when to check gravity for quick lager on 1.070 bock

[drunkinThailand]

Thanks for any help in advance

This is my first time doing a lager, and I would like to do the quick lager method (as passed on by brulosopher from others before him) but I would also like to minimize the number of times I open the fermentor to check gravity before ramping up the temperature for the diacetyl rest.

I am brewing a traditional bock using Mangrove Jack's Bohemian Lager yeast, with an og of 1.070. I pitched on Monday morning, saw bubbling this morning on Wednesday morning about 1 bubble every ten seconds.

How long should I wait to check the gravity? Brulosopher says 7-14 days, but that is quite a range. I would hope to only check it one time, that is my main goal here.

thanks again

 

[TheMadKing]

Well my first question is: why are you THAT concerned about opening your ferm chamber? The beer won't change temperature in a few minutes, so it won't really affect your beer to take a gravity reading. Your ferm chamber might warm a few degrees but the mass of cool beer will help bring that temp right back down again when you're done.

I would check it at the 7 day mark myself, though I've never made a lager that big.

 

[kh54s10]

I wouldn't open it for a gravity check at all. I would go somewhere between the 7-14 days (actually I would do 14 days) then do the diacetyl rest without a check.
That is, unless, I have any reason to think that the fermentation is not going well.

 

[SpeedYellow]

I wouldn't open it for a gravity check at all. I would go somewhere between the 7-14 days (actually I would do 14 days) then do the diacetyl rest without a check.
That is, unless, I have any reason to think that the fermentation is not going well.

^^ This. No need to check gravity and let in O2. Just wait until fermentation slows then do the d-rest. The brewing books say to wait until you're around 80% of the way to completion for the d-rest, but some folks lately have been pushing that toward 50% and claiming no ill effects. And other folks wait until almost the very end, or don't do a d-rest at all. So there seems to be a pretty broad range of what works. So no need for precision.

 

[kh54s10]

^^ This. No need to check gravity and let in O2. Just wait until fermentation slows then do the d-rest. The brewing books say to wait until you're around 80% of the way to completion for the d-rest, but some folks lately have been pushing that toward 50% and claiming no ill effects. And other folks wait until almost the very end, or don't do a d-rest at all. So there seems to be a pretty broad range of what works. So no need for precision.

The process that I went by was "time". Usually I recommend against using time instead of gravity readings, but the timing I used was 2 weeks fermenting, 2 days diacetyl rest and 2 weeks lagering. After 2 weeks I think the fermentation should be done. If not, 2 days at the higher temperature should finish it. If not, it should finish in the time it takes to drop from diacetyl temps to lagering temps. I ramp this down over the 2 weeks, so it starts off warm.

 

[SpeedYellow]

The process that I went by was "time". Usually I recommend against using time instead of gravity readings, but the timing I used was 2 weeks fermenting, 2 days diacetyl rest and 2 weeks lagering. After 2 weeks I think the fermentation should be done. If not, 2 days at the higher temperature should finish it. If not, it should finish in the time it takes to drop from diacetyl temps to lagering temps. I ramp this down over the 2 weeks, so it starts off warm.

Sure that probably works fine, but you could shave off a lot of time by merely watching for the fermentation to slow instead of waiting 2 weeks. Lager fermentations almost always slow by day 6-7 (if you pitched enough healthy yeast), so waiting another week would cause unneeded delay and would be doing a d-rest when the yeast are already done, which is definitely not ideal. But of course, this method requires the use of a bubbler airlock and monitoring every couple days.

 

[kh54s10]

Sure that probably works fine, but you could shave off a lot of time by merely watching for the fermentation to slow instead of waiting 2 weeks. Lager fermentations almost always slow by day 6-7 (if you pitched enough healthy yeast), so waiting another week would cause unneeded delay and would be doing a d-rest when the yeast are already done, which is definitely not ideal. But of course, this method requires the use of a bubbler airlock and monitoring every couple days.

I don't know. When I was researching lagers this was a method I found. It seemed a lot easier than constantly hovering over the beer. I have a programmable temperature controller so I just set it and walk away.

It worked very well for me. I don't know if doing the d-rest at an ideal gravity would have made my lager better, but I would put them up there with any commercial lager.

Like ales where some go 7 days then transfer to secondary and others leave the beer in primary for a month, I wonder how critical the timing is. I went with not so critical.

YMMV.

 

[SpeedYellow]

I don't know. When I was researching lagers this was a method I found. It seemed a lot easier than constantly hovering over the beer. I have a programmable temperature controller so I just set it and walk away.

It worked very well for me. I don't know if doing the d-rest at an ideal gravity would have made my lager better, but I would put them up there with any commercial lager.

Like ales where some go 7 days then transfer to secondary and others leave the beer in primary for a month, I wonder how critical the timing is. I went with not so critical.

YMMV.

Yes we totally agree. I'm just saying you can shave some time off. And it seems undisputed that the yeast will clean up diacetyl & precursers quicker when they're still active. So I wouldn't expect your 2-week fermentation to make worse beer; just slower.

But personally, if I waited until day 14 for a d-rest, I'd give it a very long d-rest, like 10 days. That's just me, because in the dozens of lagers I've made, I've gotten burned by 3-day d-rests a couple times. Now I wait until fermentation slows then do 5-6 days.

 

[Yooper]

I would just raise the temperature to the diacetyl rest when signs of fermentation slow- like the krausen falls, bubbling in the airlock slows, etc. That for me is usually about 5-7 days.

I do that even when I'm not doing a "quick method" though- fermentation always takes the same amount of time generally, whether abbreviating the lagering phase or not.

 

[drunkinThailand]

Thanks for all the input. I think I'll go with waiting for activity to slow and then ramping it up to d-rest (around day 6 or 7 or maybe wait an extra day just to be safe) in the name of saving time.

I was just wondering, from what I've seen most people around here like to let there ales ferment for 3 weeks to clean up even if finished earlier than that. Why is it that not the case with a lager?

 

[TexasDroughtBrewery]

I would just raise the temperature to the diacetyl rest when signs of fermentation slow- like the krausen falls, bubbling in the airlock slows, etc. That for me is usually about 5-7 days.

I do that even when I'm not doing a "quick method" though- fermentation always takes the same amount of time generally, whether abbreviating the lagering phase or not.

I agree with Yooper that I usually do the 5-7 day point. Then 2-3 days D-rest I don't really ramp it down..I just take it out of my fridge put it in my house which sits around 72 degrees and it will slowly come to the rooms temp in those 2-3 days which has worked for me. Then ramp it to 34 for the next week or two.

 

[Yooper]

Thanks for all the input. I think I'll go with waiting for activity to slow and then ramping it up to d-rest (around day 6 or 7 or maybe wait an extra day just to be safe) in the name of saving time.

I was just wondering, from what I've seen most people around here like to let there ales ferment for 3 weeks to clean up even if finished earlier than that. Why is it that not the case with a lager?

I wouldn't say "most people" leave their ales in primary for 3 weeks. I certainly don't. I think there is a very vocal minority that do it.

That "clean up" takes up to about 24 hours once fermentation ends and the beer is at FG. If it's done, it's not going to get doner. I generally leave my ales in the fermenter for a few days after fermentation ends, so that the clean up is done and the beer is clear, but I can't think of a time I left it for three weeks. At least, not on purpose. Sometimes life happens and the beer may sit longer than I intended, by I generally am packaging my ales by day 14 or so.

 

[TheMadKing]

I wouldn't say "most people" leave their ales in primary for 3 weeks. I certainly don't. I think there is a very vocal minority that do it.



That "clean up" takes up to about 24 hours once fermentation ends and the beer is at FG. If it's done, it's not going to get doner. I generally leave my ales in the fermenter for a few days after fermentation ends, so that the clean up is done and the beer is clear, but I can't think of a time I left it for three weeks. At least, not on purpose. Sometimes life happens and the beer may sit longer than I intended, by I generally am packaging my ales by day 14 or so.

100% agree.. My typical grain to glass for an average OG ale is 15 days.. I'll usually age longer for darker and bigger beers, or go quicker for hefeweizens

For my lagers its 28 days

 

[drunkinThailand]

Wow, good to know. I will have to give that quicker turnaround a try. Would certainly be nice to shave a week off of things.