Diacetyl Rest For Us-05

[DJR]

I reckon the instructions about doing a D-rest at lower temp for a couple of days are aimed at commercial brewers. In commercial brewing time is everything, fermenters that store a beer for twice as long produce half as much revenue. Just keep it in the fermenter for a few days and everything will be fine.

Not sure whether reducing the temperature would work that well for VDK reduction, it'd be better to rouse the yeast up if it starts to floc early, wait for it to condition, crash chill it for 3 days and be done with it.

After having gone through many many rackings early on nowadays I just leave the beer for 3-4 weeks in the fermenter and then bottle - and the beer is just as good if not better, racking is over-rated IMHO and often leads to unnecessary oxidation

 

[DJR]

At what temperature for an ale do you CC? Around 15 as suggested with the Fermentis pdf?

Lower, esp. with US05 that doesn't flocc very well, even down to lager chill temps 0-10C. Don't have a fridge anymore but about 4-8C for a couple of days really helped US05 drop bright and clean when I did. Just keep it around for a couple of days first for diacetyl reduction and warm conditioning, then crash it

 

[manticle]

Cold condition so as cold as possible. Between -1 and 4 degrees. Same/similar to lagering.

 

[gazeboar]

Excellent, thanks lads. Quite simple really, despite all the initially perplexing jargon and acronyms when I first arrived at this site, which I think I have now grasped the basic concept of
Just one more thing, suppose I crash down to 8 degrees to aid flocculation. Do I need to bring it back up to 20 when it comes to bottling? Or can I bottle straight from the fermenter at 8 degrees into bottles in my cupboard (26). I can't see how it would affect anything but thought I should probably check anyway. Common sense tells me one thing, but paranoia another.

 

[Steve@PMF82]

Might be worth an email to fermentis for clarification. Their info is usually pretty thorough and detailed but that goes against what I have read and experienced. Normally a week at ferment temp for ales is enough to remove acetaldehyde and diacetyl.

I did just that earlier this evening, will report back with any info they shoot my way.

 

[manticle]

Excellent, thanks lads. Quite simple really, despite all the initially perplexing jargon and acronyms when I first arrived at this site, which I think I have now grasped the basic concept of
Just one more thing, suppose I crash down to 8 degrees to aid flocculation. Do I need to bring it back up to 20 when it comes to bottling? Or can I bottle straight from the fermenter at 8 degrees into bottles in my cupboard (26). I can't see how it would affect anything but thought I should probably check anyway. Common sense tells me one thing, but paranoia another.

No need to warm it up again. Obviously the bottles need to be around ferment temps for the yeast to eat the priming sugar and carbonate but they can get there naturally. Bottle at 8 (or lower if you can manage it).

@beer4u: good stuff.

 

[DJR]

Do I need to bring it back up to 20 when it comes to bottling? Or can I bottle straight from the fermenter at 8 degrees into bottles in my cupboard (26). I can't see how it would affect anything but thought I should probably check anyway. Common sense tells me one thing, but paranoia another.

You only need to worry about that if any fermentation has actually occured at the lower temp in which case more CO2 will be dissolved in the beer as more CO2 can dissolve at lower temps. If you're just doing it after the gravity hasn't dropped, don't worry about it. Otherwise you'll need to factor it in and bottle accordingly, e.g. when brewing lagers cold and bottling without doing a diacetyl rest

 

[gazeboar]

No need to warm it up again. Obviously the bottles need to be around ferment temps for the yeast to eat the priming sugar and carbonate but they can get there naturally. Bottle at 8 (or lower if you can manage it).

Awesome! This is going to be golden when I crack the first of these brews Never again will I have a one-dimensional appreciation of beer. :blink:

 

[Steve@PMF82]

Might be worth an email to fermentis for clarification. Their info is usually pretty thorough and detailed but that goes against what I have read and experienced. Normally a week at ferment temp for ales is enough to remove acetaldehyde and diacetyl.

I did just that earlier this evening, will report back with any info they shoot my way.

I got a reply, make of it what you will.... :huh:

Message : Hello

I have a couple of questions about US- 05 brewers yeast.

In your tips and tricks you say that to perform a diacetyl rest using this yeast you should LOWER the temp a few degrees?

Most text and discussion i have encountered suggests that letting the temp rise a couple of degrees at or near the end of final gravity will help keep the yeast active and clean up any fermentation by-products such as diacetyl.

I note you recommend this approach with your lager yeasts.

So how does lowering the temp and presumably slowing down the yeast activity help eliminate by-products?

One example: many people like to brew a faux lager style beer with US-05 at 15 - 16 degrees Celsius, results in a long slow fermentation and usually one would let the ferment temp rise 2 - 3 degrees at or near the end to spur on some extra yeast activity and hopefully clean up any unwanted fermentation by-products such as diacetyl.

I am genuinely interested in an informative reply.

Thank you for your time.



Dear Stephen,

Diacetyl chemistry and biochemistry for ale and lager yeast are the same.

Generaly Lager yeast are more active at low temperature then ale yeast.

Therefore Lager yeast could be more efficient for diacetyl reduction at low temperature then ale yeast.

15-16 C are not critical temperature for Safale US05 but of course fermentation will be slower.


Kinds regards.



Yves Gosselin.

Yves GOSSELIN
Technical Manager

Tel. +33 (0)3 20 81 62 75

Mob. +33(0)6 85 25 89 64

[email protected]

www.fermentis.com

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