First time keg fermenting - check my process

[nonamekevin]

Hello,

I will be doing a Dunkel extract recipe from morebeer that I picked up over the holidays and I'm looking to ferment in a corny keg.

1. The recipe for the Dunkel recomends fermenting between 62-64F, while the temp for the yeast is recommended between 65-72F. I was planning on pitching at 62F. Thoughts?

2. I've been reading Palmers book and have been glued to the fermentation chapter. Palmer recommends starting fermentation temps on the lower end, then raise temps towards the end of fermentation to clean up diacetyl. After that, it goes into a long period of cold conditioning. Am I understanding correctly? (I simplified the chapter greatly).

I was planning on running an airlock off of the gas post on the corny, but I've been interested in pressure fermenting also. Palmer doesn't mention anything about pressure fermenting in his book, which I'm using as my main source of learning this hobby.

Ive got kegs to ferment in, I've got a kegerator to control temps, and I've got time. I'm looking for guidance on taking the fermentation out of the ale pale and elevating the final product. Any tips or advice is appreciated.

 

[JJinMD]

You will get better feedback if you provide more details. Post what yeast you are using and you might get very specific advice to that strain instead of general lager answers, particularly if you are trying to ferment under pressure with it.

As far as fermenting in a keg, keep in mind that you are going to have trub at the bottom of the keg, so you should either use a floating diptube or cut your diptube short to avoid sucking that up when you serve from it or transfer to a serving keg. Also, you are going to probably need to limit the size of your batch, if it were an ale, I would say 4 gallons max, but I have not fermented a lager in a keg, but I think you can get away with less headspace there. If you plan on pressure fermenting, you should get a spunding valve for your gas post to accurately and safely pressurize.

 

[nonamekevin]

Thanks JJinMD,

My yeast is liquid wyeast 3068, weihenstephan weizen. It was one of the recommended yeasts for the Dunkel recipe, and not knowing anything, it's the yeast I chose.

I was looking at a flotit floating dip tube setup to limit trub and either cutting the gas tube as short as possible to maximize headspace, or opting for a 6gal keg so that I can still brew a full 5gal recipe. Looking for tips.

*Just looked it up, and is a Dunkel a lager or an ale? This is my third batch I'm attempting, and I guess I misunderstood thinking that this was an ale....am I attempting a more difficult recipe?

 

[Deric]

Watching with interest as I'm getting ready to try the same thing.

 

[JJinMD]

What is the name of the Dunkel recipe? Is it a dunkelweizen?

 

[nonamekevin]

What is the name of the Dunkel recipe? Is it a dunkelweizen?

Yes, it is a dunkelweizen...https://www.morebeer.com/products/dunkelweizen-extract-beer-brewing-kit-5-gallons.html?variant=KIT237D

 

[Jim R]

That is an Ale and an Ale yeast.

If you are going this far with a pressure capable fermenter you might as well get a spunding valve and ferment it under pressure. You can read the pressure charts although I would probably just dial it in at 12 psi or so for fermentation. I would ferment it for 10-14 days, then cool it to serving temperatures at the correct serving CO2 pressure and pop the keg at day 21 or so. The floating dip tube would be very helpful for serving.

 

[bjhbrew]

I used that yeast in a Hefeweizen and it had a pretty substantial krausen. I think even 4g in a 5g keg might be pushing it. Also, wouldn’t pressure fermentation reduce the yeast expression likely desired from this yeast strain?

 

[nonamekevin]

I used that yeast in a Hefeweizen and it had a pretty substantial krausen. I think even 4g in a 5g keg might be pushing it. Also, wouldn’t pressure fermentation reduce the yeast expression likely desired from this yeast strain?

Ive read that somewhere also, which is why I'm kind of leaning towards not pressure fermenting and doing a slow cold conditioning process, as per Palmers book.

Any additional thoughts?

 

[bjhbrew]

Do you have another larger fermenter? I think I’d do this one without pressure and with either a large headspace or adequate blowoff tube. If anything, you could transfer to you keg just as fermentation is winding down to get some natural carbonation.

 

[rkhanso]

I'll hopefully be pressure-fermenting in corny kegs the next time I brew. Keep in mind, I've not done this yet. But I've watched a lot of videos on the subject.
Most say that the pressure keeps krausen down considerably, but still need enough headspace to not clog up the fittings.
Floating dip setup or cutting the traditional tube shorter is common. People have good/bad about each method.
Most say that you can even ferment lagers at room temps when pressure fermenting - that the temp control is not as critical.

 

[nonamekevin]

Do you have another larger fermenter? I think I’d do this one without pressure and with either a large headspace or adequate blowoff tube. If anything, you could transfer to you keg just as fermentation is winding down to get some natural carbonation.

I was going to pick up the 6gal torpedo for fermentation and run a blowoff tube to some starsan. Still roughly 1gal of headspace. Maybe a 10gal torpedo would be better...

I'll hopefully be pressure-fermenting in corny kegs the next time I brew. Keep in mind, I've not done this yet. But I've watched a lot of videos on the subject.
Most say that the pressure keeps krausen down considerably, but still need enough headspace to not clog up the fittings.
Floating dip setup or cutting the traditional tube shorter is common. People have good/bad about each method.
Most say that you can even ferment lagers at room temps when pressure fermenting - that the temp control is not as critical.

Ive heard some people don't start the pressure fermenting until after 1-2 days after pitching, but again, I haven't heard too much explanation behind the practice. Also bjhbrew mentioned that pressure fermenting might not be the right approach for this recipe/yeast, due to possibly limiting the expression from this strain of yeast.

I appreciate everyone's input and enjoy the discussion.

 

[Jim R]

There is no problem pressure fermenting that recipe or that yeast especially at very modest pressures like 12 psi. In fact, there is no style of beer that I wouldn't ferment now under modest pressures like this. I haven't found any downside at all except maybe a little extra cost.

If you can afford a little extra cost, it is worth getting a really high quality spunding valve like the Spundit 2.0. This guy has a lot of good videos on pressure fermenting and fermenting in kegs.

 

[bjhbrew]

I can vouch for using a 10g torpedo keg for fermenting, it’s what I’ve been using and it’s worked great. My usual batch size is more like 7g so maybe the 6g would work for you if doing 5g batches. You’re correct that pressure is effective at keeping the krausen pretty low. Definitely no harm in trying a pressure ferment for this recipe, or like you say let the pressure build after a couple days. Since getting my fermenting keg my routine has been to hook the gas port of the fermenting keg to the out post of my serving keg to purge it using co2. I ferment under no pressure for about 3 days, when I see activity winding down I throw the spunding valve on the serving keg gas post to build some pressure in both vessels. I’m not fussed about getting it to full carbonation or anything, it just gets me some pressure and a bit of carbonation so I can cold crash then I put the co2 bottle on and let it condition and carbonate cold. When I transfer to my serving keg the beer is already perfectly carbed and well on its way to tasting its best.

 

[nonamekevin]

Thanks all,

For pressure fermenting, how does temp control play into the equation? It seems people are saying you can ferment at higher temps with pressure fermenting, but I haven't seen a direct relationship. If I'm fermenting at 10-12psi, what does that mean for temp above recipe recommended? This recipe says 62-64F fermentation temp.

On cold crashing, Palmers book suggests a cold conditioning period after diacytl rest, with the conditioning phase slowly lowering the temp of the fermentation. Unless I misunderstood, a severe temp change could cause the yeast to go into survival mode and produce something unwanted, I have to go back and read that section. Any thoughts on this?

 

[rkhanso]

On this BeerSmith video, Chris White and John Blichmann talk about doing a test ferment in the +80F range. I haven't heard if they've done it yet though.
They did a test brew and the results are pretty interesting...though the ferment temps weren't outrageously high or low.

 

[Jim R]

The advantages of pressure fermentation for me are -
1. can ferment at higher temperatures which is probably most useful for lagers or in the warmer summer months.
2. Faster fermentation especially when fermenting at higher temperatures
3. Less risk of oxidation as it is a completely sealed fermentation
4. Some free carbonation (free CO2) although I don't usually shoot for perfect carbonation levels during fermentation

There is no need though to ferment at higher temperature if you are in no hurry. With that recipe, I might ferment at 65-66 degrees and 12 psi.

I usually then remove the spunding valve and cold crash by dropping the temperature slowly over a couple days and adding CO2 to my desired carbonation level.

 

[Knightshade]

I was going to pick up the 6gal torpedo for fermentation and run a blowoff tube to some starsan. Still roughly 1gal of headspace. Maybe a 10gal torpedo would be better...

Ive heard some people don't start the pressure fermenting until after 1-2 days after pitching, but again, I haven't heard too much explanation behind the practice. Also bjhbrew mentioned that pressure fermenting might not be the right approach for this recipe/yeast, due to possibly limiting the expression from this strain of yeast.

I appreciate everyone's input and enjoy the discussion.

I've done 2 batches now in a Torpedo 6G keg and outside of needing to tilt the damn thing to get the damn transfer to start flowing again every once in awhile (w/floating dip tube), I haven't had any issues. (To be fair, I had to do this w/my fermonsters too.)

I've started using Fermcap for the first time ever due to a concern with clogging the poppet, and that has been working pretty well I guess. Haven't noticed anything getting out into the blowoff tube. Latest batch ended up at 10.1% w/2 sachets of S-05 too. I don't know what my actual output was for this batch as I didn't weigh the keg before throwing it in the kegerator but it seemed pretty damn full.

 

[Climb]

@ nonamekevin - you mention fermenting in a keg, doing a diacetyl rest and then cold crashing. Do you have a plan to deal with the pressure change due to the temperature change during the cold crash? There are several options, some are mentioned above. We can cover them if needed.
Fermentation should be complete after the diacetyl rest, so don't worry about the yeast flocculating during the cold crash. The purpose of the cold crash is to help clear the beer, right!
I also have not seen detailed information or empirical data on how fermentation temperature and fermentation pressure affects beer characteristics. I have read about what is expected and general rules of thumb, but I am not sure if this is dogma, conjecture or developed through the scientific method. Of course this will be highly yeast dependent and probably needs to be developed through experimentation. May be others can share some pointers on this topic for us.
You also ask about the reason for not spunding (fermenting under pressure) at the beginning of fermentation. The reasons that I can think of are: 1. yeasts create most of the flavor compounds in the first several days of fermentation and fermenting under pressure can change how the flavor compounds develop. 2. brewers don't want to get to get yeast blow off in the spunding valve or worse that might occur during a vigorous fermentation. This last point makes cleanup and sanitation of the spunding valve easier.
Good luck with your brew.

 

[nonamekevin]

@ nonamekevin - you mention fermenting in a keg, doing a diacetyl rest and then cold crashing. Do you have a plan to deal with the pressure change due to the temperature change during the cold crash? There are several options, some are mentioned above. We can cover them if needed.
Fermentation should be complete after the diacetyl rest, so don't worry about the yeast flocculating during the cold crash. The purpose of the cold crash is to help clear the beer, right!
I also have not seen detailed information or empirical data on how fermentation temperature and fermentation pressure affects beer characteristics. I have read about what is expected and general rules of thumb, but I am not sure if this is dogma, conjecture or developed through the scientific method. Of course this will be highly yeast dependent and probably needs to be developed through experimentation. May be others can share some pointers on this topic for us.
You also ask about the reason for not spunding (fermenting under pressure) at the beginning of fermentation. The reasons that I can think of are: 1. yeasts create most of the flavor compounds in the first several days of fermentation and fermenting under pressure can change how the flavor compounds develop. 2. brewers don't want to get to get yeast blow off in the spunding valve or worse that might occur during a vigorous fermentation. This last point makes cleanup and sanitation of the spunding valve easier.
Good luck with your brew.

I'm still not set on cold crashing, as I understand it. So far, my proposed process is purely based on Palmers book and the recipe suggestions, as follows:
1. Pitch yeast at lower end of recipe fermentation temp (62F)
2. Ferment for a few days until 2-5 points away from FG, then raise temp 5-10F for diaceytl rest (67-72F). Continue until FG met (4 days min expected).
3. Chill wort by 2F per day to 47-53F (~7 to 13 days)
4. Transfer to serving keg, carb up over a couple of weeks.

For the above process, it could be about 3 weeks until transferring. Palmer explains the slow cold conditioning process as a way to avoid thermal shock which could cause yeast to excrete fatty acids and lipids, signaling other yeast cells to shut down, premature floculation, etc.

Im still interested in pressure fermenting, but how can it be incorporated into the above process? What should I consider for a temperature control plan?

 

[Climb]

@nonamekevin - Step 3 above is what I am talking about. Your plan is to decrease the temperature of the fermentor (keg) from 67-72F to 47-53F. That's somewhere between a 25F to 14F temperature change. If the fermentor is sealed, the beer and C02 in the head space will contract, causing a decrease in pressure in the fermentor. If you have a blow off hose connected during this time, you may have whatever the free end of the blow off hose is submerged in, get sucked back into the fermentor. This is often refered to as "suck back". If the fermentor is open, you will get atmospheric air, i.e. oxygen sucked into the fermentor. This is why several people above suggested to connect your CO2 tank to the gas in post of the fermentor during this phase of fermentation.
I don't have any solid advise for you on a fermentation pressure and temperature profile for your recipe and desire to pressure ferment. From what I know on this, which is limited, I would ferment until high krausen, may be 3 days, with a blow off hose. Then switch to using the spunding valve set somewhere between 5 and 30 psi. Be on the high side if you intend to naturally carbonate the beer in the fermentor or on the low side if you are concerned about yeast off flavors. I would stay with the fermentation temperature profile you mention above as you are not in a rush. However if you want to experiment with increased fermentation temperatures, I would let the temperature free rise to around the mid to high 70sF after the spunding valve is installed. Ultimately the fermentation temperature and pressure profile is something that you will have to decide on. I don't think you will find a detailed procedure for this recipe and yeast.

 

[odie]

I'm doing keg fermenting in 5 gal cornies. And serving from the same kegs. Where I'm at so far...

I ferment full volume, 5 gal of wort. A corny holds 5.5 gal. I've found no reason to reduce batch size. 5 gal of wort under pressure will not have a "blow out" (except hefe)

I screen all the kettle wort thru a 200 micron bucket strainer first so no trub issues. I get very clean yeast cakes to harvest.

I've done full length dip tube. You can harvest the yeast with a short picnic tap into a mason jar. After that, the first pint or two you get clear beer to drink.

I've done floating dip tube. No yeast harvest but you can re-pitch fresh wort into the "dirty" keg and make another batch. You get clear beer to drink on the first pint.

I replaced all my PRVs with lower pressure ones (red), 25-30 PSI, which is enough to fully carbonate at room temps without over carbing. The original grey PRVs are about 100 PSI. You can also get 10 PSI (blue) and 15 PSI (purple) ones too. If you don't have a real spunding valve then a blue PRV works just fine.

Pressure suppresses yeast "expression". Good for lagers. Not so good for ales. Bad for hefewiesen.

Lagers respond well to pressure as you don't want yeast "character" that would normally result from higher temps. Probably anything from 5-15 psi is probably fine. That's typical spundiung valve range. I've also skipped the spunding valve and just used a 25-30 psi PRV and let it ride. You can ferment at normal larger temps/time or let it run warmer/faster.

Ales, I use a blow off tube on the gas post with the poppet removed. With a full 5 gal of wort in a corny I rarely get any blow off. This lets the yeast "express" itself properly. Once the CO2 bubbling slows after a couple/few days (this indicates peak krausen has passed), install the gas post/poppet and set your spunding valve to whatever you think (5-15psi) and let it finish & carb up.

Hefes...DO NOT LIKE PRESSURE...under pressure it will still blow krausen out the PRV...and it will taste bland...NO BANANA OR CLOVE...

Hefes...Use a blow off tube...in a large bucket...once the krausen is done blowing out, install gas post and spund at low PSI. Maybe 5psi?


well...this is what I'm observing so far...