Question on shaking carboy

There's never a time during fermentation that there is no O2 in the headspace. And shaking will definitely increase the O2's migration into the wort/beer. This doesn't necessarily mean your beer is ruined, but I wouldn't shake in the future.

 

I put stainless steel ball bearings in my hop sack to sink it. Shaking not good!

 

Your beer will be okay. You didn't shake it that hard, and there isn't too much O2 in the headspace. This being a hoppy beer, you're going to drink it quickly anyway (it will be a tasty beer, so don't hold back), so if oxidation is going to occur as a result of the shaking, it will be so slow and minimal that you'll probably never notice it.

 

Ideally, you use a paint mixer paddle attachment (well sanitized) on your driller to stir up your fermenter and integrate any flavors without incorporating too much O2. As long as your ferment is still active, the stirring from the bottom will offgas CO2 and protect your beer from air.

 

Why did you shake a beer with an FG of 1014?. It is a fairly normal beer FG. . What was your mash temps schedule?. what was your OG?. What was your yeast?.

 

I'm not buying it. Stirring pushes CO2 out of the fermenter. Offgassing will always pull air into a fermenter. There are ways to purge with CO2 tanks. Oxygen is still a variable here.

 

@Fish365 1.014 might be a reasonable FG for your beer. With your recipe, yeast, and mash temp, and OG we could tell if that's to be expected.

 

I think he was shaking his fermenter to get the dry hops saturated in the beer?

The less shaking the better from what I've read and seen

 

Sometimes I'll just tip my carboy to get the hops down. Usually works for me. Try not to shake your beer.

 

I use carboys as fermenters and getting the bag out is annoying so usually dry hop in the keg and use a SS fitting (typically a coupler) to help submerge the bag. I use corny lids with a welded tab that I tie the fishing line to. I usually dry hop with hole hop hops and fluff the cones in a baggy filled with CO2. after filling the hop bag, I purge it as it well as possible with CO2 before dropping in the keg. Then I purge the headspace.

 

Obviously, some oxygen is getting in the fermenter, which is not the end of the world (considering you need some oxygen to finish off a beer). My point was that using a paddle mixer integrates the least oxygen while still homogenizing the yeast cake throughout the solution, and allowing the dry hop bag to get submerged into the wort. Rolling your tanks is a common practice in commercial brewing and winemaking. On a professional level Guth agitators are used to stir tanks while minimally aerating your wort (http://www.scottlab.com/uploads/documents/technical-documents/11/GuthBrochure.pdf).

In my experience, accelerating fermentation via gentle aeration is far better than letting a primary run on too long. And, if you're worried about integration of O2, simply purge your headspace before and after stirring with CO2.

 

Some O2 is needed by the yeast to build cell walls (allowing adequate propagation) before fermentation. No O2 is needed to "finish" a beer.

I dunno about wine, but this isn't common in commercial brewing.

 

This is good practice with wine.

 

Winemaking is definitely where I learned this practice of rousing the yeast to reinvigorate stuck ferments. I know that a little bit of air intake is not ideal, but in my experience it also helps beers to finish off properly when I have had idle ferments. Rousing the yeast back into suspension can facilitate dormant yeast cells back into action that have been buried or compacted in the cake. Why wouldn't you do this with a beer?

 

Beer isn't like wine in this way. Wine, from my understanding, holds up better to oxidation. It might be the ABV, and it be some difference between fruit and malt. A little oxidation is acceptable in some styles of beer. This is usually very subtle, and usually because of aging.

See wood aged beer:

http://www.bjcp.org/2008styles/style22.php

 

After the yeast have finished multiplying, additional oxygen does not help the beer "finish off properly." I don't doubt that rousing your yeast has been helpful at times (though 99% of the time, it shouldn't be necessary), but it wasn't because of the added O2.

People do rouse the yeast sometimes, to try to unstick a fermentation. But usually not by violent shaking, and not by using a paddle mixer, which will suck in O2. O2 is generally bad for beer.

 

VikeMan, I understand that O2 is, on the whole, bad for beer after fermentation has begun. My point is that a paddle mixer is the most minimally oxidative way to rouse the yeast, especially when conducted with a CO2 buffer (I use a line coming off my regulator with a T on the end hanging in my carboy and the PSI set to about 7 PSI while I stir).

This is only for stuck ferments, not for ideal scenarios. Obviously, any incorporation of O2 is potentially hazardous. But when I've had the choice between a half finished beer and potential contamination I've always chosen the latter and will continue to do so, especially in lew of shaking the carboy.

 

*Gentle* rocking of a closed fermenter rouses the yeast, causes very little surface agitation, and introduces no new o2 into the headspace. The yeast does not need to be manually forced to be homogeneously distributed throughout the wort.

CO2 injection while paddling? You're making that up, right? If not, it's Rube Goldberg and not necessary.

 

I've had a few beers get stuck (london ale yeast 1968 done this to me 2 times), it flocked out before it was done. In the past I have swirled the carboy (with airlock on the whole time) there was no air flow into the carboy, just out of.

That said, since then, in order to get this yeast to behave and not crap out, I finish fermentation warmer just after it slows down. I stick a heat wrap on the carboy with a temperature controller and hold at 74 degrees F. That works better, and rousing yeast is a pita, better to prevent then try to resolve.

(In general I tend to ferment cool, so this is not going to be everyone's problem, and 1968 sure doesn't like my ambient temp of 60 after it's done with the vigorous phase).

So, gentle swirl fine. but try to prevent this problem by picking a lower flocking yeast or one that works at cooler temps, or raise the temp and control better going into the future.