There is this constant discussion on a Dutch forum where it is claimed that it is good to rack beer to another vessel before the end of primary fermentation. Reasons: avoiding oxidation because fermentation with production of co2 will continue in the new vessel, and reduction of risk of autolysis because the beer gets off the yeast cake. Has anyone heard of this method, and does it have some validity? If not, are there any arguments why this could be harmful?
I’ve heard of people who do it, usually inadvertently or because they were told that it’s helpful. Often they are posting to ask why their fermentation has stalled. IME, the concerns about autolysis at the homebrew level are overblown. I regularly leave beer in primary for 4 weeks, sometimes longer, with no ill effect.
The greatest problem I see is that you’re pulling the beer off of the majority of the yeast before fermentation has completed. Thus, increasing the likelihood that the beer will stall or take a long time to reach final gravity. It’s better to let the yeast finish their job in primary. If you feel you must rack to a secondary, you can purge one with CO2 and rack after fermentation is complete.
Claim 1 is that people tend not to be able to recognize autolysis when it’s present. Claim 2 is that there remains enough yeast in the beer to finish fermentation.
The question is whether the yeast that has dropped to the bottom has become inert…
When I look at my un-stirred starter, there is a lot of CO2 being produced by the yeast on the bottom, so I would say it’s not inert.
If autolysis is there, and no one recognizes it, is it really there?
I suppose you can try it for yourself and see. I see no benefit to racking my beer to a secondary.
Autolysis does not happen that quickly unless there is a lot of pressure on the yeast. This is why commercial brewers worry about it and we don’t. We don’t have 100 barrels worth of beer pressure on a cylindrical cone of yeast.
Yes, there is still a lot of yeast in suspension, but in my brewing it has stalled fermentation when racked early.
Joe Sr. is correct.
If you take the beer off of the yeast before it has completed the job (IE fermentation and the re-absorbtion of fermentation by-products) you may risk things that will be worse than autolysis, such as diacetyl and acetylehyde (green apple flavors).
I agree with Joe, Jeff, and Frank. As for the first reason, ‘racking to avoid oxidation’ is absurd. Leave it in primary and avoiding oxidation is much more likely. And Jeffy is totally right about autolysis - our home fermenters are obviously a tiny fraction of the size of commercial fermenters, so the pressure placed on our yeast cells (and therefore the risk of autolysis) is a tiny fraction of that. I’ve left big beers (barleywine, quad, wee heavy, RIS) on the yeast for 2 months and never had any off flavors/aromas in the slightest. It’s basically a non-issue at home. This talk on the Dutch forum sounds like the same outdated, inferior advice that circulated to new brewers back when I started (and still turns up now and then in entry level kits and recipes).
Racking before completely fermented makes sense, if you have to rack to secondary. But it only makes sense in the way that if you are going to shoot yourself in the foot, you should do it close to the ER so you dont have to walk too far. Obviously the better decision would be to simply not shoot yourself in the foot.
Secondary fermentation is when you do a second fermentation, such as adding fruit or whatever. What most home brewers call “secondary” should really be called just a clean second fermenter. I have a hunch that this idea of racking beer off the yeast to another fermenter came from wine making… its old info. Its not the best approach. Propper brewing shouldn’t require multiple racking off beer from settled trub. In fact, if the yeast is still significantly in suspension, odds are its just not done yet.
Instead of “secondary fermenter”, it should be called “bright tank”, because that’s all that it is. If you feel the need to use a bright tank (i.e., to dry hop off of the yeast cake), then have at it. But for the vast majority of brews, you can safely go right from the fermenter to packaging without the added step.
The counterarguments are plain and simple: “we have no stalled fermentation, we have no diacetyl, we have no acetaldehyde.”
I think it can be done if managed properly. However, it is a step that can also cause problems if not. It is also a completely unnecessary step and looking to fix a problem that does not exist in the first place.
I have experienced autolysis before but never on homebrew batches that were kept on the primary yeast for up to 6 weeks after fermentation has been finished when kept cold. Simply not a problem.
I can tell you that for me, on 30 and 60 bbl batches, I get the beer clear in the fermentor first. Then rack clear beer over to the BBT to carbonate. Generally, once beer is in BBT it is only there for 24-72 hours. Of course, I do have the luxury of dumping yeast, but I still assert it is not necessary on 5-10 gallon batches. And I absolutely know for certain you can get crystal clear beer in the primary.
Then congratulate them and move on?
+1. If your friends are saying “we have no stalled fermentation, we have no diacetyl, we have no acetaldehyde”, it’s not because of the unnecessary transfer, it’s in spite of it. Transferring too soon can cause those things.
And I would ask why the extra work when I don’t have any of those issues leaving ALL of my beers in primary until packaging?
The problem is not so much that they do this, I couldn’t care less. The problem is that they recommend the method to other people, often newbies, who get confused by contradicting advice.
Tell your friends to split a batch, rack one before it’s done and leave the other until it finishes.
Set up some blind tasters and see what you think.
If something is working for people, they’re not generally open to change. Which makes sense. However, if there’s an easier or (arguably) better way of doing things, it’s worth checking out for yourself.
FWIW, I made a ton of beer with always racking to a secondary. I never had any problems that I was aware of at the time. If done carefully it shouldn’t cause problems. But not everyone has the same level of care.
It was somewhat tested but unfortunately not to minimum standards of objectivity that I would accept. So it’s quite hopeless 
There seems to be a percentage of people who, for whatever reason, cling to things they were taught, refuse to acknowledge any other way, attack people who don’t do it their way, and actively seek to convert others to their way.
I am now starting to formulate a hypothesis that when those people do not rack to secondary, their final beer simply is more yeasty: in another experiment a few people did a blind test with beers that were either racked during primary, or not racked, and the racked beers were perceived as cleaner, more fruity and less sulphury. Wouldn’t that be the expected perception of a more yeasty beer? So nothing to do with autolysis? And wouldn’t that imply that their clearing and bottling process is suboptimal?