Unitank pour under pressure

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emerinohdz

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Hi!

This would be my first time using a Unitank (7gal SSBT) and using co2 in general (used to bottle and natural carbonate). I have a few questions that I haven't been able to find a concrete answer for and I'm hoping someone here can help me find an answer:
  1. With positive pressure (e.g. 10psi) on the tank, would it be safe to remove the co2 tank and pour beer through the sampling port or do I need to keep the co2 tank attached at 10psi to avoid pressure from dropping and potentially end up with negative pressure?
  2. If I do need to keep the co2 tank attached, wouldn't I run the risk of overcarbonating the beer? My understanding is that the headpressure will be gradually absorbed by the beer and more co2 will continue to flow.
  3. I would assume the answer for the first question would apply for dumping yeast through the dumping port, is this correct?
  4. If the tank's pressure is reflecting 10psi of head pressure and I connect the co2 tank, do I need to make sure to have the regulator set to at least 10psi? What's the risk (if any) of setting the co2 tank regulator to, say, 5psi instead?
Thanks for the help!
 
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emerinohdz

emerinohdz

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This post is probably not related to fermentation and yeast, I can't seem yo edit it though. If a moderator is able to move it to the appropriate section that'll be great!
 

Elric

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Hi!

This would be my first time using a Unitank (7gal SSBT) and using co2 in general (used to bottle and natural carbonate). I have a few questions that I haven't been able to find a concrete answer for and I'm hoping someone here can help me find an answer:
  1. With positive pressure (e.g. 10psi) on the tank, would it be safe to remove the co2 tank and pour beer through the sampling port or do I need to keep the co2 tank attached at 10psi to avoid pressure from dropping and potentially end up with negative pressure?
  2. If I do need to keep the co2 tank attached, wouldn't I run the risk of overcarbonating the beer? My understanding is that the headpressure will be gradually absorbed by the beer and more co2 will continue to flow.
  3. I would assume the answer for the first question would apply for dumping yeast through the dumping port, is this correct?
  4. If the tank's pressure is reflecting 10psi of head pressure and I connect the co2 tank, do I need to make sure to have the regulator set to at least 10psi? What's the risk (if any) of setting the co2 tank regulator to, say, 5psi instead?
Thanks for the help!
1) unless you plan to pour a HUGE sample, there is sufficient pressure to not worry about negative pressure.
2) not at 10 psi. 10 psi is around serving pressure for most beers at fridge temps. If your unitank is at room temp 10psi is only a light carbonation.
3) I don't think I have ever seen anyone do a yeast dump under pressure, I can see that having the potential to cause a real mess. if it were me I would have dumped yeast prior to pressurizing or would bleed pressure, dump, then repressurize. On this I have no experience so if someone else with experience comes along with a different answer ignore mine.
4) It's good practice to make sure your regulator is set either to the same or higher pressure than the tank you are connecting to. Without a check valve there is always risk of beer going up the gas line and potentially wrecking the regulator. At 10 psi and assuming your unitank is not filled to brim it probably would be fine, but it is best to get into the practice and staying there.
 
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emerinohdz

emerinohdz

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Thanks, Elric, your answer helps clarify a few of the concerns I've had.

Would be interesting to see if someone has a different view on 3), but I will for now release pressure, dump yeast amd then repressurize.
 

Nate R

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3) I don't think I have ever seen anyone do a yeast dump under pressure, I can see that having the potential to cause a real mess.

Well..
Using my Spike cf5, i usually have a little psi in the 'unitank' to help push out the sludge.. say, 0.5 to maybe 1 psi max.. No more. With no pressure, there is a small risk of suck back of oxygen via the purge valve. Also it is slow.

Also...
I have dumped at 11psi, cold. Like 40 degrees F. And yes- that was one heck of a mess. It was not on purpose. Don't do that! And if you do, clean it up before the wife gets home!
 

maddjaxx

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I dump under pressure all the time as I naturally carbonate via splunding valve. I attach a tc to hose adapter with 5 ft of hose and a 5gal bucket. Slowly work the valve to release the yeast and trub until it starts to be more liquid than trub. On my 1 bbl I do this 3 times over a few days to remove excess trub and dry hop matter. I am normally at 10 psi at 36 degrees. I put co2 back in to keep it at 10psi
 

superiorsat

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I dump under pressure all the time as I naturally carbonate via splunding valve. I attach a tc to hose adapter with 5 ft of hose and a 5gal bucket. Slowly work the valve to release the yeast and trub until it starts to be more liquid than trub. On my 1 bbl I do this 3 times over a few days to remove excess trub and dry hop matter. I am normally at 10 psi at 36 degrees. I put co2 back in to keep it at 10psi
I've got a couple side questions for you if you would be so kind. How much trub, hops and yeast would you say you dump from your 1 bbl batches on average. How much wort do you start with to end up with 1 bbl final volume on average? Thanks.
 

IslandLizard

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This post is probably not related to fermentation and yeast, I can't seem yo edit it though. If a moderator is able to move it to the appropriate section that'll be great!
Moved to Equipment/Sanitation forum. It's probably the most logical place since it's about operating equipment.

FYI, here's a another thread on using Unitanks with a similar purpose:

There are more threads on using Unitanks, you can always do a search.

BTW, you can always [Report] a post (or an associated thread) and request edits, moving, etc. so the Mods can take action on it.
 

Brooothru

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I dump under pressure all the time as I naturally carbonate via splunding valve. I attach a tc to hose adapter with 5 ft of hose and a 5gal bucket. Slowly work the valve to release the yeast and trub until it starts to be more liquid than trub. On my 1 bbl I do this 3 times over a few days to remove excess trub and dry hop matter. I am normally at 10 psi at 36 degrees. I put co2 back in to keep it at 10psi
Agree^^^

I attach a TC to 3/8" or 1/4" barb fitting. If the tank pressure is <10 psig, I don't even bother with a hose.

Just be VERY slow in opening your butterfly valve, and be ready to immediately throttle it back or close it completely if/when it starts flowing too quickly. If you open too wide or too fast you'll blow right through the trub and settled yeast, and end up only splattering good beer everywhere, leaving most of the crud stirred up and still inside the tank.
 

maddjaxx

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I've got a couple side questions for you if you would be so kind. How much trub, hops and yeast would you say you dump from your 1 bbl batches on average. How much wort do you start with to end up with 1 bbl final volume on average? Thanks.
Depends on the style but dry hopped IPA’s I will dump probably 1.5 gals of trub / yeast slurry. I usually transfer 33 gals to the unitank and end up with approximately 30 - 31 gals of beer depending on how much tasting went on before that 😉
 

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