Purging

[Agentgonzo]

.in industry when dealing with CO2 you have to be aware of CO2 settling to the bottom of vessels.

You do, but this is normally because the CO2 is produced at ground level and can stay there (rather than settling out) if there is not enough air currents/ventilation to mix with the air.

 

[hoppyscotty]

oh well...makes me feel better about it anyway...but I guess with each purge you're increasing the concentration of C02. There must be a level of oxygen where it becomes good enough. I've had hoppy beers in my kegs for many months that still don't show signs of oxidation after the starsan method of keg purging so a viable method - in fact got a really hoppy beer I'll probably finish off tonight thats been in the keg since August or early September and still tastes fresh. Lost some of its hop aroma to keg headspace unfortunately but still a nice drop.

 

[Agentgonzo]

but I guess with each purge you're increasing the concentration of C02.

Correct

There must be a level of oxygen where it becomes good enough

There will be. I have no idea what level that would be, and "good enough" is so subjective that it'll vary from person to person.

 

[Agentgonzo]

in fact got a really hoppy beer I'll probably finish off tonight thats been in the keg since August or early September and still tastes fresh.

Then your process sounds "good enough" to me

 

[foxy]

And what about my method for venting the keg for ten seconds at 30 psi? Is there any way to calculate the amount of oxygen that remains?

Here is the chart of how much CO2 it takes, at what PSI and how many cycles it takes to purge a keg.
Breweries shoot for 0.5 ppm as acceptable level.

 

[hoppyscotty]

Wow that’s a handy chart. There is a chart for everything in this hobby!!

 

[phildo79]

Wow, that is a lot of purging and just for the headspace. So should I not be too concerned about purging before transfer and instead focus on purging the headspace when transfer is complete?

 

[hoppyscotty]

Well if you're transferring into an already purged keg via the starsan method then there will be no need to purge after transfer.

 

[phildo79]

So does that chart refer to the oxygen content in the headspace after transfer and after using the StarSan method?

 

[Agentgonzo]

So does that chart refer to the oxygen content in the headspace after transfer and after using the StarSan method?

Headspace after transfer
The oxygen content after the starsan method is essentially zero.

 

[foxy]

So does that chart refer to the oxygen content in the headspace after transfer and after using the StarSan method?

No, that is just purging with CO2 That chart is before adding the beer to the keg.
A good forum for those looking to reduce oxygen from their brewing is this one.
https://www.themodernbrewhouse.com/...rging-transferring-stabilizing-finished-beer/

 

[Branny]

As a returning brewer I quickly moved to the Starsan method after my first keg brew was rancid. I only Co2 purged the keg a few times - it was clearly oxidized after conditioning.

Starsan method with gas bottle and I've never had the problem since.

Just today I've started my first Starsan purge with fermentation gas and I've no doubt it'll be fine.

 

[foxy]

As a returning brewer I quickly moved to the Starsan method after my first keg brew was rancid. I only Co2 purged the keg a few times - it was clearly oxidized after conditioning.

Starsan method with gas bottle and I've never had the problem since.

Just today I've started my first Starsan purge with fermentation gas and I've no doubt it'll be fine.

You can get none foaming Starsan or better still PAA. Because hop compounds oxidise easily will add to the oxidising of the beer NEIPA springs to mind with AIPA's coming second. As in the article from The Modern Brewhouse temperature, movement and how quickly a keg can be consumed is all relative. I would say kegs wouldn't last more than a month, (mine wouldn't.) so most folk wouldn't have a problem type of beer dependent and care taken.
If one really wanted to get serious about keeping out the O2 then drinking straight from the fermenter would be the go, there would be very little if any oxygen in there.

 

[AJA]

If you don't want to use starsan, you can just use water. Solves the foam issue then. Obviously boiling water would be ideal, as dissolved oxygen is zero near 100°, but safety means this isn't worth it. It doesn't stay in the keg long enough to diffuse out into the headspace.

On the purging cycles, this table is useful for example when dry hopping, prior to a closed transfer. 5 purges at 30psi is plenty, and will use about 20l or around 40g of CO2. The same as purging an entire keg with the starsan method.

The 0.5ppm target for breweries is dissolved O2. This does not translate to the same value in the table as oxygen is rather insoluble indeed.
E.g 210000 ppm (air) in the headspace will lead to 8ppm in the beer at 25°C. or 12ppm at 5°c
To get to the ideal 0.1ppm you therefore need to get O2 in the headspace to 210000/120 =1750. (Which tallies very nicely with the 5 purges at 30psi rule of thumb :) )

 

[hoppyscotty]

Or SMB water solution. I’ve done both methods and starsan purge works fine and is just more convenient and works fine with hoppy beers lasting in the keg. Though like the idea of purging from a fermenter. I wonder how many kegs you could purge from a typical fermentation. Maybe daisy chaining a few kegs together?

 

[Agentgonzo]

Or SMB water solution. I’ve done both methods and starsan purge works fine and is just more convenient and works fine with hoppy beers lasting in the keg. Though like the idea of purging from a fermenter. I wonder how many kegs you could purge from a typical fermentation. Maybe daisy chaining a few kegs together?

Quite a few. I think that each 2 gravity points give you a volume of CO2 when fermented. So a 23L batch that ferments out through 30 gravity points would give you over 300L of CO2. Some of that will dissolve in the starsan, but you can easily purge a few kegs no problem.

 

[phildo79]

Decided to try daisy-chaining another keg to the FV to let fermentation do the job for me. Brew day was Tuesday. Today is Thursday. No sign of any bubbles in the blow-off bottle. Both kegs are airtight. Wonder how long it will take before I see some activity.

 

[phildo79]

Well there eventually was sign of activity. Not massive but it was there. Transferred last night but there seemed to be a lot of fluid sloshing about in the purged keg. So I opened it. Glad I did. There was a lot of expelled wort and trub. I had to clean it and re-purge before transfer.

Now, I ferment in a 23L corny so with only 3L of headspace on this brew, that has caused this issue. If I had more headspace, that probably wouldn't have happened. So I wouldn't try it again with this recipe but would have another go if I ended up with more headspace.

 

[Hazelwood Brewery]

Here’s one way to reduce oxygen

 

[Rodcx500z]

Here’s one way to reduce oxygen

View attachment 80825

Is that beer H, if so i take it you have a check valve on your gas line