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…
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.
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’
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.
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.
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.
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.
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?
+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.
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.
After primary fermentation is complete, I cold crash for a few days and then rack into the serving keg which goes into the kegerator for cold conditioning and carbonating.
What I was wondering was whether the yeast would still scrub any oxygen that was introduced at that point. I rack under pressure into CO2 purged kegs so it isn’t much of an issue for me. I was just curious.
I have experienced exactly this problem with the least flocculent cells. I have found that after a few generations of harvested yeast, I sometimes wind up with batches that will not clear.
My SOP on harvesting is to swirl up the yeast from the primary and pour into sanitized containers.
No big deal, as they clear with time and gelatin, but sort of PITA. It lets me know when to get some fresh yeast.
That’s a major drawback of not being able to draw from the middle layer from a conical when repitching.
Racking can be used to select for flocculaton characteristics. For example, one can end up with a crop that is more flocculent on average than the original yeast culture by racking early. If one keeps racking early and cropping from the primary, one can often make the culture progressively more flocculent. The transformation may not happen in a batch or two, but it will happen because one is cropping the most flocculent cells when one racks early and crops from the primary.
If you have the opportunity to watch a top-cropping brewery in action, you will see that they usually skim and discard the first head, which is known as the “brown head.” The second yeast head is skimmed and used to pitch the next batch.
Yes. AFter some serious non-flocculant selection after sequential cropping I’ve changed to taking one big crop (2nd gen) and using that to build starters for subsequent batches. So far, better luck.
But, if you collect yeast in mason jars and shake the jar you should be able to scrape the top layer and get to the middle. Maybe this isn’t perfect but it is what I have used in the past with great success. And I usually cold crash on the yeast cake and I can’t say I have ever had any problems with this method. That said, I have never gone more than 3 or 4 gens with carboy/bucket yeast harvesting.
Using conicals, it is very nice to be able to select yeast from the middle layer with racking arm.
Mark: If oxidation is not a problem on un filtered beers why is it that on our bottling line at YHB the beers that come off the line mis-capped are set aside and hand capped later and reserved for brewery consumption. And after about 2 weeks there is a definite flavor loss in the mis-capped ones as opposed to the capped ones. I can’t understand why this would have any other explanation except that is is oxidation. And this is on a wheat beer with plenty of live yeast in suspension. If having live yeast in suspension was a silver bullet as you assert, you would think that those beers would be just as fresh as the others that are capped on foam a half second later.
All that said, I used to rack my homebrew into unpurged corny kegs before I “knew better” and back then I can’t really say I experienced any major problems. I would be really careful on the racking though and purge the head space immediately afterward. If you have a lot of co2 still dissolved in the beer and you rack really careful the co2 coming out of solution should displace the o2 in the head space. But, still, I think it is far better to just purge. After handling hundreds of kegs and thousands of gallons of beer at a working brewing I can truly attest to how important it is to minimize o2 pick up post fermentation at every level. Because, infection aside, oxidation is the number one factor in beer freshness - hands down - even on unfiltered beer. I do believe that yeast in suspension helps to mitigate oxidation, but I do not believe that is is a magic bullet.