Is secondary fermentation necessary?

IMO, secondary isn't necessary for most beers.

 

I think it depends on the beer.

Most beers would be fine with a few months on yeast cake.
I’d be skeptical to leave a really big beer (10%+ abv) or acidic beer on yeast for extended time.

Ie. if I were doing a big stout or barleywine in a carboy I would probably transfer to a purged keg after 2-3 weeks to condition.

 

The general consensus around this forum has been that using a secondary fermenter can create accidental exposure of air/O2 getting into your beer, thus it is unnecessary. However, a secondary fermenter is recommended for beers being aged on wood chips/spirals or on fruit. Cold lagering is another example to use it if you are brewing a beer in that family.

 

Simply means all the yeast that has settled out, typically in the primary fermenter. One of the often-cited reasons for secondary is to transfer the beer off the yeast cake. When the yeast die, they may release compounds that are desirable in the beer. The longer the beer sits on the yeast, the greater the risk. But I think most would agree the risk doesn't come into play for at least a month or two, and possibly longer than that.

You'll also see people talk about the yeast cake in the context of repitching, i.e., putting a new wort on the yeast cake to ferment a new beer. But that's a different conversation.

 

Without secondary fermentation ... bottled beer would be flat.

 

Yes, there will be more than enough yeast still in suspension.

 

My personal preference is to package the beer after no more than 3 weeks in the primary. Letting the beer sit too long (everybody likely has their own opinion what "too long" means) has risk of effects of yeast autolysis. If you chose to let your beer sit in the primary for an extended period of time it would be prudent to store the beer cold since cold temperature will mitigate the effects of yeast autolysis.

Cheers!

 

Yeast cake is settled out yeast. Most yeast falls to the bottom of the fermenter within 2-3 weeks of fermentation.
From this point out, you will want to worry about yeast autolysis and oxidation.
Autolysis is basically the breaking down of the yeast cell, due to stress, causing them to burst and release unwanted off-flavors into the beer.
Autolysis occurs when yeast sits under a lot of hydrostatic pressure, high alcohol, low acidity, and time.

 

“Secondary fermentation” is kind of an oxymoron.
Either you add more sugar to restart fermentation (such as bottling) or you are just letting fermentation finish out, right?
My first couple brews I went by the book but quickly found out that a) it’s unnecessary and b) yeast autolysis ruining beer is way overhyped if not an outright myth.

 

I secondary any beer that I'm saving the yeast cake on, especially if I am dry hopping. Not worried about e posture to air and since I have no way to cold crash, secondary allows and seems to clean up the beer better than leaving it in the primary.

 

I don't do a secondary for most beers, but autolysis is real. And it has ruined beers, so it's not an outright myth. It starts day 1. It's fairly uncommon to get the classic autolysis "burnt rubber" character, but that doesn't mean it's not affecting flavor in more subtle ways, like an increase in pH for example.

 

Another well-meaning post foiled by sloppy editing. Dead yeast release UNdesirable compounds in beer.

@Hoppsbabo -- you probably figured out my mistake by context. If not, sorry for the confusion

 

Interesting point. I'd believe this, but never heard anyone discuss subtle effects of autolysis before. Do you have more info, e.g., time frames that people think more subtle effects begin to show, what other subtle effects you might expect?

FWIW, I had burnt rubber once, in a commercial beer. Really unpleasant. It probably ranks among the worst of off-flavors, IMO. Mind you, I never cracked open a bottle of baby diaper.

 

He was a beauty. I saw him with his mate and a chick in the Monteverde Cloud Forest in Costa Rica. One of the coolest wildlife experiences I ever had and easily the best picture I've ever taken.

 

@Peter_Wolfe discussed this topic in a past thread:

“You'll start seeing low level autolysis after about 3 weeks, IF 1) you started with healthy yeast, and 2) the fermentation temp was kept low (68F or under the whole time). If you start with unhealthy yeast or heat stress it, it'll happen sooner. It takes 6-8 weeks to start seeing wholesale autolysis that gives off the soy sauce flavor if you never transfer off of primary. In a big dark beers (especially stouts), this flavor is pretty effectively masked until it gets really bad, but it shows up like crazy in pale ales.

As they autolyze, the yeast release enzymes, lipids, and metal cations that all have a negative effect on flavor.”

https://www.beeradvocate.com/commun...-too-long-in-the-primary.283588/#post-3572265

Cheers!