[SeanFawcett]

I get very different opinions as to whether or not you should move the beer from the primary fermented into another carboy after the first week of fermentation.  Many books totally ignore the concept of a secondary fermentation. Some people have told me that a secondary robs the process from reaching full fermentation.  Others say not doing a secondary causes the dead yeast to encourage bad tastes.  But I've never seen a "pro-s and con's" analysis...

What's the general consensus here?

Why do a secondary?

How critical is it?

What's the down-side?

Does it depend on the type of beer?

Thanks for your input.

[flbrewer]

IMO, nope, not critical, down side is another vessel to own/clean and extra time until you can taste your beer.

Others may chime in on style, but there are many other ways to clean up a beer outside of secondary (cold crashing, finings, etc).

[Stevie]

Other downsides would be, another point of oxidation, another point of infection, stalled ferment if done to soon.

I only use a secondary if I want to add an addition that needs a lot of contact time or long aging. Oak cubes as an example.

Barley wines and other large beers are examples of where I will use a secondary 90% of the time. I often don't know when I will have time to bottle, so I will use a secondary vessel around 4 weeks or so for those large beers.

[brewday]

The only time I use a secondary is for aging sours.

[morticaixavier]

yeah, I'm pretty much with the others here. I'll age a beer in a different container than the fermenter. I actually have one recipe that I do move to secondary, my sour farmhouse ale is moved after 6 days and has dregs pitched in although I'm not sure how much that really does in terms of 'feeding the bugs'

[majorvices]

I age high gravity beers in corny kegs. I will age some funky sour beers in glass carboys. Other than that everything I homebrew goes from fermentor to keg. Sometimes I treat the keg like a bright tank and rack from the keg to another keg via jumper tubing and co2.

If you are going to use a secondary, make sure you purge with co2 first. Otherwise you are doing more harm than good.

[HoosierBrew]

I use a secondary on fruit beers or big beers,ie., beers that need to sit in a fermenter (not on the yeast cake) for extended periods. Other than that there is just nothing gained and, as mentioned, potentially negative things from using a secondary.

[S. cerevisiae]

I am the odd man out here because I use a secondary for almost every batch.  Most of my beers sit five to six weeks before they are kegged.  There's no way that I am letting a beer sit on the lees for that long.  One does not have worry about the yeast breaking down as much as one has to worry about the break and hop material adding a harsh edge to the beer.

I am also of the school that oxidation is not a major problem when racking to a secondary because yeast cells are still in suspension.  Any O2 that is introduced during racking will be rapidly scrubbed from the green beer by suspended yeast cells. Charlie Bamforth concurs with this assessment. The time to seriously worry about cold side oxidation is after beer has been filtered.  That doesn't mean that brewers can go crazy when racking.  It just means that there are greater sources of oxidation than racking, like not using a length of tubing on one's mash tun ball valve and allowing one's runoff ro shoot out of the valve like water from a fire hydrant.  That's a recipe for trans-2-nonenal precursor production because lipoxygenase is still active.

[majorvices]

I am the odd man out here because I use a secondary for almost every batch.  Most of my beers sit five to six weeks before they are kegged.  There's no way that I am letting a beer sit on the lees for that long.  One does not have worry about the yeast breaking down as much as one has to worry about the break and hop material adding a harsh edge to the beer.

I am also of the school that oxidation is not a major problem when racking to a secondary because yeast cells are still in suspension.  Any O2 that is introduced during racking will be rapidly scrubbed from the green beer by suspended yeast cells. Charlie Bamforth concurs with this assessment. The time to seriously worry about cold side oxidation is after beer has been filtered.  That doesn't mean that brewers can go crazy when racking.  It just means that there are greater sources of oxidation than racking, like not using a length of tubing on one's mash tun ball valve and allowing one's runoff ro shoot out of the valve like water from a fire hydrant.  That's a recipe for trans-2-nonenal precursor production because lipoxygenase is still active.

There is some truth to this but it is not fool proof. I bottle a lot of beer and I do not filter and even after bottle conditioning I have picked up signs of oxidation on beers that were not handled properly after a fairly short time. Also, my understanding is that oxidation that happens to the hops happens quicker than it takes for the yeast to metabolize the oxygen.

[denny]

I get very different opinions as to whether or not you should move the beer from the primary fermented into another carboy after the first week of fermentation.  Many books totally ignore the concept of a secondary fermentation. Some people have told me that a secondary robs the process from reaching full fermentation.  Others say not doing a secondary causes the dead yeast to encourage bad tastes.  But I've never seen a "pro-s and con's" analysis...

What's the general consensus here?

Why do a secondary?

How critical is it?

What's the down-side?

Does it depend on the type of beer?

Thanks for your input.

John Palmer answers that question in this very forum.  In short, he says that he, Jamil, Wyeast, and white Labs all recommend no secondary 99% of the time....https://www.homebrewersassociation.org/forum/index.php?topic=15108.msg191642#msg191642

[S. cerevisiae]

The post-fermentation O2 staling claim in John's post was debunked by by N. Hashimoto in 1974.  John's new claim is yet another example of a new home brewer myth replacing an older home brewing myth.

Much of Charlie Bamforth's research has been in the area beer staling.  Charlie explains why the introduction of O2 while yeast is still in suspension is not a problem starting at time 24:45 in the video linked below.  He also supports what I said about O2 not being a major problem until the yeast cells are filtered from the beer.

https://www.youtube.com/watch?v=Fm2t_5HrMcc

In the end, the choice to use a secondary or not is up to the brewer and his/her brewing capacity/schedule.  However, the staling argument for not racking is a non-sequitur.  Staling is not a major problem while yeast cells are still in suspension.

[narcout]

I am also of the school that oxidation is not a major problem when racking to a secondary because yeast cells are still in suspension.

Would this be true even if the beer was chilled into the low 30's for a day or two prior to racking? 

I know yeast cells would still be in suspension, but would they scrub oxygen at that temperature or would they be too dormant?

[majorvices]

The post-fermentation O2 staling claim in John's post was debunked by by N. Hashimoto in 1974.  John's new claim is yet another example of a new home brewer myth replacing an older home brewing myth.

Much of Charlie Bamforth's research has been in the area beer staling.  Charlie explains why the introduction of O2 while yeast is still in suspension is not a problem starting at time 24:45 in the video linked below.  He also supports what I said about O2 not being a major problem until the yeast cells are filtered from the beer.

https://www.youtube.com/watch?v=Fm2t_5HrMcc

In the end, the choice to use a secondary or not is up to the brewer and his/her brewing capacity/schedule.  However, the staling argument for not racking is a non-sequitur.  Staling is not a major problem while yeast cells are still in suspension.

That's all well and fine but it doesn't explain why oxidation has occurred in my personal experience.  If the assertion were true you'd think unfiltered beer wouldn't oxidize but it does. I've had unfiltered hoppy ales get mishandled and the hop oils have oxidized in a very, very short time. Also, narcout brings up an excellent point. How does yeast metabolize the o2 if they are otherwise dormant?

[HoosierBrew]

That's all well and fine but it doesn't explain why oxidation has occurred in my personal experience.  If the assertion were true you'd think unfiltered beer wouldn't oxidize but it does. I've had unfiltered hoppy ales get mishandled and the hop oils have oxidized in a very, very short time. Also, narcout brings up an excellent point. How does yeast metabolize the o2 if they are otherwise dormant?

+1.  I've had many hoppy beers that didn't stale to the point of cardboard, wet dog aromas but the hop oils oxidized very quickly, scrubbing away most of the aroma after sloppy racking. There is a reason that basically every hoppy beer guru (Steele, Cilurzo, etc.) preaches to homebrewers fanatically  (Mitch did it here on "Ask the Experts') about reducing exposure to oxygen post fermentation, racking to purged kegs, etc., to preserve hop character.  I'm pretty sure these guys understand that homebrewers are not filtering their beers. My personal observation in this area means more to me than anybody's theoretical info to the contrary.

[S. cerevisiae]

Also, narcout brings up an excellent point. How does yeast metabolize the o2 if they are otherwise dormant?

The better question is why would anyone rack to a secondary after cold crashing?  What is gained by cold crashing before racking to a secondary?  Cold crashing artificially ends the fermentation cycle.

One of the big reasons why I still use a secondary is that it allows me to crop higher quality yeast.  The yeast cells that are still in suspension at racking time are the least flocculent cells, some of which may be petite mutants.  Carrying these cells over to the next fermentation can have a negative effect on fermentation.