Lagering...

[SkiNuke]

I have always been confused by the notion of "lagering", compared to aging. A lot of it stems from people who say a lager is lagered because that's the only way to make one, usually with no proof that it does something special. Personally, I am inclined to believe that there is nothing special going on and it's the same as aging. As such, the only benefit I can see for "lagering" vs aging at cellar temps is that lagers would keep their flavor profiles longer.

Here is my rationale:
When you drop the temperature, fast or slow, you are making a harsh environment for the yeast. Their metabolism will slow and sooner or later they will go dormant. If the yeast are dormant then they can't really do much of anything. Which means that the changes that we perceive from lagering are just from random chemical reactions and perhaps some amount of settling, just like aging.

Thoughts?

 

[Thegreatestgray]

I read somewhere on this forum (I think yooper said it) but when you lager a beer it's a physical and chemical change that happens

 

[Yooper]

It's a complicated process, but I like braukaiser.com for an easy explantion:

When the beer is conditioned at low temperatures various processes take place that lead to the smooth character which is expected from a lager:
Proteins and polyphenols (tannins) form agglomerations (basically bind with each other to form larger molecules) which become insoluble and precipitate out of solution. [Nguyen 2007]
Hop polyphenols will drop out leading to milder hop bitterness
Yeast sediment which cleans up the beer and removes the yeasty smell and taste associated with young beer
Some of the alcohols and acids form esters in the beer which leads to new flavor compounds. This process is very slow and becomes only significant after more than 12 weeks [Narziss 2005].
Some yeast activity may be present which leads to further clean-up and extract reduction of the beer. I oftentimes see another extract drop of 0.1 - 0.2 Plato over the course of a few weeks.

from: http://braukaiser.com/wiki/index.php?title=Fermenting_Lagers#lagering.2Fcold_conditioning

 

[Spintab]

When you drop the temperature, fast or slow, you are making a harsh environment for the yeast. Their metabolism will slow and sooner or later they will go dormant. If the yeast are dormant then they can't really do much of anything.

Not sure of the answer to the main question but when you lager, you should drop your temps really really slow to prevent the yeast from going into complete dormancy. The whole idea is that they are at least a little awake during the process. If you drop too quick, they go completely dormant and you are merely cold aging at that point.

 

[SkiNuke]

Not sure of the answer to the main question but when you lager, you should drop your temps really really slow to prevent the yeast from going into complete dormancy. The whole idea is that they are at least a little awake during the process. If you drop too quick, they go completely dormant and you are merely cold aging at that point.

That's my point. It doesn't make sense to me that they wouldn't go dormant anyways. You're making a harsh living environment for the yeast, and they have nothing else to eat, all the sugar is already gone. Imagine you were up in the arctic with only your own feces to live off of, how long do you think you would last? One of the benefits of lagering I have seen floating around is that it gets the yeast to drop out of suspension faster. I feel like getting them to drop out of suspension and keeping them from going dormant are contradictory goals.


Yooper, wouldn't those reactions take place quicker at higher temperatures since there is more energy available? The dropping out of suspension part makes sense, but I feel like it would just take longer for that stuff to drop out if at a higher temperature (if there was a difference at all). Also, I was reading something from draft magazine about the science of aging (http://draftmag.com/cellar/required-reading-the-chemistry-of-beer-aging/) and it seems like very similar reactions are taking place compared to what you were talking about from braukaiser. I'm not saying there is no benefit from conditioning at low temperatures, I just want to clear up the idea that yeast do magical stuff during lagering. Also do you know of any side by side tests of cold conditioning vs cellar conditioning?

 

[BigRedHopHead]

Imagine you were up in the artic with only your own feces to live off of, how long do you think you would last?

LOL!! that analogy made me laugh so hard I spit my coffee all over my screen!!