When to give it a rest...

I am currently in the primary fermentation of an Oktoberfest, and it still looks quite active. see here: https://www.homebrewtalk.com/f13/should-i-brew-today-79003/

This beer has been fermenting for one week at between 51 - 54 degrees.

Anyway, I want to include a diacetyl rest before I rack to the secondary, then bring it down a few degrees a day to lagar temps. I started with an OG of 1.080 at 70 degrees, so what should I expect for a hydrometer reading before I let the temp rise for the rest? And how long should I wait to take the reading, should I give it a few more days as long as it still looks active?

I have been reading everything I can on the diacetyl rest process and my understanding of it is: ferment until 2/3 complete, bring to room temp (60-65), rest for 2 days, rack to secondary, back into fridge, lower temp 3-5 degrees per day until lager temps are reaches (32-35).

It's actually a very intuitive thing. Watch it like a hawk, and as soon as it looks like it's thinking about starting to slow down, take it out of the fridge.

swapped the blowoff tube for the airlock last night. still getting pretty good activity, bubbles every couple of seconds, and the krausen is still pretty high and active. I'm guessing another 4 or 5 days till rest.

I took a hydrometer reading last night. I started with a much higher OG than anticipated (1.080), as of last night I was sitting at 1.048. airlock is still burping every 5 to 7 seconds, and the krausen has dropped a little, but still looks quite active.

I'm gonna give it another day or two, then take another reading.

Its been running for 14 days now, and still chugging along. Tasted the sample last night, and seems to be pretty good. A little buttery, but am hoping the rest will clear that up.

I think you're right- the diacetyl rest will take care of the off-flavor. Some yeasts produce a ton of diacetyl, some produce very little. I've actually skipped a diacetyl rest quite a few times, because it wasn't needed. It's a good thing you've been planning one all along.

OP, you're right on everything, but I would wait a little longer for the D-rest. D-rests don't need to be done until the beer is 6 points shy of target FG. Of course, it doesn't have to be exact, so just ballpark it. It's better to be a little early than to miss it all together.

And how long do you plan to lager?... that looks like a 10-weeker!

10 weeks for a 1.080 beer? Whoa!

I wonder what my Negra Modelo is going to need...

menschmaschine said:

OP, you're right on everything, but I would wait a little longer for the D-rest. D-rests don't need to be done until the beer is 6 points shy of target FG. Of course, it doesn't have to be exact, so just ballpark it. It's better to be a little early than to miss it all together.

And how long do you plan to lager?... that looks like a 10-weeker!

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I gave it another day, and it had slowed down a little more, didn't take another reading, just took it out. It has been sitting at 63 for a couple of days.

fermentation took back off pretty heavy for awhile, and has now slowed back down. I hope it is done by tomorrow morning. I will take a reading then.

The bad part about this is I am leaving for two weeks, so I had to get this done before I left. I was expecting the beer to finish primary earlier, but I guess they just have a mind of thier own

I probably should have given it a few more points before taking it out, but I hope it turns out OK.


I was figuring 8 to 10 weeks to lagar.

edit: nevermind

Seawolf said:

Does lagering need to be done in a secondary? If I pull my lager out for a D-rest, should I rack it, or leave it?

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Good Question!


Since I have to leave town for a couple of weeks (damn you work!), and I'm not sure this thing is really "finished" in the primary, am I ok to lagar in the primary, or even start it for a couple of weeks, then rack?

My wife will be monitoring the lagar fridge temp, and stepping it down using the controler.

Ceedubya said:

Good Question!


Since I have to leave town for a couple of weeks (damn you work!), and I'm not sure this thing is really "finished" in the primary, am I ok to lagar in the primary, or even start it for a couple of weeks, then rack?

My wife will be monitoring the lagar fridge temp, and stepping it down using the controler.

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It depends on the timing. This is a tough one as your timing is bad with having to leave. Ideally, lagers are removed from the primary very soon after primary fermentation (and D-rest). This is because the longer it sits on the trub the more it can absorb compounds that will end up being "off-flavors" in the final beer (decaying yeast, precipitates, etc.) However, with a beer of that high an OG, I think 4 weeks in primary wouldn't be bad. Anymore than that and it will get a bit more risky.

menschmaschine said:

I think 4 weeks in primary wouldn't be bad. Anymore than that and it will get a bit more risky.

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Is it true for ales too? I have a hefe 3 weeks on primary (in 58F) and still active. I wonder if I can give it one more week.

Piotr said:

Is it true for ales too? I have a hefe 3 weeks on primary (in 58F) and still active. I wonder if I can give it one more week.

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I guess my answer would be yes and no. While it happens the same for ales as with lagers, you don't notice it as much. So, one could say the time threshold for ales in primary is a bit longer (after fermentation complete) than lagers. Most lagers are very sensitive to off-flavors because they are supposed to taste very clean and have little to no yeast-related flavors. Plus it's not so much about total time in primary as it is about time after fermentation is complete. For ales, a good week+ in the primary after fermentation is complete is good for conditioning (as long as it's not going to secondary at all).

after 2 1/2 days at 64 degrees, the airlock had slowed to three burps per minut. Took a hydrometer reading, and was sitting at 1.034. I decided to go ahead and rack into the secondary.

over the last couple of days, have brought it back down to 50. I'm thinking I'll leave it here for a couple of days, and then work it down to 35, 4 degrees at a time, for lagaring.

How much more do you think I can get out of the yeast in the secondary? Am I gonna break 1.020? Remember, this beer started at 1.080.

Took a taste from the hydrometer reading, was very good. after lagaring, and once its carbonated I'm hoping this beer is gonna be great :rockin:

Well, it would have been better to wait until there were no signs of fermentation before racking. 1.034 seems a bit high. Now you only have the yeast in suspension to work with, so I'm not sure how much lower it will come. I can say that in typical lagering, you get maybe a 1/2 a point to 2 points during lagering, but this is after primary fermentation is complete. Ah well, live and learn... I'm sure it will still end up good enough to drink!

Looks like you were right

I had to wife bring it down to 48, and hold for a few days till I returned. I took a gravity last night, and it came in at 1.030.

so I have lost a few more, but not what I was hoping for. Fermentation has slowed WAY down, bubbles every 20 seconds. I'm gonna let it run a few more days and then continue stepping it down to lagar.

The good news is, it tastes great and since I started with such a high OG, it does have plenty of alcohol in it.

Hopefully I can pick up a few more points during lagar??

Also, since I am lagaring for so long, am I going to need to add some dry yeast to bottle?