Diacetyl rest

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Oneandone

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Doing a Maibock kit from NB using OYL-111. It’s In primary stil between 51-53 in my freezer. Kit calls for a Diacetyl rest after lagering and before i bottle but With my reading I have been doing it may be something to do it after primary fermentation slows down. Should I do a double diacetyl rest one after primary fermentation slow and one before bottling? Or one or the other.

Also should I have had the fermentation temp lower than the 51-53 that I have it at now?
 

GoeHaarden

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Yeah, D-rest is typically done in the last 20-ish percent of fermentation. Not very specific just towards the end really. But before lagering or packaging.

How long have you been fermenting? I just ramped my lager for a D-rest today and I brewed last friday. I have a tilt so I have a better idea of where fermentation is, but prior to that I would do its between 5-7 days. My lager started at 1.041 and I started to raise temp at 1.020.

Your temp is within that yeast range so I wouldn't worry about it.
 
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Oneandone

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I am on day 4 and was hoping to test it with the hydrometer around Friday or Saturday. My SG was at about 1.064
 

Kickass

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I don’t ferment many lagers at true lager temps. That said, when I do, I do a d rest around the last 15-30% of fermentation. Then lager, then package. No second fermentation, no double d rest, nothing fancy here
 

GoeHaarden

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I am on day 4 and was hoping to test it with the hydrometer around Friday or Saturday. My SG was at about 1.064
Yeah, you could take a sample and see where your gravity is or you could just raise temp in a day or two and avoid all the possible problems of opening up your fermentor.

Did you, by chance, make a starter for this brew? It's a pretty big lager and one pack of yeast would be a severe underpitch.
 

Punx Clever

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The way I understand the process of yeast cleaning up diacetyl...

The Diacetyl precursor, alpha-acetolactate (AAL), is produced as a byproduct of active fermentation. It oxidizes to diacetyl, at which point the yeast will convert it into diols, which have a much higher taste threshold. This process requires active yeast and is aided by slightly higher temperatures.

So, you want to raise your fermentation temperature a few degrees (I always go to 65*F) for a few days (I do 3 days) to allow the precursors to oxidize when fermentation is nearly complete (I target the last 25%) so the yeast can convert it.

If you can't actively monitor your gravity, It's a safe bet to raise fermentation temperatures when airlock activity slows.
 

dmtaylor

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Yeast will eat diacetyl, if given warm temperatures and enough time. When bottling, just do the diacetyl rest in the bottles as part of the carbonation step. Keep the bottles at a reasonably WARM temperature for a couple of weeks. Then chill one bottle, pop it and see if it has any diacetyl. If not, you're done. If yes, then give it another week or two, at WARM temperatures, then repeat. It should not take longer than 4 weeks for diacetyl to disappear completely from your bottles, at least about 90% of the time.
 

Mark3885

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I’m finishing up an Irish Red , fermented at 66f , when airlock slowed to a bubble per minute, I ramped up the temperature to 74 over 2 days . It’s been 10 days and fermentation has stopped. Now I’m cold crashing to 34F for 4 days , then I’ll keg. This is pretty much my same procedure for most beers , never off flavor , always good beer .
 
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