Shaking the Carboy....

Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum

Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

h4rdluck

Well-Known Member
Joined
Jun 21, 2009
Messages
117
Reaction score
10
Location
blacksburg, va
So im pretty confused on this whole thing...

My first batch i pitched with whitelabs did not have a krauzen after 2 days. So i did what everyone said not to do and I shook the F' out of it (I had done so after the wort chilled originally also). Almost immediately there was krauzen, and it was fermenting non stop for 3 days. This batch came out awesome.

My next 2 batches I actually repitched half and half from my yeast cake from my original carboy. This amounted to about 2x12oz bottles of trub and yeast cake (That i stored as is in the fridge for about 2 weeks) that I was able to pitch into each carboy from the original yeast cake. This i all aerated the same and fermentation commenced within hours.

My fourth batch i decided to use a new yeast strain. so i bought another white labs vial. I aerated the f' out of my wort after chilling and pitched. Again. Same problem as the first batch. Its been 2 days with absolutely no krauzen and no activity. So i just shook the **** out of it and now its got krauzen and is going like mad...

So i believe my problem is more that im not making a yeast starter...and not pitching enough yeast. Fine.. im prepared to goto the next level in my beer making skills :)

But my real question is... Why is shaking the wort after pitching the yeast considered a taboo thing to do? I have read all kinds of thought about it. Some say its ok within the first few weeks. Some say never! No! how could you! you will impart aweful flavors!

I have a friend who makes very high gravity beers. worts with sg of 1.2 , 1.3 sometimes higher...

He said rather than buying an air pump and stone and the like, he just shakes the crap out of his carboy almost everyday for 2 weeks for his high gravity beers....

So whats the deal? Ive drank many beers of his and his been brewing mass quantities for years and hes got no problems with shaking and his beers is fantastic.

Penny for your thoughts here for sure.

Thanks

-+-
 
The problem with shaking is that there is a chance (albeit small) that you would introduce oxidation off flavors.

There is less of a problem before or shortly after fermentation begins, because before fermentation, you want as much oxygen as possible in the wort for the yeast, and during fermentation there is so much C02 being produced that the chances for oxygen being introduced are slim. High gravity beers need a lot more out of the yeast then regular gravity beers, so it is sometimes recommend to re-aerate them after a couple days to help ensure you get as much attenuation of the yeast as possible.

That being said, i'm sure if you just waited another day or 2, you would have seen signs of fermentation regardless of whether or not you shook your carboy. In the past i've shaken the hell out of beers in the secondary trying to get dry hops to submerge and i haven't noticed any oxidation flavors yet, but YMMV.
 
I would just think that with my friends experience of shaking for 10 minutes each day for 2 weeks of a high gravity beer that the chance of off flavors would definately have arisen in his beers and they haven't...

and you are right...there very well may have been signs of fermentation in another day or two...but if i can kick start the fermentation...why would i not want to?
 
If you shook it and there was krauzen almost immedietly, then most likely fermentation had started and you were just making suspended CO2 bubbles come to the surface. Next time, try stirring gently with a sanitized spoon. You don't have nearly the risk of introducing oxidation into the beer.
 
right but im still not sold on this oxidation of the beer. There was zero krauzen to begin with... When i shook it at first it was just typical foamy quality like when you aerate your wort to begin with. But then within about 2 hours it starts to change into the bubbling type of foam. So While i am convinced that fermentation WAS beggining...after 2 days I like to see more progress than that. As does my friend.

I am curious about this oxidation issue. Everyone talks about it and warns of it. But as far as what i have seen how much of a risk is this really? I've even read a site (sorry i'd have to search back alot) that stated for the home brewer who shakes his wort there is practically no risk of oxidizing your wort because we could not hope to get enough oxygen in there just by shaking...

Now i am playing devils advocate a little, but I have been unable to really come up with a lot of answers on this subject. Lots of cautions and warnings, but no actual answers.
 
As you mentioned, just make a starter next time. I always use WhiteLab vials and always make a starter. Usually the starter takes 2days before I start seeing Krausen.
Once I pitch this I usually have heavy airlock activity and a nice 1-2inch head of Krausen within 4-6 hours!!!
 
I give my fermenter a swirl 24 hours after pitching if i see no signs of fermentation. And every Saison I have done required a swirl to throw the yeast back into suspension about half way through the ferment.
 
I just had one that started slow with no visable signs after a day, could be because my temps... haha were pretty low.. almost 40 degrees.

I let it go and the yeast formed at the top and another day went by before they had foam on the top. The foam wasn't nothing spectacular or large but it's done now after a slow week and the yeast is starting to drop out.

no worries
 
You did nothing wrong by shaking it, although you didn't do much. CO2 is heavier than air, and so if fermentation had already started, the O2 was already pushed out by the CO2 being generated. If fermentation had NOT started, then shaking it would have put O2 back into solution (which is what the yeast needs anyway to reproduce in it's primary phase).

So either way you're fine. I think the biggest danger is if you shake it up the top could pop off the carboy and make a huge mess, not unlike a giant beer bottle.
 
I shook the carboy (gently side to side) after I poured in the hydrated yeast. I gently slopped it around until it was a uniform creamy color then left it alone. Good thing I had the blow-off tube. :)
 
Back
Top