What does a secondary fermenter do?

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renstyle

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There are alot of ways folks can clarify their brews these days. From inline 1-micron kits that you can pick up for less than $40 shipped from many sources all the way to a secondary transfer and good ol' time and temp...with gelatin, isinglass and untold other options in between.

The malt the vast majority of us use these days has a higher percentage of fermentable sugars than barley from decades ago. Doesn't stop folks from doing decoctions tho (well it does stop most of us) ;)

The best takeaway is that the greater number of options on multiple fronts allows all of us to take our version of the hobby as far as we need to go.

In the past, with the material available at the time, a secondary was likely necessary to have a decently clear beer with a reasonable turnaround time, with notes added during maturation, however short. It's likely not necessary now. But "necessity" is always in the eye of the beholder when it comes to fermentation. :D
 

jerrylotto

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I also use a conical and no secondary. The advantage of course is that you can remove whatever you want (trub, yeast cake, any other small items that don't float) from the bottom, without introducing oxygen. I have the7 gal Fermzilla and love it. Another thing that I changed is that I do closed loop transfers to a keg, even when I intend to bottle. If bottles are in the plan, I add the priming sugar to the keg before purging O2, and then put 2-3 psi on it and cold crash. The liquid side goes to my bottling wand and the bottles are all pre-purged with CO2 after cleaning, covered with plastic wrap and a rubber band, and in a large plastic garbage bag that I use like a poor man's glove box. Needless to say, I only bottle a few - most of my beer stays in the keg :)
 

BrewnWKopperKat

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follow-up to ...
I'm actually kind of amazed that the kit-makers are still including a secondary in their instructions.
I scanned "top extract kit" instructions from a couple of online homebrew stores recently (early March 2021).

At least one store does not mention secondary in their online instructions (maybe they never did).

Another was "almost" secondary free - could it be that someone missed updating a PDF?
 

Brews and Blues

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I also use a conical and no secondary. The advantage of course is that you can remove whatever you want (trub, yeast cake, any other small items that don't float) from the bottom, without introducing oxygen. I have the7 gal Fermzilla and love it. Another thing that I changed is that I do closed loop transfers to a keg, even when I intend to bottle. If bottles are in the plan, I add the priming sugar to the keg before purging O2, and then put 2-3 psi on it and cold crash. The liquid side goes to my bottling wand and the bottles are all pre-purged with CO2 after cleaning, covered with plastic wrap and a rubber band, and in a large plastic garbage bag that I use like a poor man's glove box. Needless to say, I only bottle a few - most of my beer stays in the keg :)
I want that exact Fermzilla. I have watched a bunch of videos on it an I'm convinced. I even like how if you use the collection jar to dry hop, you can purge the oxygen out of that with the side ports. That thing just seems super easy and convenient. I may not make the jump right away, but I think that is my next purchase. Glad to hear you like it
 

Birrofilo

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The not small problem with the Fermzilla is that little nasty writing which they put on it, and which says that you should not use it past 2 (or 3, I go by memory) years from production date, which is also written.

I don't think that it goes into pieces or it explodes after 2 years and 1 day from production, but the idea of buying something of that kind with an expiry date written on it is something that sends a shiver along my spine.
 

Brews and Blues

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The not small problem with the Fermzilla is that little nasty writing which they put on it, and which says that you should not use it past 2 (or 3, I go by memory) years from production date, which is also written.

I don't think that it goes into pieces or it explodes after 2 years and 1 day from production, but the idea of buying something of that kind with an expiry date written on it is something that sends a shiver along my spine.
Really? Is that because it is plastic and not stainless? That would be a tough pill to swallow to spend $200 on one with all of the accessories and then have to replace it in 2 years.
I'm just using plastic buckets right now. Should i change those out after a while too? They are cheap enough to replace every year or two if need be.
 

Birrofilo

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Really? Is that because it is plastic and not stainless? That would be a tough pill to swallow to spend $200 on one with all of the accessories and then have to replace it in 2 years.
I'm just using plastic buckets right now. Should i change those out after a while too? They are cheap enough to replace every year or two if need be.
Yes, really.
I think this is because they should withstand pressure, and the producer doesn't want to have financial or other kind of trouble if the products begin failing serially. Recently they enlarged the opening which naturally makes the entire build less robust.

I think it's an ass-saving writing from their part. The fermenter is probably much more robust than that, but you know, if there is a problem, your problem. If you want to stay perfectly safe you can replace only the fermenter (not the accessories) but, again, those can be out of production in a few years.

If and when I get into this pressure thing, I think I will buy SS, it's more expensive but it's literally forever. I don't like replacing.
 

VikeMan

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The Fermzilla manual says "If you use the fermenter under pressure hydro test the fermenter every 24months to ensure it is safe to use." <italics mine>
 

Birrofilo

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The Fermzilla manual says "If you use the fermenter under pressure hydro test the fermenter every 24months to ensure it is safe to use." <italics mine>
That would be certainly different. Somebody should tell us the exact writing on the fermenter. I saw a YouTube video where the writing was "not to be used beyond month/year with pressure applied" or something to that effect, if memory serves. That killed my interest in the product.

How can one make this hydro test?

Yes, it was "Test container or do not use under pressure" 8:39 then the person talks about replacing the stuff and that is what remained in my memory. It would be interesting to know how complicated is the test.
 
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Brews and Blues

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Just reading reviews on a lot of these products, it seems like you get what you pay for. Buy plastic and receive plastic and realize that one day something is probably going to break.
 

Birrofilo

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Actually, going by memory which I see is defective 😲, I remember having read in some Italian forum of some people using the normal plastic fermenters with pressure, because any plastic fermenter can withstand some pressure. If 0,3 bar or less (5 PSI or less) is what is needed for pressure transfer it is entirely possible that one can pressure transfer from any fermenter, after applying the required holes and valves etc.

Carbonating is different because it requires 1 - 1,4 bar and requires something more specific.
 

HVCBrewing

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Secondary vs not I - I haven’t observed a difference. I’m relatively new and can’t offer a scientific analysis. I am under the impression (possibly wrong - appreciate any input here) that oxidation is delayed/minimized when the CO2 from the final stages of fermentation are retained. If I ferment a beer and cap the carboy/conical at the end of fermentation (Spunding valve at say 5 psi or cap the carboy at the very end of fermentation) vs allow the CO2 to outgas through an airlock, the CO2 is retained and oxidation is minimized. The application would be to finish the ferment under pressure vs airlock. Let the beer settle under pressure vs airlock. Then if moved to secondary, the retained CO2 would minimize any oxidation risk. Thoughts?
 

VikeMan

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Then if moved to secondary, the retained CO2 would minimize any oxidation risk. Thoughts?
Off-gassing CO2 would bounce a little bit of O2 away, but "minimize" would be wishful thinking. The way to minimize CO2 is to not do an open transfer.
 

DavidWood2115

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I have a (modestly) contrarian opinion about secondaries; namely, I do a secondary to *reduce* oxygen exposure. Let me explain.

Like many(?), I learned to do primary fermentation in plastic buckets, secondary in glass carboys, and (originally bottle, but now) keg my beer. After a disastrous first attempt at a hazy IPA last summer (yes, major oxidation) I decided to get serious about doing semi-closed transfers between primary and secondary and between secondary and keg. After a number of less than successful combinations I have settled on the following process.
1. Do primary fermentation in my (otherwise now unused) bottling bucket. The lid seems to have a seal that is somewhat less tight than my fermentation buckets, but those don't have perfect seals either and the bottling bucket has a spigot.
2. After 5-7 days, do a full starsan/CO2 purge of a glass carboy, then do a pressure-assisted gravity transfer. Connect the hose just sanitized during the CO2 purge to the primary's spigot and connect the CO2 line to the airlock/blowoff hole in the primary, setting the regulator to ~2psi of CO2. The CO2 keeps O2 from filling the primary headspace and modestly accelerates the transfer (but will blow the top off the bucket if you turn the pressure too high!). Add dry hops, as needed (should be the only direct O2 exposure). Ferment in secondary 1-4 weeks.
3. (optionally) Cold crash in keezer, replacing the airlock with a mylar balloon filled with CO2 to reduce/eliminate O2 suck back.
4. When ready for kegging, do a full starsan/CO2 purge of a corny, then do a pressure-assisted gravity transfer from secondary under ~2psi of CO2.

This process requires a bit more equipment and futzing than an autosiphon, but introduces far less O2. And I am pretty sure that I reduce the O2 exposure of my beer compared to leaving it in primary, since the carboy is much less O2 permeable than the bottling bucket (or even a standard fermentation bucket). All of my IPAs, hazy or not, have much better hop flavors since I started doing semi-closed transfers.

The only real problem I have had with this process is independent of whether I use a secondary. Namely, when I do a closed transfer to the keg, if the beer has any dry hops (which many of my beers do) I occasionally clog up the liquid QD and have to stop/disassemble/clean/resanitize the QD and liquid post to clear the clog, which introduces some modest amount of O2 during the transfer.
 

Birrofilo

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@DavidWood2115

It seems that your reason to do a secondary transfer is that your secondary fermenter is in glass and therefore substantially exempt from air permeability, while your primary fermenter is in plastic and that is somehow less ideally gas-permeable for a 4-5 week fermentation.

If that's the case, I suggest you have a look at large-mouth glass demi-jones with plastic protections. They are in glass, they can be cleaned just like a plastic bucket, and you would avoid a transfer. And they have that nice plastic wrap which makes them so less dangerous than the naked glass carboys I see on sale in the US.


You can also find them with a tap

 

PianoMan

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Poor OP...just asked a question. This might have been said somewhere but instead of transferring to secondary, add the secondary hops to primary fermenter at day 3 of visible signs of fermentation. I used to secondary DIPAs but the flavor would only last 3 weeks because of the oxidation issue mentioned.
 

orionol73

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Yes, though technically I'm doing the tests to see if no-secondary improves my beer vs doing a secondary. If it doesn't, I'll probably go back to using the secondary because I'm used to the process. What I'm trying to find out is if the oxygen I introduce in doing a secondary makes any difference to me.

BTW: I think it's cute that someone thinks I could do a cold crash. My temperature control is my basement. One time during a very cold spell some years ago I did move the fermentation pail to the side of the basement with the furnace and hot water heater. Worked like a charm BTW.
It is cute that anyone on this forum would have the interest to try and share experiences and ideas with you to help you figure out your own best practices
brew on...
 

D.B.Moody

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I'm sorry, @orionol73. I didn't mean it that way. I meant that I am no where advanced enough in my methods to do that type of thing. I meant it in a self depreciating manner, as a joke about me.
 
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