O2-ing my wort

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The difficulty comes from needing all the extra kit which needs maintenance and storage space which is an issue for those of us in units.

Whether it be intentional or not, It comes across in this thread as "pure oxygen is the only way you'll ever have success with lagers" which is demonstrably false. I'm not having a go at anyone, merely seeking to understand science rather than anecdotes.

A flowmeter, as you say, is a very rough approximation but gives repeatability. DO meters - yeah, maybe when I go pro :p

I'm not attempting to not "work" for my brewing, I don't know where you got that from. I'm merely trying to understand why people are singing the praises of pure oxygen.

No, obviously I don't eschew thermometers. That wasn't my question. I'm genuinely asking how it was done, not centuries ago, but even 40 years ago because I figured the yeast today is similar. However, the availability of oxygen was not the same then. On an industrial scale the cost of compressed oxygen would have been exorbitant back then and I highly doubt there isn't a workaround.

To reiterate - seeking to understand.

My underlying skepticism comes from trying to avoid "having to" get another bit of kit! ;)
 
Bribie G said:
Allsopp's lager brewery in London in the early 1900s fermented in closed glass-lined tanks under filtered sterile AIR pressure for the first part of the fermentation so that oxygen from the air would replace oxygen taken up by the wort. (edit, by the yeast).

Initial aeration was from wort run as a waterfall down arrays of chilled pipes into troughs where it flowed away into the fermenters.

The extra aeration could be done by opening the FV and thrashing with whisks or slotted spoons as I actually do for my Yorkshire Bitters but the O2 for me is a do once, set and forget method.

edit again: For my lagers I intend to quick chill in two lidded SS stockpots in tub full of ice water then pour into conical. That will be a smooth pour so there's going to be little agitation compared to my normal (for ales) glug and gloop transfer out of plastic cubes into FV, and way too little oxygenation.
Interesting . Thanks for the insight into The Old Brewery methods. It seems that they use the increased pressure to compensate for the reduced oxygen concentration in the air
 
You don't have to use O2, but it is the simplest way to get consistent high quality beer within the confines of what we can do as home brewers.
We tend to be under pitching, even those making starters are probably pitching at a fraction of what a commercial brewer would be using in a commercially made lager. A pitch 0.5L of heavy fresh yeast slurry per HL (100L) isn't atypical, that's something like the equivalent of 64 fresh smack packs or tubes of the two best know liquid cultures into 20L of home brew - if anyone is doing anything like that at home, well they would be the only one.

Having an acceptable pitch into a wort with the optimum amount of O2 will (this has been ignored said earlier) mean that as the yeast reproduces, and it does that until it runs out of one essential nutrient it will consume all (or most) of the undesirable wort constituents (mostly lipids and fatty acids), resulting in better attenuated more stable and enjoyable beer.

I don't see anything in Bribes post that says there was any pressure involved, bottled Oxygen has been available a lot longer than you might think, Oxy cutters invented in 1901 were widely in use in ship construction by the start of WW1 that's over 100 years ago, I suspect brewers were on to bottled oxygen PDQ as they tend to have been hot beds of technical innovation.

DO meters are out of many brewers price range, the easiest way to get a very close to target amount is to measure the temperature of the wort, over oxygenate slightly and wait 5-10 minutes before pitching. Solubility is temperature dependant and will quickly fall back to that value at any given temperature
ppm of O2 in 12oP (1.048) wort (temp/ppm of O2) 0oC/11.6; 5oC/10.4; 10oC/9.3; 15oC/8.3; 20oC/7.4
From there you can interpolate how much O2 you will have in your wort, quite accurately.

It would be easy to spend several hours extoling the virtues of O2, you can spend as long as you like finding reasons not to spend the money, just don't pretend its to make better beer.
Mark
 
klangers said:
The difficulty comes from needing all the extra kit which needs maintenance and storage space which is an issue for those of us in units.

Whether it be intentional or not, It comes across in this thread as "pure oxygen is the only way you'll ever have success with lagers" which is demonstrably false. I'm not having a go at anyone, merely seeking to understand science rather than anecdotes.

A flowmeter, as you say, is a very rough approximation but gives repeatability. DO meters - yeah, maybe when I go pro :p

I'm not attempting to not "work" for my brewing, I don't know where you got that from. I'm merely trying to understand why people are singing the praises of pure oxygen.

No, obviously I don't eschew thermometers. That wasn't my question. I'm genuinely asking how it was done, not centuries ago, but even 40 years ago because I figured the yeast today is similar. However, the availability of oxygen was not the same then. On an industrial scale the cost of compressed oxygen would have been exorbitant back then and I highly doubt there isn't a workaround.

To reiterate - seeking to understand.

My underlying skepticism comes from trying to avoid "having to" get another bit of kit! ;)
I'm sure you can do a good lager without oxygen too. I personally like to pitch a lot more yeast in my lagers also, which no doubt helps more than the oxygen. You seriously don't need that much kit to use oxygen, though, the most annoying thing is the cost of the bottles.

Anyhow I'm not sure what brewers did historically. We only discovered yeast relatively recently, so I would guess that they did nothing as they had no idea how to improve yeast metabolism.
 
Aha I got it wrong about the top pressure at the old Allsopps brewery:


It is a sign of the times and further evidence as to the growing taste for a lighter type of beer, that lager brewing in its most modern form has now fairly taken root in Great Britain, and in this connexion the process introduced by Messrs Allsopp exhibits many features of interest. The following is a brief description of the plant and the methods employed:—The wort is prepared on infusion lines, and is then cooled by means of refrigerated brine before passing to a temporary store tank, which serves as a gauging vessel. From the latter the wort passes directly to the fermenting tuns, huge closed cylindrical vessels made of sheet-steel and coated with glass enamel. There the wort ferments under reduced pressure, the carbonic acid generated being removed by means of a vacuum pump, and the gas thus withdrawn is replaced by the introduction of cool sterilized air. The fermenting cellars are kept at 40° F. The yeast employed is a pure culture (see Fermentation) bottom yeast, but the withdrawal of the products of yeast metabolism and the constant supply of pure fresh air cause the fermentation to proceed far more rapidly than is the case with lager beer brewed on ordinary lines. It is, in fact, finished in about six days. Thereupon the air-supply is cut off, the green beer again cooled to 40° F. and then conveyed by means of filtered air pressure to the store tanks, where secondary fermentation, lasting three weeks, takes place. The gases evolved are allowed to collect under pressure, so that the beer is thoroughly charged with the carbonic acid necessary to give it condition. Finally the beer is again cooled, filtered, racked and bottled, the whole of these operations taking place under counter pressure, so that no gas can escape; indeed, from the time the wort leaves the copper to the moment when it is bottled in the shape of beer, it does not come into contact with the outer air.
 
Frothy1 said:
Give this man a beer. A good succinct post with all the info one needs. Had this been posted earlier, I suspect this thread could have been stopped at 2 pages! :p
 
On Air Stones, I have tried both and use a 2um.
The 0.5um are very easy to block up, even touching it with your fingers is sometimes enough. They are so fine that when you soak them in sanitiser it doesn't penetrate into the fine pores (surface tension). The size of the bubbles from both and the rate that wort aerates is nearly the same.

I just find the 2um stones a lot easier to look after and last longer before needing replacing.

Bubble formation is interesting, as a gas flows through the pore a small bubble starts to inflate, surface tension holds it in place until it becomes big enough and buoyant enough to detach and float away. Point is it isn't really the size of the hole that determines the size of the bubble, it has a lot more to do with the density the surface tension of the liquid and the overpressure (height of liquid over the stone).
About the smallest bubble you can see is 0.5mm and you can see the bubbles that form on both stones.
Mark
 
Good point.

Probably not. Argon/helium/CO2/Nitrogen are all chemically stable and hence the regulators are all generally interchangeable. O2 is obviously not stable and often requires higher grade materials, so you risk the regulator slowly oxidising and failing.
 
Frothy1 said:
Mikeyr said:
That seems damn cheap
Frothy - that's awesome. I've already got an air stone I don't use (the little acq pump I bought never had enough oompf to get it to work), so this kit plus a little bit of beer line would be all I need. Could add in a dip tube as a gas wand...

Agreed Mikeyr, that's the best deal I seen. Does anyone know how long it would take to go through 110L of O2? It *sounds* like a lot... :unsure: ??

Happy to hear others opinions on the suitability of the regulator - would seem odd if they are selling it as a kit and the reg is not suitable of O2.
 
Depends if the 110L is at standard temp and pressure or at the supply pressure of 600kPa.
 
mofox1 said:
Agreed Mikeyr, that's the best deal I seen. Does anyone know how long it would take to go through 110L of O2? It *sounds* like a lot... :unsure: ??
The typical does rate is 1L/min for 1 min for 23L batch, so 1L per batch. So enough for 110 batches, but you will have losses so would think you should get at least 70-80 batches out of it.
 
The Italian cylinders ex Brewman hold around 95L gas volume.
 
Black n Tan said:
The typical does rate is 1L/min for 1 min for 23L batch, so 1L per batch. So enough for 110 batches, but you will have losses so would think you should get at least 70-80 batches out of it.
Cheers B&T, that's probably close to 3 years worth (for me) - although probably less if I use it on my starters too. At 50 to 60 bucks for a new bottle it's not too bad cost wise.
 
It will make a big improvement to your beers and after the initial outlay is quite economical.
 

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