How long should a lager sit in primary?

About a week and a half ago I brewed a lager and have been fermenting it at 53 F. The yeast is Saflager S-23 which lists its optimal temp range 48-59 F, so I figure the temp is perfect right now. A professor I've been getting brewing info from told me soon I should rack to secondary and "lager" at 35-40 F for 4-8 weeks.

Is transferring the beer to a near freezing cooler going to hurt the yeast, which will be well outside their comfort zone?

Or is this what I want to do, as long as I wait until fermentation is complete before lagering?
What would happen if I lager too early?
Also, 4-8 weeks is a broad range; how long should the lagering stage last optimally?

you will want to transfer to a secondary and then lager for 4-8 weeks. If you don't transfer to a secondary the dead yeast will impart flavors into the beer. I don't believe there is an optimal lager time, at least not as a general rule of thumb, i would think it's based more on what you are looking for in your beer. i suggest researching lagering techniques so you can understand the process better which might answer these questions better.

Before you transfer it to another fermentor you might want to raise the temp to do a "diacetyl rest" if there is still activity in the airlock. If possible, bump it up a degree a day if you're using a temp controller or just move it to a warmer area and rouse the yeast a bit.

You're not going to hurt the yeast when fermentation is finished because lagering is basically stopping the yeast and getting them to fall out of suspension using cold temps.

As far as how long to lager, just try tasting your beer and if it tastes smooth and balanced and is relatively clear, it might be ready. There is no optimal lager time, the beer will tell you. Good luck!

Pretty sure I need that diacetyl rest...just found out about thermal shock leaving more diacetyl behind and this beer probably has a lot. After the rest, naturally I assume I need to lower the temp gradually to the lagering temp?

First of all, don't believe what you hear about autolysis (yeast cells bursting), or the off-flavors said to be imparted by leaving beer on the yeast cake too long. Myself and many on here have had no off-flavors after leaving a beer on the yeast cake for sometimes up to 6 months.

With lagers, I personally would rather let it sit in it's security-CO2-blanket than rack it and risk infection.

As for the D-rest, it should be done when your beer is roughly 75% fermented. Slowly raise your temperature to 60-65*F over two days. Leave it there for about 48 hours, then slowly lower the temperature to around 40*F over two days. Continue your lagering schedule.

I do like what I do for my ales- I leave them one month in primary, for all reasons I do ales. Then I do a diactyl rest for 3 days then I rack to secondary and lager for however long I lager for.

Here is a link to some helpful information about lagers. It gives you several options. I just got my lager in primary on Sunday. I will probably leave it in primary for a month at 50, do a diacetyl rest, then rack it to my keg for 4 months of lagering where I can keep it under CO2.

http://www.braukaiser.com/wiki/index.php?title=Fermenting_Lagers

bmurph said:

About a week and a half ago I brewed a lager and have been fermenting it at 53 F. The yeast is Saflager S-23 which lists its optimal temp range 48-59 F, so I figure the temp is perfect right now. A professor I've been getting brewing info from told me soon I should rack to secondary and "lager" at 35-40 F for 4-8 weeks.

Is transferring the beer to a near freezing cooler going to hurt the yeast, which will be well outside their comfort zone?

Or is this what I want to do, as long as I wait until fermentation is complete before lagering?
What would happen if I lager too early?
Also, 4-8 weeks is a broad range; how long should the lagering stage last optimally?

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You will need to check the gravity to know if you are ready to lager. If you are almost to the point where you expect the beer to finish you should rack to secondary. This will generally be 1-3 weeks depending on a number of factors (pitch rate, wort fermentability, oxygenation, temperature, etc.) In order to lager properly you need to lower the temperature by 1-2 degrees per day until you reach your lagering temperature. This will gently change the yeast over from their fermentation phase to their lagering (clean-up) phase. Traditionally you should lager a beer for 1 week for every 2 degrees plato (so SG 1.057= plato 14 gives 7 weeks lagering). I have also heard that this is not strictly necessary and 4 weeks is enough for most brewers (though I still try to wait the full time).

If you lager too early you will, in effect, create a stuck fermentation and your lager will finish at too high a gravity. My first few lagers all finished 1.020, which is really way too high for anything but a bock.

A great resource which I can't recommend strongly enough is Greg Noonan's "New Brewing Lager Beer". It is a fantastic resource for anyone interested in brewing a good lager and brewers in general. There are some things in it I don't necessarily follow (like his prohibition against dry yeast, I think that was a holdover from the first printing of the book in the 80s when dry yeast quality was lower), and he might push a little too hard for decoction mashing; but it is still a fantastic resource and I think you can get it on amazon for about $15.

Pivovar_Koucky said:

If you lager too early you will, in effect, create a stuck fermentation and your lager will finish at too high a gravity. My first few lagers all finished 1.020, which is really way too high for anything but a bock.

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Actually this beer is a bock...would it be wise to go ahead and lager when sg gets to 1.020 or a little lower?
If I did this and then pitched some more yeast at bottling, would they maybe get too active and cause the bottles to explode?

bmurph said:

Actually this beer is a bock...would it be wise to go ahead and lager when sg gets to 1.020 or a little lower?
If I did this and then pitched some more yeast at bottling, would they maybe get too active and cause the bottles to explode?

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Where are you expecting it to finish? Noonan says to begin to lower the temperature when you are like 3/4 done (from memory, so don't take it as gospel) and the yeast will continue to slowly eat the sugars during the lagering phase. I have found that the amount of fermentation during lagering is not much and accordingly I begin to lower the temperature when I am about 5 or so points above the expected FG. I wouldn't recommend trying to knock the fermentation out prematurely as this could result in bottle bombs or a cloying brew.

My FG should be 1.018 but I was going to do a diacetyl rest before lagering. How far through fermentation should I wait to D-rest? Reno_eNVy_446 says 75% but I assume this number doesn't have to be too precise...I wish I could say how far along I am but I don't keep the carboy at home to take a gravity reading (it stays in a cooler in a lab at my school--not so convenient for observation but otherwise I can't get the temp low enough, plus the lab has a brix I can use)

Honestly, I wouldn't worry too much about the precise moment to begin lagering. Also, a diacetyl rest is not strictly neccesary, unless you taste a microwave popcorn buttery flavor you don't have to do one. On the other hand, it couldn't hurt. Maybe when you get a chance check the gravity. If you are approaching 1.025-1.030 (depending on how long you want to d-rest for) you can allow the temp to rise to the low 60's (deg. F) for a couple days (this is also a good way to allow the beer to dry out if you are worried about stuck fermentation). Then you can begin the process of lowering the temperature to the lagering range (32-40 deg. F). Then all you have to do is wait wait wait.

I usually do it once the bubling in the airlock slow to once every three or four seconds. But the only real way is hydrometer readings and knowing your OG and expected gravity, but 2/3 to 3/4 done is about right.

Eight days ago this beer's SG was 1.041; took a sample today and it was exactly the same...I don't understand what I'm missing here. I've been watching it every day since I took the reading, steadily bubbling on average prob about 25 sec apart over the period. Temperature isn't the issue; both readings were at 60 F. Also I refrigerated both samples to take the yeast out of suspension. The OG was 1.059 and it's been fermenting 3 weeks. Can anybody tell me what might be going on?

I would guess that you have a stuck fermentation. You could try letting the temperature rise to 60 but its a bit early in the fermentation to do that (you could end up making some fruity esters). Alternatively, you could repitch the yeast. I might consider kraeuzening if I was you.

BryceL said:

Here is a link to some helpful information about lagers. It gives you several options. I just got my lager in primary on Sunday. I will probably leave it in primary for a month at 50, do a diacetyl rest, then rack it to my keg for 4 months of lagering where I can keep it under CO2.

http://www.braukaiser.com/wiki/index.php?title=Fermenting_Lagers

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do you start carbing in keg right away? I have my first two lagers going now...I hit each keg @ 30 psi to seal, but didnt think I would carb til a week before serving...

You're on the right track. You just need to hit it with CO2 to seal it and then you can disconnect it while you lager. About two weeks out from when you want to tap it, you can hook it back up and start to carb it up.