Low dissolved oxygen brewing techniques

[dent]

Yank:yeah there are reports that this is great for almost all styles - I have only just started so if still be a while before I have any first hand examples.

Tugger: Thanks for the info - I am boiling the water to remove the DO and adding some metabisulfite to get rid of what remains. The vacuum I am using is to purge air from the grist and mash tun, and to allow me to cleanly flush out this and other vessels. I considered the CO2 removal methods like you say but I figured it would use up a prohibitive amount of gas.

 

[eldertaco]

Wow, all very interesting. There's some followup discussions linked to on the front page of germanbrewing.net too that are a good read.

One thing it says to me is that unless you take fairly extreme measures to eliminate DO right from the start when collecting your water, attempts to minimize HSA by being careful with splashing etc are going to be pretty much worthless?

If you didn't start with low DO water you're stuffed, if you don't underlet your mash you're stuffed, if you fly sparge in the presence of oxygen you're stuffed, if you boil too hard or for too long you're stuffed, and if you use any copper at all you're stuffed too.

 

[dent]

Yep pretty much. There's more than one kind of oxidation though, so I don't think there is only two effects between <1ppm and >>1ppm.

I went to some expense rejigging everything for this as per the paper, as I don't think doing half-measures is going to help anyone.

 

[wobbly]

If this is the "new way forward" it puts the argument about needing 10 to 12 ppm of oxygen in your wort via an oxygen injection system or just plain thrashing the wort with a spoon or similar for good yeast health on it's ear.

If it is on the money then maybe it is a good argument for using dry yeast that doesn't need the high levels of oxygen to kick it off.

The Williamswarn process and instructions talk about the need to keep the fermented beer away from oxygen exposure otherwise you will experience early onset of staling. This goes further in that the discussion is all about NO Oxygen Exposure

Wobbly

 

[dent]

That is not the case - oxygenation of the wort proceeds as normal, with only the added suggestion that the yeast is added before the O2. The yeast itself is quite effective at removing the DO from the wort in a reasonably short amount of time.

 

[MHB]

Wobbly
You still need to aerate at/around yeast pitching time. The yeast needs to have O2 available to reproduce, during reproduction it also removes sterols and fatty acids from the wort.
This is just as important as any other step in brewing. Thrashing at the wort isn't really very effective, if you want to something to improve your beer a good O2 kit would be to my mind a long way ahead of where this thread is focused. Healthy yeast good wort quality and temperature control all being ahead of worrying about HSA.

Dent
Have a look at N2, it really is effective at removing/excluding O2.
When I was doing Chemistry we had an old instrument called a dropping mercury electrode polarograph used to detect heavy metals (Pb Cd...) in the ppb range. Had to N2 purge all the samples or the Oxygen wave over wrote all the sample out puts - this observation lead to the development of the first compact electronic DO meters
Mark

 

[Futur]

Reading over the article and others experiences with brewing LODO has kinda blown my mind. I'd be keen to give this a shot, however I've got a copper chiller on the GF.

Just wondering if we can put an aussie spin on this method and possibly purge a cube using co2 and then no chill?

EDIT: Over at german brewing they might have stumbled on a method of removing the oxygen from mash water without having to pre boil. The method involves using bakers yeast and a small amount of DME in your mash water for about an hour. http://forum.germanbrewing.net/viewtopic.php?f=50&t=355

 

[Mardoo]

Brew In A Bag in space?

Thanks for this. One of the most fascinating topics in a while, for me. Definitely read the onward articles and forum threads. Some interesting stuff. I'm not interested in the pursuit of perfect beer, but some of the flavour issues they've mentioned are things I've seen in German-style beers I've tasted. Since I'm ostensibly on a Vienna Lager jag I'm going to keep reading.

 

[wobbly]

Wobbly
You still need to aerate at/around yeast pitching time. The yeast needs to have O2 available to reproduce, during reproduction it also removes sterols and fatty acids from the wort.
This is just as important as any other step in brewing. Thrashing at the wort isn't really very effective, if you want to something to improve your beer a good O2 kit would be to my mind a long way ahead of where this thread is focused. Healthy yeast good wort quality and temperature control all being ahead of worrying about HSA.

But does the same hold true if/when using dry yeast?

And if so can you please provide a link to some sort of reference/reading that indicates that oxygenation of the wort is required for dry yeast.

Wobbly

 

[MHB]

There is plenty around
You could start with this, just for an overview of the effects of O2. View attachment 03 - The role of oxygen.pdf
Then read the Tips & Tricks on the Fermentis website
Mark

 

[dent]

Futur: That's a good one - I had that same idea but was concerned that cooked yeast crud might not be favourable - didn't think of using baker's yeast though.

Spose you could use a cube if you really tried (I imagine I could pull a vacuum on one, it'd go back to shape with hot wort in it) but then again no chill and lagers isn't a ideal solution with DMS etc. On the plus side though the hot transfers would limit O2 uptake.

 

[manticle]

One of the main factors in that article was a rapid chill so nc/cube out of the question I'm guessing.

Not a method I'm at all set up to use but very interesting, including the info about boil length and vigour and recommended ppm of oxygen when pitching.

My understanding is that some oxidation commences as far back as malting so even this process won't prevent eventual oxidation.

Is there any indication of expected shelf life if all steps are followed and measured DO is sub 1ppb?*

*in other literature - couldn't see it mentioned in the linked article although I may have missed it.

 

[Futur]

One of the main factors in that article was a rapid chill so nc/cube out of the question I'm guessing.

Not a method I'm at all set up to use but very interesting, including the info about boil length and vigour and recommended ppm of oxygen when pitching.

My understanding is that some oxidation commences as far back as malting so even this process won't prevent eventual oxidation.

Is there any indication of expected shelf life if all steps are followed and measured DO is sub 1ppb?

But lets step back here and look at the primary purpose here for rapid chilling the wort. Their next step after the boil is to chill as quick as possible to add yeast to maintain the low DO levels.

If we manage our DO levels through the entire process up until the boil, then purge a cube with CO2 and transfer still boiling wort into a cube I don't see why this wouldn't have the same effect for managing low DO levels.

See the graph below -

Also I can't imagine storing wort for a day in a HDPE cube would allow enough gas permeability to penetrate the 1ppm O2 limit set by the paper. But someone will have to test this - with an O2 meter of course!

 

[dent]

Futur: Yeah I think you could get a cube to work from an DO perspective, it just seems a pretty slack method to use alongside a very laborious one.

manticle: I haven't seen any more data on shelf life - I too am a little disturbed about the trial it apparently is to get something good -- but it only lasting 4 weeks. Hopefully the Germans themselves have proved it is possible to keep it going for longer though.

It could be that the oxidation rate is proportional to temperature - so the 2 hours of mash time is enough to kill the malt character at, say, 2ppm, whereas at fridge temp the 0.1ppm will kill it in 2 weeks. I guess where I am leading is that perhaps DO early in the process does not cause damage in the future, it causes it now. The malt character is lost in the mash at 65 deg at 8ppm over an hour. That same malt character is lost in a kegged LODO brew at 3 deg at 0.5ppm over 3 weeks. But a LODO mash at 0.5ppm, and kegged at <0.1ppm might last much longer.

I've got one fermenting in a stainless 50 litre keg - I'll vacuum a corny dry and suck in the brew at about D-rest time - it will then be served from that same keg with no further manipulation. Hopefully the yeast will do the rest.

I'm starting to think bottle conditioning could be a very good thing for this process (zero head-space, of course!).

 

[manticle]

Be interesting to see/taste.

Futur - I guess from my perspective, I would follow everything to the letter first time, then changing other variables one at a time. You could be absolutely spot on.

 

[Futur]

Be interesting to see/taste.

Futur - I guess from my perspective, I would follow everything to the letter first time, then changing other variables one at a time. You could be absolutely spot on.

If LODO is actually a thing then the two alternate processes (mash water oxygen scavenging using bakers yeast and no chill) would possibly allow all the proposed advantages of LODO without having to splash out on an stainless steel chiller.

 

[MHB]

O2 can act in a couple of ways depending on the conditions and what else is in the environment.
One is the typical Oxidisation path think of it as slow burning where the O2 and other compounds form stable compounds, CO2, Rust...
The other is called a free radical, O2 (well an ion of) just blunders around breaking stuff up at random - and it tends to keep doing it nearly indefinitely. Does harm out of all proportion to its concentration, given time.

O2 isn't the only cause of staling, it is one of the more easily controlled. I'm far from sure that its a magic bullet, but taking care to minimise O2 up take except at yeast pitching time certainly wont do any harm, as part of a well managed brewing program, it might make the beer taste better and last longer (wont help you to keep it longer).
I wouldn't expect a miracles.
Mark

 

[Mardoo]

No miracles a'tall, it sounds. As one of the guys who did his own experiments based on the methods, inches of difference, not miles. "Inches, not even feet."

 

[dent]

Huh? That doesn't seem to be the conclusion of the article at all.

 

[MHB]

Mardo - Not a bad read, thanks.
Dent - I suspect it's going to be a case of where you are measuring from. If you are already doing most of the basics well I suspect the biggest returns are going to be in stability and shelf life, perhaps some moderate improvements in other flavours.
If on the other hand a brewer was making some pretty fundamental process errors (not that anyone on AHB would try to make beer in 2 hours, or anything like that...) then followed the steps in the OP, there is likely to be an amazing improvement in their beer. The natural inclination to ascribe the sudden improvement to LO-DO rather than to all the other process improvements is understandable, if misplaced.

In my experience if you do the basics well, you will make good beer, from there its mostly fine tuning, no seven league boots, just baby steps.
Note that minimising O2 during the whole process is just good brewing practice.
Mark