Low dissolved oxygen brewing techniques

[wobbly]

A quick search brings this topic up as the only topic on LODO subject on AHB with the last posts being a couple of months ago so I was wondering if there have been any more recent updates by those following this methodology/experience.

While on the subject of LODO wouldn't any kit beer manufactured/produced in a modern brewery have most if not all of the implied benefits due to brew water being degassed, grain wet/moist milled/crushed, malt added to the mash tun under inert conditions via some sort of flooded screw feed etc. and then boiled under vacuum conditions. Fermenting these beers under pressure and controlled temperature with NO exposure to oxygen from the commencement of fermentation through to consumption would appear to offer close to a beer that is oxidation free provided you liked the kit and how you might pimp it.

I acknowledge that in general kit products are not every ones cup of tea (and I don't currently use them instead producing fresh wort in a 20lt Braumeister) as they are constrained by the makers recipe with respect to grain bill and hop schedule.

Cheers

Wobbly

 

[good4whatAlesU]

Does ultrasonic cleaning drive out gas from liquid (including oxygen?)

I've just emailed these guys: http://m.ebay.com.au/itm/251576795594

In the interest of getting one of these as a mash vessel, mainly for the temperature control function (to do step mashes etc). But maybe the ultrasonic function could be used to drive O2 out of the mash water?..

 

[dent]

It would probably help if it was under vacuum as well.

 

[MHB]

Ultrasound is a pretty good de-gasser, but following the link, the biggest one they give specks for is the 15L model and the heater is only 360W, so it might work as a mash tun but not as a kettle. The other point worth thinking about is that I for one have no idea what ultrasound would do to enzymes, they can have some interesting effects including emulsifying oil/water.
Be worth doing some serious research.
Mark

 

[Adr_0]

I was going to suggest mash tun too, but for its ability to break down the grain and get good extraction efficiency.

Temps used end up much lower. I'll dig up the article in a few hours.

 

[good4whatAlesU]

30L example appears to have 800W - and good up to 80 degrees C.

http://www.ebay.com.au/itm/Digital-Ultrasonic-Cleaner-Stainless-Steel-Heater-Timer-Industrial-30L-Tank-/331604576007?hash=item4d352c4707:g:KkEAAOSw5cNYP~8B\

So would be fine for mashing and temp control (not boiling). Ultrasonic can be simply turned off if that's not useful (agreed some further research would be interesting).

I've sent them an email, I'd like to see the drainage port (inside the SS tray) and see how low it is placed, and /or how hard it would be to cover with a false bottom or/ attach bazooka tube or equivalent. It looks like a brass ball valve so I'd also like to know how hard it would be to replace with a cleanable valve.

Given that some SS mash vessels (with no temp control at all) are up around $400 and above - this unit could be an okay option. Depends on quality. How much have to spend on getting it set up. .. etc.

Edit: here's a 20L one (looks like there are a heap of them coming out of China), possibly same factory and re-branded:

http://www.ebay.com.au/itm/New-20L-Digital-Ultrasonic-Cleaner-Stainless-Steel-Heater-Timer-Industrial-Grade/162266552121?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D2%26asc%3D39923%26meid%3Ded728c04fd4f466c96274260676de8c9%26pid%3D100005%26rk%3D5%26rkt%3D6%26sd%3D112000845383

 

[klangers]

Interesting.

I can almost guarantee that the heating elements are unsuitable for wort - too high a power density.

Another possibility is installing an ultrasonic transducer into a "normal" mash tun. The transducers can be had for ~$30 for a 100W one. This may be a cheaper way of experimenting with any conversion efficiency enhancement effects.

 

[MHB]

Or the reverse, quite possible that ultrasound will denature enzymes, or do a lot of other unexpected things.
Mark

 

[good4whatAlesU]

Thanks Klangers, bit of a bummer about the heat elements. .. Although it only needs to maintain temperature (if the mash water is pre-heated) and/or change a couple of degrees to step up - it might be sufficient?

Perhaps a quick lit review in Google scholar (or such) might turn something up about the impact of ultrasonic on enzymes.

PS. could not the mash water be de-gassed before the grain is added? Hence having no effect on the enzyme activity? (edit; although adding the grain will also introduce oxygen, but not at least it will be reduced?).

 

[Adr_0]

http://arxiv.org/pdf/1609.06629v1.pdf

Regarding de-aerating, ultrasonic agitation/cavitation actually oxygenates the wort. Keep in mind agitation will bring water/wort to its DO equilibrium point, which is 0ppm only at 100°C, and 2-15ppm at temperatures less than this. So at mash temps you will possibly be sitting at 4ppm or so... Unless you did everything under an N2/CO2 purge/blanket.

 

[klangers]

http://arxiv.org/pdf/1609.06629v1.pdf

Regarding de-aerating, ultrasonic agitation/cavitation actually oxygenates the wort. Keep in mind agitation will bring water/wort to its DO equilibrium point, which is 0ppm only at 100°C, and 2-15ppm at temperatures less than this. So attractive mash temps you will possibly be sitting at 4ppm or so... Unless you did everything under an N2/CO2 purge/blanket.

Great link.

Had a quick read - they are using a rig that generates hydrodynamic cavitation via a venturi and 7.5kW (!) circulation pump. This is a lot more violent than the vibrations found in ultrasonic cleaners, and not really comparable. Ultrasonics don't necessary cause cavitation, but cavitation always causes ultrasonic vibrations and pressure waves.

I didn't see any reference to DO, and I'm not sure how cavitation would, or could, cause aeration (help me understand). Cavitation is the localised reduction in pressure of a fluid to below its vapour pressure, formation of said vapour bubbles, and consequent rapid collapse. In the case of wort, this would be the formation and collapse of, effectively, steam. Not air. Nothing is going in or out of the fluid.

The paper is very positive about the efficiency of the cavitation process. However, the mechanism for this is simply an improved mass transfer rate (getting more enzymes in contact with more starch, more often). They don't appear to conduct any true control tests - the comparison is between the 200L caviation rig and a 50L braumeister, and comparisons without the beast 7.5kW running. I'd be very interested to see the effect the huuuuge circulation pump on its own. The reasons are:

a) It's common to get cavitation at pump inlets with higher-temperature water (due to a significant reduction in vapour pressure)
b) A 7.5 kW recirc pump is laughably oversized for a 200L mash tun, and would be generating such an enormous amount of shear-mixing that it's likely to be contributing to the results

There is mention that there have been studies on ultrasonics and enzymes, and that efficiency is improved up to a point when the power is too much and degrades them.

Essentially we're talking about improving the reaction rate of saccarification. This can be changed by:

• Pressure
• Temperature
• Mixing rate/concentrations/mass flow

In traditional brewing, we ignore pressure and make small changes to the mixing rate by grinding the grain to a largish size. We then increase the temperature. The combined effect is to increase the rate of saccarification reaction.
The cavitational method increases pressure (local to cavitational collapses) and significantly increases mass flow, which allows the temperature to be reduced to maintain a high extraction efficiency. At excessive levels these pressure waves denature the enzymes (just like excessive temperature).

 

[good4whatAlesU]

Jeepers, it certainly smashed the f#$k out of the grain too. Who needs crushing? ...

As you say Klangers this is a big industrial rig, so the same things not gonna happen in a little ultrasonic cleaner. Although it will certainly shake things up at least a bit. . just need to know what the tipping point is between "shaking things up" and ******* with the enzymes.

 

[Adr_0]

Jeepers, it certainly smashed the f#$k out of the grain too. Who needs crushing? ...

As you say Klangers this is a big industrial rig, so the same things not gonna happen in a little ultrasonic cleaner. Although it will certainly shake things up at least a bit. . just need to know what the tipping point is between "shaking things up" and ******* with the enzymes.

I agree with Klangers that the pump on the test rig is a little ridiculous. 7.5kW is said to be the mechanical power (shaft power?) and not the fluid power, so I imagine a lot goes into the viscosity of the mash fluid, or it is a very high clearance pump and hence low efficiency. My understanding is that the discharge pressure from the pump over the "cavitation reactor" - what, an orifice? - causes the cavitation. Hopefully it's not in the suction of the pump.

For you good4whatAlesU, you probably have to approach it with an open mind that a couple of batches might not be quite right. I'm not sure if you test your conversion with iodophor, or take SG readings of the first runnings, but it might be worth checking a control batch with ultrasonic off, then a couple with varying ultrasonic power. You could see when you hit your extract potential in your control batch vs varying ultrasonic power.

Not sure about the temperature thing, as a few people have highlighted, nor the oxidation thing - I'm sure after I first found this I read a lot into it and each source brought up oxidation. You do need to have air/O2 present for this to occur I would think... anyway, I'll try and find those sources.

 

[Adr_0]

Jeepers, it certainly smashed the f#$k out of the grain too. Who needs crushing? ...

As you say Klangers this is a big industrial rig, so the same things not gonna happen in a little ultrasonic cleaner. Although it will certainly shake things up at least a bit. . just need to know what the tipping point is between "shaking things up" and ******* with the enzymes.

with respect to crushing, I believe that is one of the benefits - no need to crush! That's pretty sweet.

 

[good4whatAlesU]

Hmmm food for thought.

Anyway I wouldn't pull the trigger on something this expensive until they email me back some photo's and details. .. If I can convert existing gear from my esky tun it might make sense. If it's not going to work (I've valves that can't be used/modified) it's just ornamental and costly (although I could clean my dentures with it in a few years )

 

[klangers]

A better option may be to just duplicate their rig, but with a more sensible pump. Ie insert a "cavitator" into your recirc on the mash.

You can get venturi injectors off ebay. Simply seal the injection port and insert in your recirc line. You'll need a significantly gruntier pump than a brown or chugger etc, just to get the requisite pressure across the venturi.

Then you can vary the intensity of cavitation by adjusting the flow rate with a valve. The only thing that gets me nervous is the risk of pulling grain through the falsie.

In fact I just may give this a go myself, considering I have all the parts lying around and a pump capable of 5 bar...

 

[good4whatAlesU]

Good work. Let us know how it goes klangers.

If I got it, it would be for the SS bowl and the temp control for mashing (not so much the ultrasonic feature).

My esky has served me well, but it's the only plastic thing left in my process. New insulated SS mash vessels are expensive ($300 - $600 +) and they don't have temp control.

 

[Futur]

There's some information available here on degassing water for brewing. The Kunze doesn't mention ultrasonic as a method to degass water of oxygen. Probably because you wouldn't reach the low recommended O2 levels required for mashing in (0.1 mg/L).

Personally for home brewing purposes, utilising bakers yeast and dextrose to scavenge oxygen from the mash water is the best and simplest method discovered so far. Next best would be boiling and then chilling the water, this however is quite wasteful of energy.

I'll be building a no-sparge BIAB RIMS LODO rig with a floating stainless mash cap in the next month or so to replace my grainfather. I'll make sure I include some photos in here for those interested.

 

[good4whatAlesU]

Actually there's a fair bit of literature and dare I say, You tube info about degassing using ultrasonic devices.

https://m.youtube.com/watch?v=EeWS_mlVQXY

Whether or not it effectively gets the DO down far enough - would have to do a more comprehensive lit. review.

 

[good4whatAlesU]

The Kunze doesn't mention ultrasonic as a method to degass water of oxygen. Probably because you wouldn't reach the low recommended O2 levels required for mashing in (0.1 mg/L).

Okay here's a paper (follow link and click on the download button) comparing four methods. They found sonification under pressure for 60 min gets O2 levels to less than 0.1 mg/L (but the reduction in O2 may have also been a factor of the sonification warming the water up). Although it also found that boiling at 1 atm did just as good (if not better a job). Nitrogen purging was found to be the most effective, however they used lab grade purified Nitrogen. .. they note that commercial grade nitrogen has oxygen in it.

https://www.researchgate.net/publication/23433550_Removal_of_Dissolved_Oxygen_from_Water_A_Comparison_of_Four_Common_Techniques

From an energy (and cost) perspective I guess one would have to work out the energy cost of bringing large volumes of water to the boil versus sonification. At the end of the day if there are multiple methods that work .. you have to figure out which one is:

1. most cost effective
2. least complicated
3. which one has any additional benefits (i.e. mash efficiency gains).