Oxygenation rate of still water - preboil mash/sparge water the night before? (LODO)

[scone]

Can’t seem to find the answer to this anywhere. If I boil my mash/sparge water the night before I brew, and let it cool off naturally on the stove (not in an air tight container, just in the stainless stock pot), how much oxygen will it pick up from the air over ~12 hours?

I want to borrow some techniques from the LODO brewing community but boiling and chilling right before I need it is just not something I want to delve into right now. I do no-chill and anyway I’m not dying to spend the $$$ on a stainless immersion chiller at the moment… not to mention how much time it would add to my brewery.

So I’m wondering, is this an acceptable substitute to boiling and chilling the water right before use from a LODO brewing perspective or would I just be wasting time and energy if I did it this way? The equilibrium O2 concentration of 60 degree water is around 8-9ppm I think, would I be way less than that if I pre-boil the night before, right?

 

[stamandster]

Techbrau has the right idea

 

[jerbrew]

I don't do LODO brewing but from a thermodynamics standpoint, you'll probably be wasting your time. Without being able to isolate that water from the environment you'll have oxygen dissolving into the water as it cools and sits there. I don't know what the requirement for LODO water is but allowing it to cool and sit around even at atmosphere will allow oxygen to integrate back into the water. If you could keep the water as warm as possible by maybe putting it into a cooler (like if you use a cooler mash tun) and closing it off with some suran wrap and the lid might mitigate the amount of oxygen reintroduced. Good luck.

 

[techbrau]

Almost no oxygen would reintroduce itself into the water on its own. Really in that time period only agitation or force oxygenation would add oxygen to the water in noticeable quantities.

That isn't true.

You will get ~1 ppm per hour diffusing into ~5 gallons of water in a bucket.

You can buy or borrow a DO meter and confirm this for yourself (I have).

Gas always dissolves into liquids at a rate proportional to the surface area of the gas/liquid interface. The reason splashing dissolves gas into liquid faster is simply because it creates more surface area.

Preboiled water left exposed to the atmosphere overnight will be back up at whatever its oxygen saturation level is at the temperature it's kept at by morning.

 

[stamandster]

That isn't true.

You will get ~1 ppm per hour diffusing into ~5 gallons of water in a bucket.

You can buy or borrow a DO meter and confirm this for yourself (I have).

Gas always dissolves into liquids at a rate proportional to the surface area of the gas/liquid interface. The reason splashing dissolves gas into liquid faster is simply because it creates more surface area.

Preboiled water left exposed to the atmosphere overnight will be back up at whatever its oxygen saturation level is at the temperature it's kept at by morning.

Your right, I wasn't thinking

 

[scone]

Hmm, ok scratch that plan then. Great info, thanks all!

I could boil exactly 7.5 gallons and fill an empty pony keg up all the way and seal it. Would still save me the hassle of pre-boiling and chilling on the morning-of, and I could rack the cooled water out with a siphon to minimize splashing and heat to mash temps. It's a little bit less attractive but it would be a cheap way to try a LODO-ish brew without investing in things I don't have...

 

[ajdelange]

You could try putting the lid on the pot and shooting some CO2 in under it. This won't solve the problem completely as you won't be able to purge all the air and eventually more will diffuse in anyway but it ought to help.

 

[stamandster]

If you boiled and put it in a container you could pull vacuum and seal its then o2 wouldn't be able to diffuse back in? Just theory of course.

 

[Beermeister32]

You could transfer it to a corney keg, and purge the headspace. That would isolate the preboiled mash water from picking up O2. If you were really into it, you could underlet your mash grains by rigging a hose between the keg and the outlet valve in your mash tun and transfer it with a CO2 bottle.

 

[daveMN]

Float a cake pan or put foil over the surface of the water post-boil to minimize the surface area. Easier yet, look up yeast oxygen scavenging. Basically, 2 grams each of dry active bread yeast and table sugar in your strike water. It knocks the DO down to 0 in under an hour, and I've left it overnight with good results. Either way gets it done without a lot of effort.