Low dissolved oxygen brewing techniques

[klangers]

That makes sense. Please bear with my paraphrasing - it helps me understand.

Metallic copper oxidises to copper oxide (a variety depending on oxidation state and other conditions). When in contact with acidic wort, the copper oxides dissolve and disassociate to the ions. The ions then catalyse a reaction with dissolved oxygen in the wort to create more damaging compounds.

The key point for me is that it is not the copper alone that is the issue. It's when you have copper gear AND DO in your wort. If you have low DO, the copper ions can't react with the oxygen to form the more damaging compounds.

Therefore, in theory, one should be able to have copper gear so long as DO is eliminated as far as practicable.

 

[Adr_0]

CuO, which is all but insoluble in water, is soluble in acidic solutions. It will form 'free' Cu++ ions, the oxide anion results in a water molecule. This is not a redox reaction, simply copper ions dissolving, no oxidation/reduction takes place. The Cu++ ions now become available to redox catalyse any dissolved oxygen to the more reactive compounds I've already discussed (superoixde, hydrogen peroxide, hydroxide radicals).

As I mentioned previously, when Cu ions interact with O2 they do not form the oxide (CuO). What you are thinking of is the surface reaction between an elemental metal and oxygen which produces the metal oxide - it is a 2 electron oxidation/reduction - copper goes from 0 to +2, oxygen goes from 0 to -2. This is metal in the elemental oxidation state of 0, not +1 and +2 which is what they are in solution.

...and there we have it. Thankyou sir.

I guess then that CrO/NiO will not as readily dissociate in pH 5-5.5 as CuO?

 

[Lyrebird_Cycles]

 

If only the vacuum pumps being thrown out at work weren't 3 phase...
 

 

An old 'frig compressor works perfectly well as a vacuum pump; best get one where the refrigerant has already leaked out, otherwise you have to dispose of it.

That being said I prefer to use a dedicated single stage vacuum pump but then I'm running mine for hours on end (composites in a curing oven).
Google image search "vacuum bagging pump"

 

[klangers]

  

An old 'frig compressor works perfectly well as a vacuum pump;

Excellent! I'm not short on those

...and there we have it. Thankyou sir.

I guess then that CrO/NiO will not as readily dissociate in pH 5-5.5 as CuO?

Not so much nickel oxide (nickel is very difficult to oxidise and is considered corrosion resistant).

But chromium is passivating, and oxidises readily in air to form a durable protective oxide layer.

Basically the more reactive the metal, the more stable its oxide is. Sodium chloride comes to mind as a classic example

 

[neal32]

FWIW I'm doing my first lodo brew this weekend and have been devouring information and podcasts relating to oxygen ingress on the hotside. In particular there are a couple of Charlie Bamforth podcasts that were quite interesting. The take away points were that HSA was of little to no importance and he even mocks anerobic brewhouses more than once. He also tells a story of himself improving Carling Black by decreasing the oxygen pickup and the customers sending it back because they preferred the staled one. Along the same line he has done blind experiments with fresh and staled beer with 50% of the people preferring the staled beer. So for the people who practice LODO to say it makes the best beer is purely subjective.

One thing that was unanimous was that oxygen at any point after fermentation was completed was detrimental to flavour stability. Which is cool because the brew this weekend will be the first one that is transferred to the serving keg without the slightest hint of oxygen. I am using a spunding valve and connecting both serving kegs and my filter inline so they will be flushed with natty co2 for 2 weeks! Should be fun to compare the differences.

 

[Futur]

FWIW I'm doing my first lodo brew this weekend and have been devouring information and podcasts relating to oxygen ingress on the hotside. In particular there are a couple of Charlie Bamforth podcasts that were quite interesting. The take away points were that HSA was of little to no importance and he even mocks anerobic brewhouses more than once. He also tells a story of himself improving Carling Black by decreasing the oxygen pickup and the customers sending it back because they preferred the staled one. Along the same line he has done blind experiments with fresh and staled beer with 50% of the people preferring the staled beer. So for the people who practice LODO to say it makes the best beer is purely subjective.

One thing that was unanimous was that oxygen at any point after fermentation was completed was detrimental to flavour stability. Which is cool because the brew this weekend will be the first one that is transferred to the serving keg without the slightest hint of oxygen. I am using a spunding valve and connecting both serving kegs and my filter inline so they will be flushed with natty co2 for 2 weeks! Should be fun to compare the differences.

I'll be interested to see how you go. I've done two LODO batches now with the first a failed attempt due to horrible efficiency issues. I did a no sparge grainfather batch with 35% efficiency. The next batch I fly sparged and got 55%. I normally hit about 72-75%. Either the SMB or malt conditioning is affecting my mash. I'll be watching to see how it turns out for you

 

[Chridech]

I'll be interested to see how you go. I've done two LODO batches now with the first a failed attempt due to horrible efficiency issues. I did a no sparge grainfather batch with 35% efficiency. The next batch I fly sparged and got 55%. I normally hit about 72-75%. Either the SMB or malt conditioning is affecting my mash. I'll be watching to see how it turns out for you

I am really interested Futur to learn how you went about trying LODO with the GF. It's something I have been thinking about a lot. Specifically how did you mash in and sparge? These seem to me to be the most obvious processes for introducing 02 using the GF. Did you try anything different during the mash recirc. to minimise oxygen ingess or just rely on the SMB to do the scavenging? Did you no-chill or use an alternative non-copper chiller? I've been following this thread and the source documents with great interest. I want to give LODO a go but am rather pessimistic I can achieve it on the hot-side with the GF.

 

[Futur]

I am really interested Futur to learn how you went about trying LODO with the GF. It's something I have been thinking about a lot. Specifically how did you mash in and sparge? These seem to me to be the most obvious processes for introducing 02 using the GF. Did you try anything different during the mash recirc. to minimise oxygen ingess or just rely on the SMB to do the scavenging? Did you no-chill or use an alternative non-copper chiller? I've been following this thread and the source documents with great interest. I want to give LODO a go but am rather pessimistic I can achieve it on the hot-side with the GF.

My method so far is this (not proven!):


I pump starsan solution through the CF chiller and let it sit until it gets used later.
I treated the mash water with bakers yeast and dextrose in the grainfather and let it sit for 60 minutes (http://forum.germanbrewing.net/viewtopic.php?f=50&t=355)
I then condition the malt with about 1.5% water by weight, waited about 20 minutes and then milled directly into the grain basket.
I then added 100mg/L of SMB to the mash water once it was at about 50C and carefully stirred it in. I let it sit for about 10 minutes to do it's work on the remaining dissolved O2.
I lowered the grain basket slowly into the mash water until all the water under-let through the grain.
I then put the top plate and lid on and started the pump, adjusting the flow rate to ensure the re-circulation outlet was under the mash water but not without mash water running down the overflow.

From here you could either sparge or no chill, my first batch was no chill but due to the huge efficiency hit from doing it no sparge I think that will be used for canned starter wort. No chill will be something I'll experiment with later until my process is more sound.

The sparge is the riskiest part and from what other grainfather users who have provided DO readings state that they still manage < 1.0ppm of DO after the sparge but it's close. When sparging ensure the sparge water has been pre boiled and treated with SMB at the recommended dosage of 20mg/L. There is no avoiding splashing of the wort here unless you have some sort of skyhook where you can lift the basket slowly and support it to minimise splashing. Otherwise sparge as normal.

Chilling is an issue for most of us (down to 6C!), an esky and pond pump with chilled water/ice/salt is about the only option I believe. Also when chilling you'll want to recirculate and chill using tap water until you can get the temperature down as low as possible, this however wastes a lot of water!

My next batch I'm going to attempt a BIAB in the grainfather and go no sparge to reduce the O2 risk. I'm also going to reduce the amount of SMB used (50mg/L) and also use Brewtan B in the mash (http://forum.germanbrewing.net/viewtopic.php?f=46&t=356&hilit=brewtan)

This is where I'm going with this but I'm really flying blind without a DO meter. Feel free to point out any ways to do this better than I already am

 

[Chridech]

Thanks Futur for your detailed reply. Impressed by your dedication. I wondered whether anyone local was using baker's yeast for O2 scavenging pre-mash. Interesting thread on the German brewing forum detailing it.

When you lower the mash tun into the boiler do you also gently stir the mash to ensure there are no pockets of trapped air? Or does pre-conditioning the grain reduce the likelihood of air-pockets? Any benefit of filling the boiler with CO2 before lowering the mash tun?
When sparging, until now, i have poured In the sparge water with a 5L jug. Guess it would be worthwhile pumping or gravity feed the sparge water with a hose from the sparge water heater in similar way you describe for the recirc. during mash. Agree with you that elevating the mash tun and letting it drip into the boiler is the most at-risk part of the process. A winch to slowly lift the mash tun to the level of the boiler wort-level could be helpful, as you say. I need to look up your link on Brewtan B. Cheers Futur, thanks for your efforts.

 

[Lyrebird_Cycles]

This is where I'm going with this but I'm really flying blind without a DO meter. Feel free to point out any ways to do this better than I already am

You don't need a DO meter to measure DO, you can do it with methylene blue dye.

The basic technique is to add barely anoxic methylene blue to the sample and visually compare the colour development against a known standard.

The tricky bit is taking the sample without altering DO2 status but it can be done. If you are interested I can provide excruciating detail.

 

[Mardoo]

Oh, do go on...

 

[Futur]

I would love to hear how to do this! Please provide the excruciating detail!

 

[Lyrebird_Cycles]

OK, I've had a go at writing this up but I have to admit that it's not the easiest thing to follow. If I get time in the next week or so I might do one of these and take pics and post it up as a separate thread.

Materials:

Methylene Blue
Reducing agent: Sodium dithionite (best) or sodium ascorbate / ascorbic acid.
8-10 small clear glass bottles all the same size, preferably with rubber lined metal caps. McCartney bottles work.
Soft rubber sheet approx. 3mm thick if your bottles don't have rubber cap liners.
Small graduated syringe with sharp needle.
White diffused light source (a backlit sheet of paper works)
Scales and glassware to do reasonably accurate sample make up and dilutions.
Some method of inerting the sample bottles.

First convert two or three of the sample bottles to make them injectable. If your bottles have rubber lined metal caps, remove the rubber septum, cut a hole in the top of the bottle cap then put them back together. If your bottles don't have rubber septum make one by cutting a rubber disc that just fits into the bottle cap and screw the cap down onto the bottle so it holds the rubber septum in place. Another method is to bond a rubber septum to the outside of the cap and punch a hole through both with a small nail.

Make up some methylene blue solution at 5 g/l. Keep half of this aside for the injecting solution. Use some of the rest to make up standard solutions in six of the sample bottles (not the ones you made into injectable bottles) by serial dilution.

Conveniently, methylene blue has 10 times the MW of O2 so standards for say 0.25, 0.5, 0.75, 1, 1.5, 2 ppm O2 are 2.5 to 20 ppm methylene blue. Label the standards on the top of the bottles, not the sides. Fill another two bottles with plain water, label these as zeros.

Now for the tricky bits: taking a sample without adding oxygen and injecting the dye.

Your best chance of taking an oxygen free sample is to completely fill the bottle with inert gas first. Argon is best, CO2 and nitrogen work OK. At a pinch you could use a sodastream or even the gas coming off an active fermentation. Sample slowly so as not to entrain oxygen as the sample fills. Take at least two samples and use the one you did the worst job on as the blank (see later).

If you are taking from a sample tap, put a short flexible hose on the tap first, start the flow out the hose and then drop the hose into the bottom of the bottle. Hold the cap next to the mouth of the bottle so the inert gas coming out of the bottle fills the cap. Lower both bottle and cap as the bottle fills and cap the bottle as soon as you reach the end of the hose.

If doing a top sample, hold the bottle at a shallow angle and push it into the fluid until it starts to fill (slowly) and keep lowering until it’s full. Do the same with the cap and put the cap on the bottle whilst both are under the surface.

To make the injecting dye, take some of the methylene blue you set aside and add reducing agent to it until the blue colour just disappears (should be pale yellow). If you’ve got this right, you’ll get a faint blue tinge when you suck it up into the syringe. If it goes solid blue you are getting entrained air, you need to fix that before proceeding. If it stays completely yellow you’ve gone too far, push it back out the syringe and do it again until you get the blue tinge.

Making sure there is no air in the syringe, push the needle through the septum and inject dye: approximately 1% of the sample volume. Mix until the colour is uniform.

So now you have an injected sample, a blank sample, a couple of zeros and a range of standards. Place one of the zeros in front of the light source and your injected sample in front of that. Place one of the standards next to the zero and the blank sample in front of that. Stand back and look through each pair of bottles towards the light source and compare the colours: if the standard is lighter, swap it out for the next higher, if darker swap it for the next lower.

Voila, DO2 by wet chemistry. It should be obvious that this works best on pale fluids.

 

[neal32]

First LODO brew done. A few things would have disqualified me from doing a GBF certified brew. I used a real wort porter starter for the first step of my yeast starter, I used a copper HERMS and CCFC, did a short rest at 55 to dough in below gelatinization, only treated the water to 20mg/L of SMB and I didn't measure o2 throughout the process. I also used the yeast oxygen scavenging method and it was indeed strange doughing in with yeasty water.

The wort tasted as good as it usually does, without doing a side by side I couldn't confidently say that the LODO one was better. There was however a lesser smell at dough in and at the boil the wort looked like it did early on like it does after I add whirlfloc/koppafloc, maybe it's a coincidence or that the wort was lighter coloured but it did seem to coagulate better. Brewhouse efficiency was the approximately the same @ 82%. I was hoping for better seeings I tightened the mill up to .032 from .038. But on malt conditioning the crush was a lot better and it will be something I'll keep doing. It seemed to ramp to temp quicker on the HERMS as well, although I didn't time it.

I'll let everyone know how it turns out in a month or so. I'm going to do a primary at 13 degrees @ 15 psi and then lager at 4 degrees for a 3-4 weeks. Then I'll knock out a LODO munich dunkel on the cake.

 

[Futur]

Thanks Futur for your detailed reply. Impressed by your dedication. I wondered whether anyone local was using baker's yeast for O2 scavenging pre-mash. Interesting thread on the German brewing forum detailing it.

When you lower the mash tun into the boiler do you also gently stir the mash to ensure there are no pockets of trapped air? Or does pre-conditioning the grain reduce the likelihood of air-pockets? Any benefit of filling the boiler with CO2 before lowering the mash tun?
When sparging, until now, i have poured In the sparge water with a 5L jug. Guess it would be worthwhile pumping or gravity feed the sparge water with a hose from the sparge water heater in similar way you describe for the recirc. during mash. Agree with you that elevating the mash tun and letting it drip into the boiler is the most at-risk part of the process. A winch to slowly lift the mash tun to the level of the boiler wort-level could be helpful, as you say. I need to look up your link on Brewtan B. Cheers Futur, thanks for your efforts.

Sorry Chridech I forgot to respond to your message earlier!

Yeah I do gently stir the mash to ensure the grain is fully mixed with the water. I don't think purging with CO2 makes a lot of difference due to the mixing of air and CO2, it takes a lot of CO2 to fully purge a volume of oxygen. I've always sparged with an urn sitting higher than the GF and adjusted the output ball valve on the urn to control the rate of sparge to maintain the correct level above the top plate.

To be honest I think the best way is to no sparge in the grainfather. I've tried no sparge by mashing using the recommended mash water amount and then just adding the sparge water (boiled + SMB treated) directly to the batch after the mash which gave me horrible efficiency (35%). I believe the best way would be to do a full volume mash with either the basket or a BIAB bag. I'm going to try this next.

 

[dent]

Well the first brew on LODO is on tap now. I think it still has some of that great aromatic nature but it has diminished a lot - but that was expected, the cold side process still needs some work. Gotta say this must be one of the palest beers I've ever brewed. The other problem is I think I can pick up the sulfites in the beer - I did add some more to the grist so I'm not particularly surprised. Bit hard to describe what the sulfites give me - reminds me of cheap BUL cider.

The second brew is even worse sulfite wise. Apart from that it's pretty much the same. It could be my vacuum process doesn't consume as much sulfite as expected, or I'm just overdoing it. Either way I'm gonna back that off a lot next time. I'll also try it no-sparge as well - this is to mainly shorten the brew day with the process - I'm happy to sacrifice another kilo of malt to efficiency if that's what it takes.

All in all it's promising, and I'm going to continue the experiments. I'll address the cold side more thoroughly in particular.

By the way, the smoked porter LODO came out great - though I can't pin that medal on the LODO process, it might have been just as good anyhow. Can't pick any sulfites in that one, though it is black and all.

 

[Adr_0]

Something i was thinking about with dosing SMB/ascorbic acid...

The earlier graph really represents maximum DO for a given temperature. If we are boiling strike and sparge water - mixing it thoroughly while boiling - we should have 0ppm.

It's only if we mix/aerate the entire volume at 65°C that it would then come up from 0ppm to potentially 4ppm (probably less given the water is now a solution of sugar and minerals). So inversely if this is sitting static, even after a few hours the average ppm is probably a fraction of a ppm.

So I was leaning towards dosing for 1ppm with SMB, so 5-7mg/L, with the following:
-CO2 flush of piping and air space over kettle > will reduce O2 uptake potential in water
- CO2 flush of mash tun, dose SMB/ascorbic into mash tun, fill with water, mill straight into mash tun with low pressure CO2 going through mill chute
- 20-25L drum set up for sparge water, CO2 flushed and with SMB dose in the drum. This then plumbs directory pump suction header when I want to use it.
-any wort transfers done with CO2 purge on transfer line.

Still putting everything together, but these are some fittings I've gotten:
https://www.brewhardware.com/product_p/fflbarb12.htm
https://www.brewhardware.com/product_p/flarem14xflarem14.htm

1/4 SAE female flare are common for CO2 and what i have on my regulator. There are also 1/4 valves and caps on ebay to shut off CO2 flow and lock in CO2.

For my mash tun and kettle i have bored holes with 1/2 silicone hose that these barbs can fit in, and similarly couple up to barb tees for transfers.

 

[neal32]

This is my lodo helles. Its a very nice beer if not a little too sweet for my tastes. I'm not sure if the lodo is responsible for it being a good beer though. I'm about to keg up a munich dunkel done the normal way with the same yeast (2308). It's far from a perfect side by side but it will be interesting none the less.

 

[pajs]

Great thread. Lots to think about, especially as my four favourite styles are Helles, Kolsch, Pils and Alt. Interesting to think what a full-volume BIAB version of the article's suggested process would look like.

 

[Adr_0]

So these arrived today from the US.

It was basically 10 days from the US to non-metro Qld.

Should be very handy for flush/purge points.