Though you don't technically need to transfer to a secondary to make beer, your brew will benefit immensely if you siphon it into a second container to ferment, making sure not to include the trub that collects at the bottom. This not only improves clarity, but will generally get rid of a number of flavors that taste like dirt and badness.
.
Actually you will find that many many many of us believe exactly the opposite, that prolonged yeast contact
IN PRIMARY makes for better tasting beer, because rather than the yeast beging the cause of off flavors, prolonged yeast contact actually ALLOWS the yeast to clean up after itself. And it does it more efficiently in primary.
The idea that yeast/trub leads to off flavors is oldschool thinking that has been disproved over the last 5 years or so.
Even the person most responsible for perpetuating that old idea (John Palmer) has admitted HE was operating under one of those "common beliefs" that we all used to believe hands down.
Most of us realize now, that fermenting the beer is just a part of what the yeast do. If you leave the beer alone, they will go back and clean up the byproducts of fermentation that often lead to off flavors. That's why many brewers skip secondary and leave our beers alone in primary for a month. It leaves plenty of time for the yeast to ferment, clean up after themselves and then fall out, leveing our beers crystal clear, with a tight yeast cake.
Diacetyl is one of those things cleaned up simply by long yeast in primary contact. You can read that info here
https://www.homebrewtalk.com/f13/pr...d-butter-please-70438/index2.html#post1080693
Maturation of beer flavour requires the presence of yeast as a catalyst. There are many methods of finishing that have the sole objective of prolonging the contact of beer with yeast after primary fermentation is completed....
Method 1
If a very cold primary fermentation was used it involves allowing the beer temperature to rise from the controlled primary fermentation temperature of about 10°C to 15-18°C when the primary fermentation is coming to an end. Normally, the time is determined by the attenuation of the beer. If, for example the wort starting gravity was 1050 and the expected terminal gravity is 1010, then the diacetyl rest would be commenced when the beer has attenuated to about SG 1023 when two-thirds of the total fermentable material in the wort has been consumed. The diacetyl rest normally lasts for 48-72 hours, until primary fermentation is over and secondary fermentation is under way. At this time the temperature is lowered when the more traditional method is followed, probably 1°C per day until the lagering temperature of 0-1°C is reached.
Method 2
If a warmer primary fermentation temperature was used for ale or lager the diacetyl rest involves either lowering the beer temperature 2 or 3°C at the end of primary fermentation or keeping it constant for up to 6 days. In lager yeast strains with low diacetyl production it is common practise nowadays to employ a short diacetyl rest followed by centrifuging to remove excess yeast and then crash cooling to 0°C. When brewing ales, that should have very low diacetyl levels especially German Ales like Alt and Kölsch, the implications are to not use highly flocculent yeast and to allow an extended primary fermentation, albeit at cooler temperatures until sufficiently low diacetyl levels are reached. Yeast that settles in the cone is still removed on a daily basis.
We have multiple threads about this all over the place, like this one
https://www.homebrewtalk.com/f39/ignore-instructions-do-not-bottle-after-5-10-days-78298/
If you leave the beer alone, they will go back and clean up the byproducts of fermentation that often lead to off flavors. That's why many brewers skip secondary and leave our beers alone in primary for a month. It leaves plenty of time for the yeast to ferment, clean up after themselves and then fall out, leveing our beers crystal clear, with a tight yeast cake.
This is the latest recommendation, it is the same one many of us have been giving for several years on here.
John Palmer said:
Tom from Michigan asks:
I have a few questions about secondary fermentations. I've read both pros and cons for 2nd fermentations and it is driving me crazy what to do. One, are they necessary for lower Gravity beers?
Two, what is the dividing line between low gravity and high gravity beers? Is it 1.060 and higher?
Three, I have an American Brown Ale in the primary right now, a SG of 1.058, Should I secondary ferment this or not?
Your advice is appreciated, thanks for all you do!
Allen from New York asks:
John, please talk about why or why not you would NOT use a secondary fermenter (bright tank?) and why or why not a primary only fermentation is a good idea. In other words, give some clarification or reason why primary only is fine, versus the old theory of primary then secondary normal gravity ale fermentations.
Palmer answers:
These are good questions – When and why would you need to use a secondary fermenter? First some background – I used to recommend racking a beer to a secondary fermenter. My recommendation was based on the premise that (20 years ago) larger (higher gravity) beers took longer to ferment completely, and that getting the beer off the yeast reduced the risk of yeast autolysis (ie., meaty or rubbery off-flavors) and it allowed more time for flocculation and clarification, reducing the amount of yeast and trub carryover to the bottle. Twenty years ago, a homebrewed beer typically had better flavor, or perhaps less risk of off-flavors, if it was racked off the trub and clarified before bottling. Today that is not the case.
The risk inherent to any beer transfer, whether it is fermenter-to-fermenter or fermenter-to-bottles, is oxidation and staling. Any oxygen exposure after fermentation will lead to staling, and the more exposure, and the warmer the storage temperature, the faster the beer will go stale.
Racking to a secondary fermenter used to be recommended because staling was simply a fact of life – like death and taxes. But the risk of autolysis was real and worth avoiding – like cholera. In other words, you know you are going to die eventually, but death by cholera is worth avoiding.
But then modern medicine appeared, or in our case, better yeast and better yeast-handling information. Suddenly, death by autolysis is rare for a beer because of two factors: the freshness and health of the yeast being pitched has drastically improved, and proper pitching rates are better understood. The yeast no longer drop dead and burst like Mr. Creosote from Monty Python’s The Meaning of Life when fermentation is complete – they are able to hibernate and wait for the next fermentation to come around. The beer has time to clarify in the primary fermenter without generating off-flavors. With autolysis no longer a concern, staling becomes the main problem. The shelf life of a beer can be greatly enhanced by avoiding oxygen exposure and storing the beer cold (after it has had time to carbonate).
Therefore I, and Jamil and White Labs and Wyeast Labs, do not recommend racking to a secondary fermenter for ANY ale, except when conducting an actual second fermentation, such as adding fruit or souring. Racking to prevent autolysis is not necessary, and therefore the risk of oxidation is completely avoidable. Even lagers do not require racking to a second fermenter before lagering. With the right pitching rate, using fresh healthy yeast, and proper aeration of the wort prior to pitching, the fermentation of the beer will be complete within 3-8 days (bigger = longer). This time period includes the secondary or conditioning phase of fermentation when the yeast clean up acetaldehyde and diacetyl. The real purpose of lagering a beer is to use the colder temperatures to encourage the yeast to flocculate and promote the precipitation and sedimentation of microparticles and haze.
So, the new rule of thumb: don’t rack a beer to a secondary, ever, unless you are going to conduct a secondary fermentation.
THIS is where the latest discussion and all your questions answered.
https://www.homebrewtalk.com/f163/secondary-not-john-palmer-jamil-zainasheff-weigh-176837/
We basically proved that old theory wrong on here 5 years ago, and now the rest fo the brewing community is catching up. Though a lot of old dogs don't tend to follow the latest news, and perpetuate the old stuff.
The autolysis from prolong yeast contact has fallen by the wayside, in fact yeast contact is now seen as a good thing.
All my beers sit a minimum of 1 month in the primary. And I recently bottled a beer that sat in primary for 5.5 months with no ill effects.....
You'll find that more and more recipes these days do not advocate moving to a secondary at all, but mention primary for a month, which is starting to reflect the shift in brewing culture that has occurred in the last 4 years, MOSTLY because of many of us on here, skipping secondary, opting for longer primaries, and writing about it. Recipes in BYO have begun stating that in their magazine. I remember the "scandal" it caused i the letters to the editor's section a month later, it was just like how it was here when we began discussing it, except a lot more civil than it was here. But after the Byo/Basic brewing experiment, they started reflecting it in their recipes.
Most of us will now say that our beers taste and look better for having left it in primary for a month.