Some points that are interesting to me, and warrant further investigation:
1) Milling of malts is no longer required. As a microbrewery operator, now I don't need to come in the day before to run the mill for a planned brew. Massive win on scheduling and convenience.
2) "Concerning mashing and sparging, the new equipment allows to eliminate
sparging altogether since the pulverization of cavitating malts ... prevents practically any starch to remain trapped into the grains". Again, from a microbrewery operator's perspective, another few hours of labour saved per brew, since I don't have to run a few sparges over my grain.
3) Since cavitation apparently sanitizes the wort, we don't need to do a boil. This saves another 1.5 hours on a brew, removes the need for a boil vessel, and some other equipment in my brewery (steam boiler to heat the boil vessel, a bunch of plumbing for said steam).
4) related to 3, the hops can be isomerized without boiling. I've had great success with low-boil techniques like the hop stand, so I'd assume that CHC beer would capture a lot more of the volatile aromatics from hops. This could lead to some great IPAs.
I'd love to figure out what the MVP is for this rig, and whether it could be replicated at homebrew scale, as it seems to simplify the process massively.
Plus just general water savings. Between sparging, boil off and cleanup I've felt pretty bad about brewing in drought-stricken California in the last few years. Also, I'm strictly an amateur brewer, but I thought that the boil had other useful features? (For example, eliminating chlorine.) Do you filter the water ahead of time?
Where I am the water is very soft, and only lightly chlorinated, so I do not filter. (I do add minerals to improve the mash efficiency and yeast health though). If your water has lots of Chlorine (not Chloramine) then the boil will drive this off, but you might be better off starting with Reverse Osmosis water to get a clean slate, and then adding all the minerals you need.
Another important reason for the boil is driving off DMS (which causes a cooked corn off-flavour).
The paper covers both of these, I think:
"Due to the strong liquid degassing properties as a result of hydrodynamic
cavitation processes (Clark, Dewhurst, Payne, & Ellwood, 2001; Gogate & Pandit,
2011; Iben, Wolf, Freudigmann, Fröhlich, & Heller, 2015; Senthil Kumar, Siva Kumar,
& Pandit, 2000), undesired volatile aromatic compounds are safely expelled after few
minutes of cavitation"
Sounds like this would apply to the volatile chlorine as well, but I'm not certain about that.
Also sounds like this should be more rigorously tested, as I don't see anything by way of data to back up this claim; perhaps the cited papers explain more.
LEDs also switch much faster than older lights, which means people can pulse-width modulate them, causing annoying flicker for people who're sensitive to it.
Admittedly both these problems are avoidable, but in practice they're seen as LED problems because they're so common with LEDs.
Ok, so there has to be a comedy plot in there where two guys trying to make beer with hydrodynamic cavitation end up discovering a viable cold fusion reaction but keep drinking the experiment results :-)
That said, I found their off hand mention of using it as an alternate to high temperature pasteurization as much more intriguing. Mostly because I detest the "cooked" taste of ultra-pasteurized cream but have been finding it harder and harder to find cream that hasn't been over pasteurized in this way. Find me some cream that is "cold pasteurized" and tastes like cream, I'll be really happy.
You need to buy unpasteurized cream! Even better. But yes the ultra stuff is gross, standard pasteurization is ok, and widely available in the UK. You have to hunt for unpasteurized though.
I'm highly skeptical of the claim that such a system can plausibly "preserv[e] beer’s organoleptic qualities". The claim is repeated in the conclusion in a Trumpian fashion: "We anticipate that the new CHC brewing process affords beer of taste, flavor, body and color comparable with state-of-the-art craft beers, while offering further advantages, beyond the discussed ones, that will be the subject of a forthcoming study."
Somehow, though, that's the only mention of the flavor profile of the beer produced. They do describe measuring some key properties with a BeerLab, but those numbers hardly tell a complete story.
Given the horrid state the mash ends up in, and the fact that it isn't removed until the water has reached 78C, I'd expect plenty of tannins to be swept along in the race to efficiency.
I'd also briefly like to complain about the sad charts in this paper. What order are those bars in? Where are they drawing the conclusions in the text from? Why are the data points collected so inconsistent?
My main concern is, like others below, the opaque beer. I've always known that to be the undesirable effect of "pulverizing" I think of it as maybe twice ground beef can be cooked more evenly than a steak, but the crust and raw elements are what make a steak better. That's an unscientific way to say it, but as a homebrewer I know that efficiency is NOT quality. "Cold brewing" or brewing with CHC may have advantages in releasing/ preserving flavor in hops, but the study doesn't support this claim. I don't care if I get 30% efficiency based on original alphas to extracted alphas if something else is lost. (Like taste, sensory effect or mouth feel) I'm thinking this may be more comparable to "dry hopping", which can be used to give hop forward bitterness instead of the dregs that hops boiled for an hour provide. (Like the difference between the aromatic taste of fresh salsa versus the nearly coppery taste of cooked all day tomato sauce. I love fresh salsa, but you can't replace that "dregs" almost umami flavor brought out in Marinara. Compare Bell's Two Hearted to 3F Zombie Dust. IBU's don't tell the whole story. I'm not discounting these methods, but I don't think that the research is comprehensive enough or takes into account taste enough to talk about completely converting a brewery to these methods.
They talk about the use of ultrasonic vibrations in the use of creating cavitation in fluid. Why would that not work in this case? Why did they opt for a centrifugal pump?
I really only skimmed this very quickly, but it seems as though they are using a RIMS system for their cavitation based approach and an infusion mash (or maybe step controlled??? I'm not familiar with the Braumeister setup and their website is ridiculously slow) for their traditional approach. RIMS is already known by homebrewers to be dramatically more efficient than most other approaches. As interesting as it looks, I'm taking this with a huge grain of malt.
Sorry to reply to my own post, but since I finished reading the paper I can answer most of my implied questions :-)
The main difference between this setup and a RIMS is that they don't mill the malt when they allow the grain to be circulated. The cavitation pulverises the malt. This is actually a massive benefit because dry milling malt is a major cause of infection in a brewery.
The other benefit is that they are able to mash at a much lower temperature and still get decent extraction. Even down to 48C (118F) allows them to get 91% efficiency in one case. This is on par with RIMS (most reports I've heard is that people can manage mid 90s efficiency), but of course rims has to maintain a temperature of about 65C (150F).
Side note: Their reported temperatures for mashing without recirculating the grains is a bit crazy -- in the mid 70's C -- all much over 160F. They are going to be deactivating enzymes at those temps and that probably accounts for their decreased efficiency. I really can't understand what they were thinking.
There is some mention of protein make up, but my main worry about mashing at such a low temperature is the break down of larger proteins. They have a picture of frothy beer with a caption about foam stability, but the proof of the pudding is in the eating. Also, that picture shows a very hazy beer.
The other thing they talk about is isomerising the hops without boiling. That's pretty cool and would definitely reduce power usage. But again... that picture of nearly opaque beer haunts me.
Finally they talk about cavitating the fermenting beer in order to remove CO2. That seems reasonable, but I would worry somewhat about how the yeast drops in that condition.
To be honest, I wish they had stuck to mashing in this paper. It's strange to see a paper cram as much as this one does in one place. Normally you want to stretch it out over as many publications as possible ;-)
The last thing I'm curious about is how they produce the cavitation. I really couldn't understand their description at all. Is it just a matter of the design of chamber in which they pump the wort? That would be extremely cool, but I'd like to see a better description. A mash system that depends only on pumps would be ridiculously nice to have.
The OP paper's "Materials and methods" section references an earlier study of theirs on CHC: "Energy efficient inactivation of Saccharomyces cerevisiae via controlled hydrodynamic cavitation" [1].
From the OP paper: "A Venturi tube, with the same geometry used in a previous study (Albanese et
al., 2015), is used as the cavitation reactor and preferred over an orifice plate since it
was observed that orifices are quickly obstructed by the circulating solid particles. "
The referenced paper gives specifications for the Venturi tube:
"The cavitation reactors used for the experiments were
an orifice plate equipped with 156 holes (each having an
internal diameter 2 mm) and a Venturi tube (Fig. 2A and
B). Both are upscale models of effective configurations
used in laboratory scale experiments by researchers in
India [23, 28]. The orifice plate total opening was
490 mm2 (6.55% of the main pipe’s inner section). The
corresponding value for the opening of the Venturi tube’s
nozzle was 452 mm2 (6.05% of the pipe’s section)."
Might not be too difficult to obtain such a device.
> This is actually a massive benefit because dry milling malt is a major cause of infection in a brewery.
Don't mill in the same area you're brewing and this is pretty much handled. Lacto carries with dust, but just don't do anything post boil in that area and you're fine.
>This is on par with RIMS (most reports I've heard is that people can manage mid 90s efficiency), but of course rims has to maintain a temperature of about 65C (150F).
I sit in low 90s with a rather low tech HERMS setup.
>but my main worry about mashing at such a low temperature is the break down of larger proteins. They have a picture of frothy beer with a caption about foam stability, but the proof of the pudding is in the eating. Also, that picture shows a very hazy beer.
I'm curious about the lower temp mashes and getting enough longer chain sugars for those of us that spend a lot of time working with brett.
I guess mechanically yes, thermally no (if you're below pasteurization temperature). My intuition would be that mechanical bacteria killing is always going to be < 100% efficient, so eventually they will be back in force.
Potentially good enough, though? A proper pitch rate of whatever you actually want in there is going to help with outcompeting any undesirables.
My understanding is that most infections in commercial brewing are usually on the bottling/canning line - Since you've got a smaller volume, the "bad" bacteria or yeast make up a larger total percentage of organisms. Especially if sodium metabisulfite has been used prior to the packaging, since now anything that gets in there is running free by itself.
http://www.scientificamerican.com/article/cleaning-water-wit...
I think that doesn't apply here, the concept is that CHC purifies the liquid. I'm not sure how much I like that, but I agree that changing the boiling point wouldn't mean that bacteria are irradiated at boil.
1) Milling of malts is no longer required. As a microbrewery operator, now I don't need to come in the day before to run the mill for a planned brew. Massive win on scheduling and convenience.
2) "Concerning mashing and sparging, the new equipment allows to eliminate sparging altogether since the pulverization of cavitating malts ... prevents practically any starch to remain trapped into the grains". Again, from a microbrewery operator's perspective, another few hours of labour saved per brew, since I don't have to run a few sparges over my grain.
3) Since cavitation apparently sanitizes the wort, we don't need to do a boil. This saves another 1.5 hours on a brew, removes the need for a boil vessel, and some other equipment in my brewery (steam boiler to heat the boil vessel, a bunch of plumbing for said steam).
4) related to 3, the hops can be isomerized without boiling. I've had great success with low-boil techniques like the hop stand, so I'd assume that CHC beer would capture a lot more of the volatile aromatics from hops. This could lead to some great IPAs.
I'd love to figure out what the MVP is for this rig, and whether it could be replicated at homebrew scale, as it seems to simplify the process massively.