 lessons; this yeast takes longer to clear acetaldehyde than others I use. 
Especially with dark beers, if I kegged after a week at terminal gravity, I would get a green apple beer. Now I know to leave it on the yeast for an extra 3-5 days.


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## Mantis (2/11/11)

I use US-05 exclusively and get butter if I dont let the brew come up to 22 or so for a day or two at the end of ferment.


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