# Diacetyl And Lagering



## MattC (5/9/07)

Hi all,

At present I have a coopers brewmaster selection Pilsner which I brewed with saflager S-23 yeast. It was in the primary for 8 days before I transferred it to the secondary, where it has been for 5 days. It has been at 1020SG for 3 days now. OG was about 1064. On the last SG test I took a good whif and ahd a little taste. It was extremely fruity.

My questions are

1. will this fruity taste dissipate?
2. What are diacetyl rests and do i need to do one with a lager?
3. What is lagering?
4. Should I bottle it?

Regards


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## Steve (5/9/07)

MattC said:


> Hi all,
> 
> At present I have a coopers brewmaster selection Pilsner which I brewed with saflager S-23 yeast. It was in the primary for 8 days before I transferred it to the secondary, where it has been for 5 days. It has been at 1020SG for 3 days now. OG was about 1064. On the last SG test I took a good whif and ahd a little taste. It was extremely fruity.
> 
> ...




1. Depends what temperature you brewed it at with the lager yeast you used. If brewed at 20+ degrees then you're prolly stuck with the fruit. Lager yeasts are meant to be brewed between 9-15 ish

2. Diacetyl rests are usually done just before primary is finished. At about 1020 raise the temp of the fermenter to room temp for 24-48 hrs. Then rack to 2ndary.

3. Lagering is cold conditioning your 2ndary fermenter for as long as you can wait. It helps clear the wort.

4. If you dont want to lager it, then yes bottle it.

Cheers
Steve


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## BoilerBoy (5/9/07)

What wasa the primary fermentation temp


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## BoilerBoy (5/9/07)

just got in before me Steve  

Cheers
BB


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## Inge (5/9/07)

1. Hard to say... What temperature did you ferment at? This fruity taste could be one of a few things, but the most likely scenario is that the brew was fermented at a higher temperature i.e. over 13 degrees C. It could also be acetaldehyde, which is fairly normal in young beer and will dissipate with age.

2. Diacetyl rest refers to a period at the end of fermentation where you allow the temperature of the ferment to rise to 18-20 degrees for 2 days or so. What it does is speed up the activity of the yeast, allowing them to eat up any residual diacetyl, a compound which kind of tastes like the smell of butter (which is less than ideal in a lager).

3. Lagering refers to leaving the beer to condition for weeks or months at low temperatures. You are using bottles, so whack them all in the fridge for a month or two.

4. If the final gravity is stable, then bottle it.

Hope this helped mate.

Edit: Beaten!


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## afromaiko (5/9/07)

MattC said:


> At present I have a coopers brewmaster selection Pilsner which I brewed with saflager S-23 yeast. [snip] It was extremely fruity.



"Fruity" would perfectly describe my experiences with S-23, even when fermented at 10C.


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## MattC (5/9/07)

afromaiko said:


> "Fruity" would perfectly describe my experiences with S-23, even when fermented at 10C.




Thanks Boys I had the temp about 16 the entire way through!!


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## afromaiko (5/9/07)

Lately I've been trying out W34/70 and it's been a lot cleaner and has a dryer finish. However I have noticed that it produces a bit of sulphur, but that gradually disappears with age or the occasional keg burping. From the reports I've been reading here I'm keen to give the S189 a shot soon.


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## Steve (5/9/07)

afromaiko said:


> Lately I've been trying out W34/70 and it's been a lot cleaner and has a dryer finish. However I have noticed that it produces a bit of sulphur, but that gradually disappears with age or the occasional keg burping. From the reports I've been reading here I'm keen to give the S189 a shot soon.




S189 :super:


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## KGB (5/9/07)

Check out this link , its got a bit of info about diacetyls and lagering.

What I'd like to know is when is a diacetyl rest necessary? I've read that its not always needed depending on the temp the yeast is pitched at and the wort is when fermentation starts or something...?
I know diacetyls are consumed at around 20 degrees, but are they produced if the entire fermentation is done at ~12 degrees? From what I understand, starting this low can take a long time for the yeast to get going so brewers often start at closer to 20 and then bring it down gradually to 12 degrees and the initial period of higher temps is when the diacetyls are produced.

Am I on the right track or am I completely off?


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## MattC (5/9/07)

Inge said:


> 1. Hard to say... What temperature did you ferment at? This fruity taste could be one of a few things, but the most likely scenario is that the brew was fermented at a higher temperature i.e. over 13 degrees C. It could also be acetaldehyde, which is fairly normal in young beer and will dissipate with age.
> 
> 2. Diacetyl rest refers to a period at the end of fermentation where you allow the temperature of the ferment to rise to 18-20 degrees for 2 days or so. What it does is speed up the activity of the yeast, allowing them to eat up any residual diacetyl, a compound which kind of tastes like the smell of butter (which is less than ideal in a lager).
> 
> ...


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## matti (5/9/07)

If you like the fruityness, keep brewing with it! 
Otherwise brew with yeasts that suit the temperatures that you can ferment in.

My predicament was that I could only brew ales in spring and autums as the shed got to warm for ales yeasts and the brew fridge was to cold for ales yeast.

Consequently I read up about lagers and the procedure so I could brew lagers all around the year.

Saflager s-23 is a fruity lager yeast and i stick W34/70 or S189. 
These are a bit dustier and take a long time to settle in bottle.

US05/US56 is a great Ale-yeast you can brew around 16-22 degrees. 

S-04 is a yeast that I started with kits and they are really nice providing the ferment temperature are steady.

matti


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## MattC (6/9/07)

Matti, you said you brew lagers all year round and ales in spring and autumn. Do you use a brew fridge for lagers??? My fav style of beer at the moment are pilsener type beers. what yeast or yeast is the best for these? and what yeast could I get away with using.

I live in northern NSW and I do not have a fridge for fermentation.


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## mfeighan (14/6/09)

sorry for an old dig up but...
i have a lager in my fridge at the moment. Using proculture's liquid yeast Pro-77 (i guess its close to wy 2042)

PRO- 77 Danish Lager yeast
A dry finish that helps the hop aroma and taste to prevail. Mostly used with light lagers requiring little taste influence from the yeast.

Flocculation: Low Attenuation: 73-77%
Temperature Range: 8-13C Alcohol Tolerance: 9%

i pitched at 15 deg land lagered at ~9 deg

fermentation fridge smells pretty sulfury. its attenuated from 1048-1020 in 1 week.
i have tasted and cant taste the buttery flavors mentioned 

do i need to give it a diacetyl rest, the sulfur smell isn't apparent in the beer, just the fridge. i also think it may be a bit hard bringing the temps up to ~20deg as it has been pretty cold lately

i will be cc/lagering in a keg for ~ 3 weeks after secondary fermentation


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## RetsamHsam (14/6/09)

Mikey said:


> sorry for an old dig up but...
> i have a lager in my fridge at the moment. Using proculture's liquid yeast Pro-77 (i guess its close to wy 2042)
> 
> PRO- 77 Danish Lager yeast
> ...



I would give it a rest at higher temperature, it will definitely help to clean up any remaining sulfur produced during fermentation.

It's not as hard as you think to get the temp up in your fridge. Just grab 2-3 empty milk/soft drink bottles and fill them up with hot water from the tap and chuck them in the fridge before you go to bed each night this will get the temp up to about 20-22 degrees.


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## manticle (14/6/09)

Nothing to lose by doing it so why not? Maybe even bring it inside for a day or two (high krausen should have well and truly passed).


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## mfeighan (7/7/09)

thanks for the advice
after i raised the temp to ~20 deg (just moved it into a small room with a heater on a thermostat) after 2 days sulfur smells dissipated and smelt like beer again. lagered in keg for 2 weeks.
just had 2 kegs of the stuff on sat night. Got emptied pretty fast


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