Over gravity brewing, suitable water for liquoring back?

[Bribie G]

As part of my project to ferment under pressure in a cornie, I'll be brewing over gravity then liquoring back, or as CUB describe it, " adjusting to sales strength. "
That way I can leave krausening headspace in the keg but still get a full volume brew into the serving keg at the right ABV, as well as emulating commercial practice in my eternal search to brew Melbourne Bitter.

Rather than boiling then "cubing" a small batch of tank water, I'm considering just using cheap sparkling spring water - does anyone know whether it would likely contain dissolved oxygen?

 

[Jack of all biers]

Don't know for sure, but I'd suspect it will contain some O2 as I doubt they purge it before carbonation.

What about boiling your water and transferring hot to a spare keg before purging with CO2. Can then be cooled, carbonated and transfered from keg to keg without O2 contact.

 

[Lyrebird_Cycles]

Likely to be saturated with O2: it is common to ozonate water before bottling.

 

[klangers]

Yeah almost all bottled waters are ozonated. Still advisable to boil to deox.

 

[Bribie G]

Jack me old mate, you just solved my real core problem, how to get the deox water into the over-gravity beer without introducing oxygen somewhere along the line:

Bring 20L of tank water to a boil in urn.
Transfer boiling to cornie and fill it to the top.
Cool in the cornie (flush any small headspace with CO2).
Dedicate that keg as a supply of deox water just for diluting, and for each batch transfer whatever needed to the serving keg beer-post to beer-post.
Then transfer the overgravity beer using the same transfer tube.

Obviously the headspace will just be pure CO2 as the keg is used up over a few brews.
Use digital bathroom scales to indicate how many L of water transferred.
My brain just exploded.

 

[klangers]

Be reallllly careful letting hot water cool in a corny. You'll have to let it breath somehow or it will collapse the keg as the vapour condenses.

 

[Bribie G]

Thanks for the heads up. How about just putting it on fairly low CO2?

 

[MHB]

Just leave the keg connected to the gas as it cools, only need a few kPa of pressure, just enough to stop a vacuum forming and sucking in any air/O2.
Mark

 

[Jack of all biers]

Jack me old mate, you just solved my real core problem, how to get the deox water into the over-gravity beer without introducing oxygen somewhere along the line:

Bring 20L of tank water to a boil in urn.
Transfer boiling to cornie and fill it to the top.
Cool in the cornie (flush any small headspace with CO2).
Dedicate that keg as a supply of deox water just for diluting, and for each batch transfer whatever needed to the serving keg beer-post to beer-post.
Then transfer the overgravity beer using the same transfer tube.

Obviously the headspace will just be pure CO2 as the keg is used up over a few brews.
Use digital bathroom scales to indicate how many L of water transferred.
My brain just exploded.

No worries. And I'm glad the brains trust added in their two bob. Let us know your outcome with this

EDIT - I like the scales idea. Do you have a 40kg scales (eBay thread got mine for $39.) put keg on scales, tare to zero and read negative grams as mls into target keg. Will be more accurate than bathroom scales, unless yours measure to nearest 5 gm

 

[Bribie G]

Yup beat you to that one.. I just tared off a keg on bathroom scales and filled with hose to 15L then 18L to see what the rough levels looked like. The 15L level looks ideal for fermentation and a bit of krausen, then liquor back with 3 extra litres. The 18L is just below the gas post.
When I get to the liquoring back stage in 3 weeks or so (with an Aussie Lager fermenting schedule) I'll need to have a more accurate scales for sure.

Getting a bit off topic, assuming it all works out, I'll try to put up a thread with pics to merge the elements of over gravity brewing, fermenting under pressure and oxygen free environment. Plus calculations for O.G. brewing (getting onto that now).

I'll be able to use my Crown 20L urn for the boil as well, bonus as it hasn't had much of a workout recently.
I recently bought a spunding valve and just cannibalised a bronco tap to make a beer to beer transfer line so pretty well good to go.

And going right off topic: Tidal Pete if you are reading this, your dipstick you engineered for me is going to be the ducks' nuts for accurately controlling wort levels in mashing and boiling - might have to desecrate it with a couple more line scorings

OK off to get my coat.

 

[DaveGillespie]

I've been toying with the idea of a LODO brew and the guys on their forum have developed a method of deoxygenating water with a tiny amount of bakers yeast & sugar.

http://www.lowoxygenbrewing.com/brewing-methods/yeast-deoxygenation-method/

Seems this might be suitable for liquoring back post-fermentation as well. Do a water purge of the serving keg, but leave as much water in it as you require for liquoring back. Add a small amount more water with the yeast and sugar required for the total volume into a PET bottle with a carbonation cap, purge then gas up to say 30 PSI then transfer this to the serving keg with a jumper cable. Leave the yeast to work for an hour to consume all the oxygen in the water then pressure transfer from the fermenting keg into the serving keg and you should have a full keg at desired gravity.