To secondary or not.

[SmokinBarleyPops]

My kolsch is nearing the end of its diacetyl rest and i am wondering if should transfer to a secondary before sending to it lagering temp.

I am attaching a pic of my carboy currently. It appears there is a large amount of krausen and yeast stuck to the top and neck.

What would you do. Ferment is complete fg of about 1.009. Plan on lowering the temp from 68 to 40 degrees over 4 days, then 2 weeks a 40.View attachment 1422917176627.jpg

Also am I ok to keep it set up as a blowoff to prevent suck back while cooling, or should I just put on some sanitized foil?

 

[WayFrae]

If I were about to lager I think I would rack to secondary to minimize head space since air will be getting sucked into the carboy upon cooling. I think you will still get suck-back with a blow-off tube, and possibly more than with a 3 piece airlock depending on the size of your container. I would use sanitized foil or an S shape airlock before using a blow-off tube.

 

[mblanks2]

Personally, I would leave it in the carboy you have it in for 21 days before starting my cold crash. Then replace the blow off with sanitized foil. Move it to the cold crash location and let it ride there before racking to keg or bottling.

 

[fastengine]

I secondary for 2 reasons.
1) To get my beer off the precious yeast cake so I can harvest for repitch.
2) I primary in a brew bucket and would much rather secondary in a plastic or glass carboy with an airlock.

I know lots of people here like to not disturb their beer and just keep it in a primary for fear of a possible infection or oxidation. Since you are using a carboy if you don't want to harvest the yeast or take a chance on infecting or introducing O2 to your beer I'd just put an airlock on what you have and start your lagering process.
I'd use a starsan soaked towel to clean out the mouth of the carboy to make sure the bung seals.

 

[madscientist451]

I agree w/fastengine above. I take a somewhat old school approach and like to get the beer away from the dead yeast. Many people say that's BS and don't worry about it. Do what you think is best.
Your carboy does look kind of nasty, I use buckets for primary then rack to a clean carboy.
Your Kolsch will be better after your lagering, but I'd pull a sample after 2 weeks and maybe give it another 4-6 weeks if you don't think its ready. I've made several Kolsch brews and liked them better with a longer period of cold aging.

 

[masonsjax]

Wow, every single reply thus far is unexpected to me. Well, I'm gonna be the oddball I suppose, but I would leave it i primary, put an S bubbler airlock on it (they can bubble backwards), drop the temp immediately for a few days if you really feel like it, and keg/bottle it. A diacetyl rest is really not necessary (especially for an ale yeast) unless you have a diacetyl problem, and there's no need for extended lagering prior to packaging. If you just want clear beer, that can happen afterwards just as well.

I've made kolsch dozens of times and I usually just ferment in primary for a week or so and keg. It clears up by the time it's carbonated and tastes just right.

 

[SmokinBarleyPops]

Thanks for the feedback, im not ready to do any yeast harvesting, but will definately heed some of the advice and clean the neck and put clean airlock assembly.

This beer was my first venture into all grain and a well started yeast and didnt use the blow off from the start, probably attributing to the caking on the top of the carboy, lesson learned.

The one thing mentioned was that the diacetyl rest may not be necessary.....but can it hurt?

 

[masonsjax]

No, the rest wont hurt anything. Neither will yeast dried up in the neck of the carboy. Beer is pretty forgiving.

 

[trentm]

Also am I ok to keep it set up as a blowoff to prevent suck back while cooling, or should I just put on some sanitized foil?

I've been on a mission to warn homebrewers about the effects of cold crashing and aeration. Those who have kegged beer know the fact that cold beer holds more CO2 than warm beer and it is the same for any gas including air. And those who have cold crashed know that, without some kind of remediation, air enters the fermenter. Many just pray to beer gods that the residual CO2 in the headspace protects the beer from the air. Recently, I did a very unscientific experiment that, to me, illustrates that air going into a fermenter during cold crash actually ends up in solution in the beer. I have posted these images before but as I said, I'm on a mission.

The first image is at 72F before starting the cold crash. The glove was attached to the carboy with several wraps of electrical tape and purged 5 times with CO2 through a hole clipped in the index finger then inflated and tied off. The glove in my hand served as a control and was tied at the wrist and inflated through the index finger and tied. The control glove remained inside the freezer throughout the experiment.

The second image is 24 hours after the temp was brought down to 34F. Notice the difference in the control compared the treatment.

The third image is 72 hours after cold crash. All the CO2 in the attached glove is gone and we (at least I) assume that most of the gas went into solution in the beer as there is not enough headspace to hold that much gas.

The fourth image was taken 48 hours after the freezer temp had been brought back to 72F and you can see that some of the gas has came back out of solution as evidenced by the re-inflation of the glove and bubbles at the surface of the beer. At first I thought the bubbles and re-inflation may have been due to a restart of fermentation but I have since bottled conditioned this beer with exactly the the carbonation expected from a completely finished beer.

This observation has convinced me that some form of remediation is necessary to protect the beer from aeration during cold crash. In addition, I think this method of purging and inflating a glove with CO2 will protect the beer from aeration during cold crash. There are other methods out there that would also work. The best but not feasible for many homebrewers would be the method that many commercial breweries follow when cold crashing. That is to do the cold crash under positive CO2 pressure. In effect that is what is happening with the inflated glove method in a less controlled manner. This would be easy to do if cold crashing in a corny keg or any vessel that can handle pressurized gas. A less effective but possibly satisfactory method would be to put a solid bung in the carboy. The problem I can envision here is if the bung were removed at cold temperature there would be a vacuum creating a suck back of possibly contaminated air. But this air would have little time to go into solution before kegging or bottling.

 

[bragona71]

Thanks for the feedback, im not ready to do any yeast harvesting, but will definately heed some of the advice and clean the neck and put clean airlock assembly.

This beer was my first venture into all grain and a well started yeast and didnt use the blow off from the start, probably attributing to the caking on the top of the carboy, lesson learned.

The one thing mentioned was that the diacetyl rest may not be necessary.....but can it hurt?

this post prompted me to do some research and found this VERY interesting article.You might enjoy also



http://www.professorbeer.com/articles/diacetyl.html


BTW..trentm Great experiment I find kegging and conditioning gets me the same results as in carboy as far as clear beer is concerned

 

[masonsjax]

cold beer holds more CO2 than warm beer and it is the same for any gas including air.

This is not entirely correct. Air is not a gas. It is a blend of various gasses. The fact that cold beer absorbs CO2 better than warm beer does not mean that other gasses will also be absorbed at an accelerated rate. Nitrogen for instance will not absorb into beer, cold or otherwise, even at fairly high pressures. That's what makes a nitro tap work and why pure nitrogen (or argon) is used to serve wine on tap. Oxygen is the gas we're worried about due to the undesirable flavor of oxidized beer. A miniscule amount of oxygen may absorb into beer under the scenario of your experiment, but I believe the absorption rate of oxygen into water at least, is pretty low. To absorb enough O2 to actually ruin 5 gallons of beer would require agitation, splashing, etc.

 

[MEPNew2Brew]

This is not entirely correct. Air is not a gas. It is a blend of various gasses. The fact that cold beer absorbs CO2 better than warm beer does not mean that other gasses will also be absorbed at an accelerated rate. Nitrogen for instance will not absorb into beer, cold or otherwise, even at fairly high pressures. That's what makes a nitro tap work and why pure nitrogen (or argon) is used to serve wine on tap. Oxygen is the gas we're worried about due to the undesirable flavor of oxidized beer. A miniscule amount of oxygen may absorb into beer under the scenario of your experiment, but I believe the absorption rate of oxygen into water at least, is pretty low. To absorb enough O2 to actually ruin 5 gallons of beer would require agitation, splashing, etc.

Always wondered how the served wine on tap with no carbonation!

 

[paperairplane]

I ferment in a bucket. I put cheap vodka in the airlock. I cold crash all the time and have never had a beer change the fluid level in the airlock. I don't notice any oxidation issues in my beers.

As for secondary, I never do it unless I am adding oak or something like that. I dry hop in primary.

Back to the OP - I keg, so any lagering I would do in the keg - which is kind of a secondary. I have cold crashed ales in primary fermentation bucket and not had time to package - effectively lagering in primary.

 

[trentm]

This is not entirely correct. Air is not a gas. It is a blend of various gasses. The fact that cold beer absorbs CO2 better than warm beer does not mean that other gasses will also be absorbed at an accelerated rate. Nitrogen for instance will not absorb into beer, cold or otherwise, even at fairly high pressures. That's what makes a nitro tap work and why pure nitrogen (or argon) is used to serve wine on tap. Oxygen is the gas we're worried about due to the undesirable flavor of oxidized beer. A miniscule amount of oxygen may absorb into beer under the scenario of your experiment, but I believe the absorption rate of oxygen into water at least, is pretty low. To absorb enough O2 to actually ruin 5 gallons of beer would require agitation, splashing, etc.

http://www.engineeringtoolbox.com/gases-solubility-water-d_1148.html

 

[Black Island Brewer]

http://www.engineeringtoolbox.com/gases-solubility-water-d_1148.html

That's a cool site! I'm now much less worried about O2 in the headspace. 0.07 grams at zero C for pure oxygen vs. 3.5 grams at zero C for CO2 is a HUGE difference! And since we're using talking about atmospheric O2, it is even less!

I wonder if it being water vs. beer makes much of a difference...

 

[dyqik]

That's a cool site! I'm now much less worried about O2 in the headspace. 0.07 grams at zero C for pure oxygen vs. 3.5 grams at zero C for CO2 is a HUGE difference! And since we're using talking about atmospheric O2, it is even less!

I wonder if it being water vs. beer makes much of a difference...

The difference it makes is that oxygen dissolved in the beer will slowly oxidize something and be removed from the beer. And then it will be replaced by the oxygen from the headspace dissolving into the beer so that it comes back into equilibrium. Over time, the beer will slowly take up oxygen from the headspace until everything that can oxidize is oxidized, producing the oxidation off-tastes. CO2 on the other hand, will form carbonic acid, but it won't react further with the beer in a way that damages the beer. The absolute amount of oxygen dissolved in the beer relative to CO2 doesn't magically stop the oxidation rate.

Oxidation reactions are, however, much slower at low temperatures, so that can protect you for some time, as can the slow diffusion rate of the O2 from the headspace into the liquid. But it can't protect you indefinitely, so you should still aim to minimize O2 in the headspace of secondaries, kegs and bottles if you expect the beer to remain there for some time. How long is safe depends. For cask beer at 55 F and with air being pulled into the serving vessel, 4-5 days or so is enough to show enough oxidation to ruin a beer. Oxidation levels are noticeable (but desirable) in a day or two.

BTW, CO2 and O2 will not form layers above the beer such that no O2 can get to the surface, but the partial pressure of O2 will drop a bit closer to the surface, which slows the rate of O2 absorption into the liquid. During fermentation, the CO2 produced raises the pressure in the vessel, and drives a mixture of O2 and CO2 out of the airlock. Combined with the yeast using what O2 is in solution, the large volume of CO2 produced results in minimal O2 remaining in the primary after fermentation. However, once fermentation stops, O2 allowed back into the vessel can get into the beer and cause oxidation.

 

[Black Island Brewer]

The difference it makes is that oxygen dissolved in the beer will slowly oxidize something and be removed from the beer. And then it will be replaced by the oxygen from the headspace dissolving into the beer so that it comes back into equilibrium. Over time, the beer will slowly take up oxygen from the headspace until everything that can oxidize is oxidized, producing the oxidation off-tastes. CO2 on the other hand, will form carbonic acid, but it won't react further with the beer in a way that damages the beer. The absolute amount of oxygen dissolved in the beer relative to CO2 doesn't magically stop the oxidation rate.

Oxidation reactions are, however, much slower at low temperatures, so that can protect you for some time, as can the slow diffusion rate of the O2 from the headspace into the liquid. But it can't protect you indefinitely, so you should still aim to minimize O2 in the headspace of secondaries, kegs and bottles if you expect the beer to remain there for some time. How long is safe depends. For cask beer at 55 F and with air being pulled into the serving vessel, 4-5 days or so is enough to show enough oxidation to ruin a beer. Oxidation levels are noticeable (but desirable) in a day or two.

BTW, CO2 and O2 will not form layers above the beer such that no O2 can get to the surface, but the partial pressure of O2 will drop a bit closer to the surface, which slows the rate of O2 absorption into the liquid. During fermentation, the CO2 produced raises the pressure in the vessel, and drives a mixture of O2 and CO2 out of the airlock. Combined with the yeast using what O2 is in solution, the large volume of CO2 produced results in minimal O2 remaining in the primary after fermentation. However, once fermentation stops, O2 allowed back into the vessel can get into the beer and cause oxidation.

Good info indeed!

The cold storage temps make a huge difference. IIRC, the figures Charlie Bamforth quote are 50% shorter life for ever 10 C - eg: if a beer shows staling after 12 months at 0C, it will stale in 6 months at 20C, 3 months at 30C and so on.

I have always been anal about the O2 in headspace, doing closed transfers, purging with CO2, purging the bottling bucket, etc. I don't purge bottles, and the suckback during crashing has always concerned me. So my point is that while O2 is soluble, it's not as bad as I have been led to believe. The next datapoint needed is at what O2 level staling will be noticeable. I know that darker beers can be more resistant to staling, so i'm guessing it will be a moving target.