Dry hop secondary container

I thought I'd come back to this question, which has received no further discussion in this thread. The reason that beer clears faster in a secondary is related to the fact that beer clears faster when cold crashed.

For a beer that has finished primary fermentation there will be a total number N of yeast cells in the beer. At a given temperature T with everything in thermodynamic equilibrium (I'll come back to this below), a certain fraction f_s of the cells will be in suspension and a certain fraction f_c will be found in the yeast cake at the bottom of the fermenter, with f_s + f_c = 1. The total number of yeast cells in suspension N_s is equal to N*f_s. The yeast-cake state is the lower-energy state, but the effects of entropy will always ensure that some yeast is in suspension. Now N_s can be reduced in two ways. The first way is to lower the temperature T, which decreases the equilibrium ratio f_s/f_c, and because N is constant in this case, N_s = N*f_s becomes smaller, resulting in clearer beer. The other way to reduce N_s is to reduce N, which can be done by racking to a secondary. In this case N_s = N*f_s becomes smaller because N has been reduced.

Now in reality, I suspect that the equilibrium state in most primaries is a fairly clear beer. But it usually takes quite a while for the beer to become reasonably clear, longer than many of us are willing to wait. By racking to a secondary, one can put the beer in a state that is further away from equilibrium (most of the yeast in suspension). Thus the approach to a clear beer becomes faster. Same thing for cooling. The beer is again put further away from equilibrium, speeding up the approach to a clearer beer.

I have certainly experienced the clearing effects of a secondary, and I suspect some of you all have also. IIRC, this was the major result of the secondary vs no-secondary experiment recently run by Basic Brewing Radio.

 

Are you sure this applies to the question at hand in any significant way? What would cause inactive yeast cells to overcome gravity and rise? Brownian motion?

 

Am I sure? Fairly sure; at least it makes sense to me. I am happy to be corrected, if there is a better explanation. The mechanics of suspension is certainly Brownian motion (at least to some degree). Now there may be some biochemistry (about which I know practically nothing) going on that is important, but in-so-far as this may be a an issue that is mostly described by physics, I believe that my explanation captures the essence of the dynamics.

 

I think you may be reading more into the Wyeast quote than what they are saying. Flocculation is reversible, but this 'defloc-ing' is caused by the presence of sugars. That doesn't really apply to the situation we were discussing.

At least that's my understanding. But I'm more than willing to be persuaded by evidence to the contrary. If you have seen anything that discusses reversibility without sugars, please share.

 

You are indeed correct, the topic of secondary or not was addressed on Basic Brewing Radio:

May 24, 2012 - Secondary Experiment Results

James and Chris Colby, editor of Brew Your Own magazine, take a look at the results of the BYO-BBR Collaborative Experiment testing the effect of racking to a secondary fermenter.

The ‘general conclusion’ was that in the end (the beer in the bottle/keg) there was not a significant difference between using a secondary or not.

As a result of the experiments, James Spencer ‘recommends’ the following:

· If you bottle your beers there is no need to conduct a secondary

· I you keg your beer with a ‘stubborn’ yeast then you should conduct a secondary

Cheers!

 

And you can't cold crash the beer in primary because...?

 

I know someone who has secondaried (a word?) in a plastic bucket while making a blueberry wit several times with no issues. He ferments the wit in a glass carboy for about 2 weeks, then racks to a plastic bucket with the blueberries for 2-3 weeks of secondary.

 

Is the volume of the blueberries reducing most of the headspace?

 

I don't know exactly how much it's displacing. It's 5 lbs of blueberries in a typical ale pail, so probably a fairly significant amount.

 

This works really well, and is what I've switched over to doing. If I have a yeast that doesn't want to flocculate I just fine it after a 48 hour cold crash. Just make sure you give the yeast enough time to clean up off flavors or fermentation byproducts before cold crashing.

 

Matt,

You make several interesting points.

If you are anxious to get your beer ‘completed’ quickly then there is indeed a benefit to racking to a secondary. As you state: “that beer will definitely clear quicker when racked.”

I personally am not in a rush to drink my beers so I am willing to wait for the beer to just clear on its own pace. I bottle my beers and I am personally not concerned about having ‘more’ sediment in my bottles. I simply pour the beer out and I leave the sediment behind. Whether the layer of sediment is 1/16th of an inch or 1/8th of an inch makes no difference to me. If the amount of sediment in a packaged beer is a concern to somebody then conducting a secondary will indeed lessen the amount of sediment.

For me the decision on whether to conduct a secondary is a classic ‘risk vs. reward’ decision. From my perspective the risks are potential infection and oxidation. There are no rewards for me in terms of conducting a secondary. So the ‘answer’ is simple for me: I don’t conduct a secondary for my ales.

Let’s discuss the potential risks of infection and oxidation. Firstly what we should all recognize is that every homebrewed beer is technically infected and oxidized. Every batch of homebrewed beers has microorganisms other than the beer yeast we pitched. Every batch of hombrewed beer has been exposed to oxygen so some level of oxidation has occurred. As homebrewers we typically only refer to a beer as being infected if the resulting beers have ‘sufficient’ off flavors caused by the infecting microorganism (e.g., bacteria, wild yeast, etc.) to make the beer taste ‘off’. We also only typically refer to the beer as being oxidized if there is ‘sufficient’ off flavors from the oxidation processes; e.g., a cardboard taste, a sherry-like taste, other off flavor tastes described by hopfenunmaltz in his post. There is no doubt in my mind that the racking to a secondary process introduces additional microorganisms and additional oxygen to the beer. Whether these additional microorganisms and oxygen will provide ‘sufficient’ off flavors is dependent on varying conditions. As you discussed, the aspect of time in the bottle/keg plays into this as well. It may take many months for the oxidation off flavors to get above a threshold level for example. It may also take several months for a low level infection to present itself. If you consume the particular batch of beer quickly then the homebrewer would never now there was a ‘problem’.

I personally tend to brew a lot of batches of different styles of beer so it is not unusual for me to have some beers for an extended period of time:

· I have a Belgian Ale that I brewed with ‘regular’ and Brett yeast that is over a year old (bottled on 4/6/11)

· I recently finished an English Ale batch that was bottled on 6/14/11

· I recently finished a Saison batch that was bottled on 8/10/11

· I had batches of CAP and Bohemian Pilsners that were one year old in the Feb. /March 2012 timeframe.

As regards the topic of cold crashing, I personally do not perform a cold crash since I do not have a means to do that. I personally am happy with what time and gravity does for my beers.

Cheers!

Jack

 

I would guess it is a trade off which is why people have always found contradicting results. By keeping the beer in the primary, your gravity curve is much farther along. If you rack to secondary, you reset your gravity curve by disturbing everything but the racking also causes more yeast, proteins, etc. to crash into each other and floc. These flocs weigh more and will fall out faster. It's the reason all water treatment plants have flocculation basins to disturb the water.

I prefer using a secondary because after checking the SG I assume I'm replacing a lot of the CO2 blanket with fresh air which contains O2. I like the reduced head space of a secondary.

 

To the OP question, I use either plastic or glass for secondary - whichever doesn't have a batch fermenting.