Lagering question

ziggy13 · 11-11-2009, 06:58 PM

Hey guys,

I have read Charlie Papizians' two homebrewing books and they have left me with this question about making lager. You start fermentation at room temp, once it's started drop it to 50 degrees or whatever the yeast strain wants, wait a week or two then transfer to secondary, wait another a week or two until it's done fermenting...now here's my question. Since the whole time the beer has been fermenting it has been in the fridge at lagering temperatures, is that considered lagering, or do you leave the beer in the fridge for another two weeks AFTER it's done fermenting to actually lager it? Also, once bottled do you want to put those bottles in the fridge to condition or should they condition at room temperature? Finally, is there any point to let the beer come back up to room temperature at the end of fermentation to ferment out what the yeast couldn't get at while at lagering temperatures?

Thanks a lot in advance!

**TexLaw** · 11-11-2009, 07:52 PM

First off, I highly recommend reading Noonan's (RIP) New Brewing Lager Beer, if you are interested in brewing many lagers. It's a great book and readily available.

Second, when you are fermenting your beer at lager yeast temperatures, that is not lagering. That is just fermentation. Lagering occurs after fermentation, when you hold your beer at 34F (or as close as you can reasonably get to that) for some period (typically 1-3 months). You can do that in the fermenter, in a keg, or in bottles.

Third, you usually need closer to that 2 weeks to ferment a lager (if not more) than the 1 week. You need to give lager yeasts plenty of time, as they work more slowly than ale yeasts. You might need three weeks in the primary before you consider racking.

Fourth, with a healthy lager yeast (i.e., good starter, good nutrients, fresh enough yeast, proper pitching rate, and proper temperatures), you should reach full attenuation without having to raise the temperature. That said, there are some lager yeasts out there that have a bit of a reputation for stuck fermentations. WLP838 is the only one I can think of, right off hand. Still, it's a good idea to keep a little closer eye on your lager fermenation until you get to know the yeast a bit, just in case.

Finally, yes, you need to condition the beer in the bottle at room temperature. Otherwise, it might take you something close to forever to get your conditioning done. If you like, you actually can condition lagers at 50-55F, but you might have to protect your beer from the zombie apocalypse. Don't worry, while conditioning lagers at room temperature is not optimal, you probably won't even notice the difference.

On the matter of temperature, you may have heard of a diacetyl rest. All yeasts produce diacetyl during fermentation, some more than others. Lager yeasts, as a whole, are no better or worse about it than ale yeasts. However, the cooler fermentation temperatures sometimes cause the lager yeasts to shut down before they have gone back and "cleaned up" (i.e., metabolized) the diacetyl. If that turns out to be the case, you can do a diacetyl rest, where you let the beer come up to ale fermenting temperatures for a a couple days, waking the yeast up to the point where they clean up. Diacetyl often is not as large of a problem when bottling, though, as you have that extended conditioning period at room temperature. That's just an FYI.

TL

boo boo · 11-11-2009, 07:59 PM

To further TexLaws post, it isn't really recommended you start fermentation warm and then cool to actual fermentation temps, but rather, pitch cold or fermentation temperture yeast into wort that is at fermentation tempertures or slightly below.

Lager yeast fermentations started warm will produce more esters, diacetyl and fusels than a true lager should have. In other words, it most likely will taste either fruity or other tastes assiciated with diacetyl and fusels.

**TexLaw** · 11-11-2009, 08:01 PM

Thanks, boo boo. I was just coming back to add that. It's really the esters that'll get you, more than anything else, when you start warm and then cool down.

TL