ferment, naturally carbonate, serve in one keg

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twd000

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Posting this thread under Kegging forum, although it's really a combined fermenting/kegging topic.

Looking for feedback on my plans - shoot holes in it, suggest improvements, or let me know if anyone has tried it.

Currently I ferment 5 gallon batches in 6.5-gallon glass carboys, then siphon to corny kegs and force carbonate.

I've been reading about closed transfers, cold-side aeration, LODO brewing and formulating ideas on how to improve/streamline my process without going full LODO.

1. traditional HIDO BIAB brew day, rack to corny keg with auto-siphon. Attach Clear Beer Draft System (or generic knockoff) to liquid post.

2. cool to pitching temp in fermentation chamber, pitch yeast

3. attach rudimentary blow-off tube to gas-out post and terminate it in a jug of Starsan for first ~3 days of fermentation.

4. swap blowoff tube for spunding valve and set to 30 psi to achieve 2.5 volumes carbonation.

5. move to kegerator to crash cool and serve

Wah-lah! Closed fermentation and serving, no oxygen ingress, only one vessel to clean instead of two. No permanent modification to my kegs in case the idea doesn't work



Questions:
Can I fit a 4.5 gallon batch into a corny without clogging the gas-out blowoff? Would a few drops of Fermcap-S allow me to ferment full 5 gallon batches? What about fermenting under ~2 psi of back pressure?
How do I anticipate when I'm at 4 gravity points remaining? Can I temporarily set the spunding valve at ~2 psi and attached a picnic tap to pull a liquid sample? I've read of people estimating specific gravity by weight with a precision scale, but not sure how feasible that is.
How long do I have at 40F before yeast autolysis kicks in? I've read about it, but never tasted or experienced it. I've had 4-month old bottle-conditioned Sierra Nevada that was stored warm and shows no signs of autolysis. Isn't that yeast sitting on the bottom basically the same as my keg, just more of it?
 

Gnomebrewer

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Questions:
1. Can I fit a 4.5 gallon batch into a corny without clogging the gas-out blowoff?
2. Would a few drops of Fermcap-S allow me to ferment full 5 gallon batches?
3. What about fermenting under ~2 psi of back pressure?
4. How do I anticipate when I'm at 4 gravity points remaining? Can I temporarily set the spunding valve at ~2 psi and attached a picnic tap to pull a liquid sample?
5. I've read of people estimating specific gravity by weight with a precision scale, but not sure how feasible that is.
6. How long do I have at 40F before yeast autolysis kicks in? I've read about it, but never tasted or experienced it. I've had 4-month old bottle-conditioned Sierra Nevada that was stored warm and shows no signs of autolysis. Isn't that yeast sitting on the bottom basically the same as my keg, just more of it?
1. It depends on the yeast. Lager yeast = yes; Hefe yeast = no.
2. Fermcap will help, but you're still not likely to get 5 gallons into a keg without major blowoff.
3. 2psi is bugger all. At 15psi yeast will still be happy and the krausen is reduced, but I still doubt you'll cope with 5gal in a keg. With fermcap, 15psi and lager yeast, you might just be OK.
4. Get to know the yeast you're using. You can definitely run the entire ferment under pressure so that you can take samples through a tap.
5. Not sure. Just use a hydrometer.
6. IME, longer than the beer will be left for. I've only ever had it in old starters/stored yeast, not batches of beer.
 
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twd000

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funny I just finished a hefe batch in my carboy. Definitely a lot of krausen. How small would I have to go to avoid blowoff? 4-gallon batch?
Maybe I could do an 8-gallon brew day and ferment two 4-gallon batches
 

Gnomebrewer

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It depends on the hefe yeast. WY3068 wouldn't want any more than 4gal in the keg, preferably 3.5. You don't want to ferment these under pressure either - it subdues the yeast flavours (apparently). I'm not sure about American Hefe yeasts (never used them).
 

McKnuckle

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Your process is very close to what I've done for the last few batches, since acquiring CBDS and William's Brewing floating dip tubes.

I would just advise not to get hung up on maxing out your keg. Just leave a minimum half gallon of headspace (yeast dependent as noted above), remove the concern of drawing solids into your blow-off tube, and be happy with a simple process and a little less beer.

Also, I do not have a spunding valve. I purchased a simple 10 psi check valve, attached to the end of the blow-off tube, which I remove when the bubbles slow down. The beer mostly carbonates itself, but not fully. I'm fine with this for now, but a proper spunding valve would be ideal. Personally I would not set the pressure relief higher than 15 psi.

With this method and some patience, there is no need to take samples and time things to match a particular degree of remaining points. Typically around the 2 week mark, I will take a single FG gravity sample by hooking up a picnic tap. Then it's off to the keezer to condition and serve.

So far I have had zero issues with flavors, even in a pale lager over a couple of months.

One thing that changes with a top draw system is that you never dispense and remove any sediment, so once the float gets near the bottom, it will all be there. This happens higher up than you might expect, at least so far in my experience. But the process has overwhelmingly positive aspects so this is a small compromise.
 
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McKnuckle

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One more tidbit of advice:

1) Remove the floating dip tube before draining wort to your keg
2) Chill to pitching temp if it's not there already
3) Aerate the wort with your preferred method
4) Attach floating dip tube, pitch yeast, rock and roll

The reasons for this sequence are first, to aerate only once you're about to pitch yeast; and second, if you aerate with a violent technique such as shaking or with a drill attachment, you don't want the silicone tube in there. It will possibly get tangled or worse.
 

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I've always wanted to do this, only even more so than you're suggesting. In a thread about brewing on a boat, I suggested tossing some DME and hops in a keg and then boiling water a few liters at a time to dump in the keg. Tie it up and dangle in the water for a couple hours to chill and aerate, then pitch yeast and use a spunding valve to carbonate, then a small co2 tank or cartridges to serve. It probably wouldn't make competition level beer, but it would be a uniquely low-effort way to brew.
 
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twd000

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Your process is very close to what I've done for the last few batches, since acquiring CBDS and William's Brewing floating dip tubes.

I would just advise not to get hung up on maxing out your keg. Just leave a minimum half gallon of headspace (yeast dependent as noted above), remove the concern of drawing solids into your blow-off tube, and be happy with a simple process and a little less beer.

Also, I do not have a spunding valve. I purchased a simple 10 psi check valve, attached to the end of the blow-off tube, which I remove when the bubbles slow down. The beer mostly carbonates itself, but not fully. I'm fine with this for now, but a proper spunding valve would be ideal. Personally I would not set the pressure relief higher than 15 psi.

With this method and some patience, there is no need to take samples and time things to match a particular degree of remaining points. Typically around the 2 week mark, I will take a single FG gravity sample by hooking up a picnic tap. Then it's off to the keezer to condition and serve.

So far I have had zero issues with flavors, even in a pale lager over a couple of months.

One thing that changes with a top draw system is that you never dispense and remove any sediment, so once the float gets near the bottom, it will all be there. This happens higher up than you might expect, at least so far in my experience. But the process has overwhelmingly positive aspects so this is a small compromise.
glad to hear it's working for you. So do you just make 3-4 gallon batches now? Or make a 6-8 gallon batch and split into two kegs?

Assuming you're fermenting an ale at 65F, 10 psi pressure would only give you 1.4 volumes of CO2 - are you just using bottled CO2 to carbonate the rest of the way up to 2.5 volumes?

How long have you let beer sit on the yeast cake before you finishing drinking that keg?

I'm not worried about tangling the silicone hose. On low-gravity batches I don't bother aerating. On high-gravity batches I use pure O2 with a diffusion stone that I drop to the bottom of the fermenter.

Is the CBDS worth 2x the price of the Williams version?

Have you figured out a way to dry hop in the keg?
 
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twd000

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I've always wanted to do this, only even more so than you're suggesting. In a thread about brewing on a boat, I suggested tossing some DME and hops in a keg and then boiling water a few liters at a time to dump in the keg. Tie it up and dangle in the water for a couple hours to chill and aerate, then pitch yeast and use a spunding valve to carbonate, then a small co2 tank or cartridges to serve. It probably wouldn't make competition level beer, but it would be a uniquely low-effort way to brew.

I like the simplicity. The Aussies will tell you that even the chilling step is superfluous. Just let the wort cool overnight and pitch yeast the next day
 

McKnuckle

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I have 2.5, 3, and 5 gallon kegs. So I'll do up to 2, 2.5, or 4.5 gallons. Actually I've put 2.5 gallons in a 5 gallon keg also - that's my sweet spot for batch size.

I force carbonate in a keezer with CO2, set and forget method, 12 psi at 40F. Beer needs a couple of weeks to condition and taste good, so in that time it fully carbonates, hence the amount of natural carbonation is just a bonus. I don't rely on it.

The most time I've had a beer sit on the yeast so far is about 2 months.

The CBDS is a nicer engineered product for sure, and the available hop screen is something that William's does not offer. You can dry hop with loose pellets if you have the screen installed. Otherwise, I have a couple of hop canisters that fit into a keg opening - you can get them on Amazon.

I think it's worth trying one of each to compare for yourself. I think there is minimal difference in a 5 gallon keg, other than the aforementioned hop screen option. However, in a smaller keg, which matters to me, the CBDS tubing does not have to be cut down whereas the William's tubing does. It has to do with the weight of the float and the pliability of the tubing on each product. CBDS is more robust overall.
 
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twd000

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when you use the hop canisters - are what phase are you tossing it into the keg? Do you relieve pressure to take off the lid during active fermentation? I read that one of the advantages of spunding and closed fermentation was to preserve dry hop aromas, so wouldn't you lose a lot of that by letting a bunch of CO2 carry off volatile hop compounds?
 

McKnuckle

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Actually, I’ve used a canister only once, and in that case I loaded it into the keg at the beginning of primary. I’m a little obsessed about never opening the keg after the yeast is pitched. Probably could get away with it during active fermentation, so I’ll try that eventually.

I brew mostly German lagers and English styles, so I don’t have many American IPA batches under my belt.
 

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I like the simplicity. The Aussies will tell you that even the chilling step is superfluous. Just let the wort cool overnight and pitch yeast the next day
Truth. Since the original idea was for a guy on a boat, dangling the keg in the briny would be an easy step to add. If I did it at home, it would be no-chill.
 

McKnuckle

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As an aside, I find it interesting that threads on this topic seem to generate very little discussion. I think the floating diptube concept has not quite caught on, despite it being inexpensive, easy to use, and a great tool for keeping beer fresh by minimizing transfers.
 
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twd000

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As an aside, I find it interesting that threads on this topic seem to generate very little discussion. I think the floating diptube concept has not quite caught on, despite it being inexpensive, easy to use, and a great tool for keeping beer fresh by minimizing transfers.

I noticed that too. I think part of the problem is we're talking about an "off-label use". These floating dip tubes are sold as a way to drink clear beer faster. Most homebrewers (non-production schedule) are willing to wait an extra week for their beer to drop clear, or add a tsp of gelatin if they're in a hurry. So they don't see an advantage to spending ANY money on something if the tradeoff is just waiting a week

I don't see the manufacturers advertising these things as a way to:
1. ferment & serve in a single vessel (less cleaning)
2. support pressurized fermentation and closed transfers to minimize O2 ingress
3. rack off trub/yeast without opening the lid
 
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twd000

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another off-label use I thought of the other day:

what about rigging up a floating dip tube to rack clear wort from the boil kettle? I know my auto-siphon often clogs on hoppy beers when I get towards the bottom of the kettle. What if you rigged a silicone tube and float with a screen to the end of the racking cane? Toss it in the chilled wort and transfer clear wort to the fermenter until you reach the hop sludge at the bottom of the boil kettle.
 

Gusso

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Super interested in trying this. I think I will use a torpedo 15 gallon keg for a 10 gallon batch.
I sometimes put hot wort in my 10g Torpedo, pop on the lid and chill it in my pool. Pressurized fermentation and transfer to corny (5 gallon batches).
 
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