Is diacetly rest a common thing to do? If yes, how shall I do it?

[Elysium]

I have brewed 7 batches with a friend and never done a diacetly rest. I am wondering if we should start doing it? I mean I dont want any flavour (compounds) in my beer that shouldnt be there....so we might as well learn how to do this, right?

By the way....are there any good links with info on how to do it? I mean good links..as in trustworthy links with good practise of the process.

UPDATE: I dont brew lagers. I brew ales. Shall I do it with my ales? At what temperature?

 

[WoodlandBrew]

Yes, it is common when brewing a lager. Ales are fermented at temperature that allow diacetyl to be absorbed so no actual "rest" is needed. The beer can be just left in the fermenter for a few extra days to acomplish the same results.

Here is some good information from Kai:
http://braukaiser.com/wiki/index.php?title=Fermenting_Lagers

 

[kiwibrewer]

I've been playing round with DiAc rests in my lagers. I hit it up to 18 from 12 in the final 2-3points before terminal. I find it helps really clean up the profile, including some of those unpleasant sulphur notes associated with lager strains.

Good luck

 

[FuzzeWuzze]

As stated, you only do D-Rests on Lagers.

You want to do them when the yeast is still active though, but not until near the end of fermentation.

So you have your starting gravity, and should have a rough idea of the final gravity you will get with your yeast.
You want to bring it up to 65ish once your wort is about 80% done with fermentation, this gives the yeast time to clean everything up while they are still active.

For example if your doing a 1.064 lager and it ends at 1.014, you would D-Rest at around 1.024 and let it sit for a few days until the beer is fermented out. Then lager it like you would normally.

 

[ajdelange]

Do your beers taste/smell of diacetyl (buttery smell like movie theater lobbies in the days before it was made illegal)? If not, why worry about this?

Yes, it is a common practice in lager brewing to use diacetyl rests because you can shorten the length of time before the beer is out the door by doing one as opposed to the traditional slower process. As you might expect this reduces the quality of the beer somewhat but not by that much.

 

[FuzzeWuzze]

Do your beers taste/smell of diacetyl (buttery smell like movie theater lobbies in the days before it was made illegal)? If not, why worry about this?

Yes, it is a common practice in lager brewing to use diacetyl rests because you can shorten the length of time before the beer is out the door by doing one as opposed to the traditional slower process. As you might expect this reduces the quality of the beer somewhat but not by that much.

Doing a D-Rest doesnt change the fact you need to lager for many weeks.
Ive never heard of anyone stating it affects the beer for worse, if anything it's a necessity for every lager. Some yeast strains or lager styles might not need it, but in general I was under the impression its something you should always do because it really doesn't take much effort and can only make your beer better.

 

[ajdelange]

As I said in #5 the diacetyl rest program was developed because it produced acceptable beer without the long glide to lagering temperature followed by 3 months (the traditional) time for lagering. And the beers produced using it are indeed acceptable. I wouldn't even suggest that I'd be able to tell one made with the traditional program from one made using a diacetyl rest but the ones made the traditional way are going to be marginally better. I don't do diacetyl rests so I can't compare but one thing I do remember from the texts is that the traditional beers have better head and head retention and I have noticed that mine do pretty well in that department - the much sought after 'meringue' head. Also the stability is fantastic. I can drink and enjoy these beers easily a year after they are made and sometimes up to 2 years though finally the diacetyl does begin to creep back up.

There is no need for a diacetyl rest in a properly made lager. If you understand the mechanism of diacetyl production (it is produced in the package by non enzymatic oxidation of alpha acetolactate) you will understand why long lagering on the yeast disposes of it. The diacetyl rest is a shortcut - and an pretty effective one too. I don't mind lagering a beer for 9 months because I can be drinking it a couple of weeks into the lagering process but my methods (the traditional one with some modifications) would be a financial disaster for a commercial operation).