When is spunding worth trying?

[Craiginthecorn]

Keg or bottle conditioning also has the advantage of reducing diacetyl, regardless of sugar source. Both the relatively slow fermentation and pressure contribute to this benefit.

 

[cactusgarrett]

And I can tell you from practical experience

Great - this is the stuff I like to hear. Like I said, I don't do it, but for the greater good I thought it might need to be touched on.

 

[SFC Rudy]

When I carbonate in a keg, I use half the amount of sugar as I would for bottles. Works every time. I've also used the full amount with no issues.

 

[Beermeister32]

For naturally carbonated Corney kegs, I usually use 3/4 cup corn sugar, works out to about 4.3 ounces. Heat it with a small amount of distilled or other non-chlorinated water in a pan, take a big funnel and dump it in. Purge headspace 15 cycles.

 

[micraftbeer]

At what point do you start the spunding valve process?

I spent some time staring at and fiddling with the calculations from some website that went into the science behind calculating when is the right time. The takeaway I had was there is a precise way to calculate this. But that was way more complicated than I wanted to deal with, so it seemed like when you get to the last 10% of gravity drop, you crank up the spunding pressure to around ~30 psi, and you should have sufficient sugars left for the yeast to get ~2.5 vols of CO2 (if that's you're thing) if fermenting at around 68-70F. The hardest part is really knowing what your FG will be so you can calculate when you're 10% away (yes, there's a way you can take a sample and let it ferment out on the side and measure FG that way, but that sounded like more trouble than it was worth to me).

Of course, if you spunded at 30 psi through the whole process, you won't have to worry about timing that last 10% right. There is limited info/actual test data of pressurized ferments out there, but what there is out there seems to indicate spunding at 30 psi can lead to higher ester formation. So trying to not crank up your pressure until later in fermentation might be worth it.

 

[hootowl]

The SS Brew Tech spunding valve is a one-way valve that you add Starsan to. Fill to above the line of holes in the unit and you're done. IMO, ANY spunding valve that doesn't send the CO2 through an airlock (or otherwise creates a break between the gas flow and inside the fermenter) is not worth using.

I'm using a manifold from Spike that uses the 1-1/2" triclamp. Has a gauge and a PRV. No airlock. Not sure why you would need an airlock. Doesn't the pressure keep contaminants from entering through the PRV? When it's forced to release it's releasing under pressure... like a one way valve. So are you saying that during the release, contaminants can travel in even though the pressure is pushing out?

 

[Golddiggie]

I'm using a manifold from Spike that uses the 1-1/2" triclamp. Has a gauge and a PRV. No airlock. Not sure why you would need an airlock. Doesn't the pressure keep contaminants from entering through the PRV? When it's forced to release it's releasing under pressure... like a one way valve. So are you saying that during the release, contaminants can travel in even though the pressure is pushing out?

PRV is a one way release at 14psi device. NOT to be used for spunding or fermenting under pressure. I use the spunding valve from SS Brew Tech since it's actually for spunding/fermenting under pressure where you can set it to the PSI you desire. You want to put liquid in the cup (I always use Starsan solution in mine) so that you can actually see the activity. IMO, it's also an additional layer of protection from anything going inside. Especially if you almost fill the fermenter and something gets into the works. With the models I have (CF10) I'm not putting that much into them. Even if I decide to brew a batch that's higher (~12 gallons in) I doubt I'll have anything get into the spunding valve.

 

[hootowl]

PRV is a one way release at 14psi device. NOT to be used for spunding or fermenting under pressure. I use the spunding valve from SS Brew Tech since it's actually for spunding/fermenting under pressure where you can set it to the PSI you desire. You want to put liquid in the cup (I always use Starsan solution in mine) so that you can actually see the activity. IMO, it's also an additional layer of protection from anything going inside. Especially if you almost fill the fermenter and something gets into the works. With the models I have (CF10) I'm not putting that much into them. Even if I decide to brew a batch that's higher (~12 gallons in) I doubt I'll have anything get into the spunding valve.

Thank you. I have a lot of headroom and haven't had any issues with beer getting into the PRV. I modified this valve to allow adjustability. They had it staked to one setting. I cut out the dimple that keeps you from adjusting it. I simply set it low, watch the gauge and adjust the PRV to the PSI I want. In my case using Spike Flex fermentors with the high pressure lid. I have it set at 15psi and keep a good eye on it. I'm using the Spike manifold and the domed lid which gets my PRV way up high.

 

[Jayjay1976]

You don't need an airlock when using a spunding valve.

 

[hootowl]

You don't need an airlock when using a spunding valve.

That's what I think but the higher cost ones using 1.5 triclamp have a reservoir.

 

[Jayjay1976]

That's what I think but the higher cost ones using 1.5 triclamp have a reservoir.

Can the valve pressure be set to zero? In that case, the reservoir could be so it can serve double duty as just an airlock when needed.

 

[Golddiggie]

Thank you. I have a lot of headroom and haven't had any issues with beer getting into the PRV. I modified this valve to allow adjustability. They had it staked to one setting. I cut out the dimple that keeps you from adjusting it. I simply set it low, watch the gauge and adjust the PRV to the PSI I want. In my case using Spike Flex fermentors with the high pressure lid. I have it set at 15psi and keep a good eye on it. I'm using the Spike manifold and the domed lid which gets my PRV way up high.

I'm keeping the PRV that came as part of the manifold setup as it shipped. It's why I have the adjustable spunding valve on both fermenters (I have another for when I get the third conical). With the graduations on the spunding valve I can set it at any time (even before the yeast goes in) for the pressure I want to retain. I'm going with 5-6psi lately. IME, it's enough to control the krausen, but low enough to impact the yeast less than with higher pressure levels.

Since going with the conical fermenters I've used neither an airlock nor blowoff hose/setup. Both came with the fittings to use a blowoff hose, I'm using them for other lines (on the manifolds connected to the pump heads). I actually dropped using airlocks and blowoff hoses before getting the conicals. Once I went to fermenting under pressure with the kegmenters I was using, I didn't need either.

Can the valve pressure be set to zero? In that case, the reservoir could be so it can serve double duty as just an airlock when needed.

If you really wanted to, you could. IMO, that's more of a "if needed" than "when needed" item.

 

[T Murph]

More beer offers an adjustable prv that is stainless steel for about 12 bucks that works well. Simply remove the original prv from Spikes manifold and replace it with the adjustable prv.

 

[Craiginthecorn]

The StarSan in the reservoir of adjustable PRVs (aka spunding valves) like the SS Brewtech is useful almost exclusively as a way to see gas escaping the valve. With CO2 continuously pushing out, there is virtually no chance of unwanted bacteria or other bugs getting into the fermenter. With a blow-off tube, StarSan is useful in the lag phase when there is little gas movement and later, should suckback occur, better to suck in StarSan than week-old water.

In my Spike fermenters, I don't bother with a blow-off tube. I just take a stainless 1-1/2" TC cap and EPDM gasket and place it, unclamped, on top of one of the three ports in the lid. Acts exactly as a very low pressure sounding valve.